WO2010005594A1 - Compositions and methods of producing ursodeoxycholic acid - Google Patents

Compositions and methods of producing ursodeoxycholic acid Download PDF

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Publication number
WO2010005594A1
WO2010005594A1 PCT/US2009/004038 US2009004038W WO2010005594A1 WO 2010005594 A1 WO2010005594 A1 WO 2010005594A1 US 2009004038 W US2009004038 W US 2009004038W WO 2010005594 A1 WO2010005594 A1 WO 2010005594A1
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Prior art keywords
cells
microenviromental
composition
hepatocytes
culture
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PCT/US2009/004038
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French (fr)
Inventor
Gail K. Naughton
Brian A. Naughton
Dawn Applegate
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Regenemed Inc.
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Publication of WO2010005594A1 publication Critical patent/WO2010005594A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/56—Compounds containing cyclopenta[a]hydrophenanthrene ring systems; Derivatives thereof, e.g. steroids
    • A61K31/575—Compounds containing cyclopenta[a]hydrophenanthrene ring systems; Derivatives thereof, e.g. steroids substituted in position 17 beta by a chain of three or more carbon atoms, e.g. cholane, cholestane, ergosterol, sitosterol
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N5/00—Undifferentiated human, animal or plant cells, e.g. cell lines; Tissues; Cultivation or maintenance thereof; Culture media therefor
    • C12N5/06—Animal cells or tissues; Human cells or tissues
    • C12N5/0602—Vertebrate cells
    • C12N5/067—Hepatocytes
    • C12N5/0671—Three-dimensional culture, tissue culture or organ culture; Encapsulated cells
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P33/00—Preparation of steroids
    • C12P33/06—Hydroxylating

Definitions

  • the present invention relates to a composition comprising a biologically active molecule, such as a bile acid, derived from a three-dimensional cell and tissue culture system.
  • the present invention also relates to a method for the production of a composition comprising a biologically active molecule using this culture system for the long term culture of liver cells and tissues in vitro in an environment that more closely approximates that found in vivo.
  • the culture system described herein provides for proliferation and appropriate liver cell maturation to form structures analogous to tissue counterparts in vivo. The resulting liver tissues survive for prolonged periods, perform liver-specific functions.
  • Bear bile has been used as a traditional medicine in Asia for over 3000 years.
  • bear bile is used to brighten the eyes, cool the heart and liver and eliminate parasites from the body.
  • bear bile has been utilized to treat hepatitis and hepatic coma, alleviate spasms and delirium caused by extensive burns, reduce swelling, inflammation and pain in trauma, sprains, fractures or hemorrhoids.
  • Due to its beneficial medical effect there is an increased demand in bear bile products and the global illegal trade in bear parts is estimated at two billion dollars annually. The illegal hunting and trade for bears has endangered the population of seven out of the world's eight bear species.
  • bear farms have been established in many Asian countries, where bears are confined to small cages and fitted with metal catheters to milk their gallbladders to result in a continual supply of bile. In bear farms, bears suffers trauma and frequently die from illness, injury, infection etc.
  • UDCA ursodeoxycholic acid
  • LAI-2875394v7 also found at much lower concentration in other species including human and can be extracted from turkey, pig or cow bile.
  • UDCA tauroursodeoxycholic acid
  • TUDCA tauroursodeoxycholic acid
  • the present invention provides a method for producing a bile acid, such as UDCA, via a three-dimensional liver cell culture.
  • the present invention provides a composition comprising a biologically active molecule from a conditioned culture medium that is generated using a three-dimensional culture.
  • the biologically active molecule is a bile acid, bile acid derivative, bile acid salt, bile acid conjugate, or any combination thereof.
  • the biologically active molecule is ursodeoxycholic acid ('UDCA') or its salt, conjugate or combination thereof.
  • the present invention provides a method for producing a composition comprising a biologically active molecule, such as a bile acid, from a conditioned culture medium using a three-dimensional cell and tissue culture system.
  • a biologically active molecule such as a bile acid
  • the biologically active molecule is a bile acid, or its derivative, salt or conjugate or combination thereof.
  • the biologically active molecule is ursodeoxycholic acid ('UDCA') or its salt, conjugate or combination thereof.
  • the method comprises inoculating hepatocytes onto a living microenviromental tissue prepared in vitro, incubating the inoculated living microenviromental tissue in a medium so that the inoculated hepatocytes proliferate in
  • hepatocytes are inoculated and grown on a pre- established microenviromental tissue.
  • the microenviromental tissue can comprise microenviromental cells actively growing on a three-dimensional framework.
  • the microenviromental tissue can provide the support, growth factors, and regulatory factors necessary to sustain long-term active proliferation of hepatocytes in culture.
  • the proliferating cells When grown in this three-dimensional system, the proliferating cells can mature, segregate properly to form components of liver tissues analogous to counterparts found in vivo and synthesize one or more bile acids or salts, conjugate or combinations thereof that are produced in vivo.
  • the culture medium can then be collected and used in various application as discussed below. Also, the collected culture medium can be further processed to be formulated for its intended use and/or the active biologically active molecule can be concentrated by any method or technique known to those of skill in the art.
  • the three-dimensional cell and tissue culture system can be cultured by any methods known in the art.
  • cells are cultured in a manner allowing for easy and aseptic handing or large scale growth.
  • the present invention relates to use of a composition comprising a biologically active molecule from a conditioned culture medium using a three- dimensional cell and tissue culture system.
  • the compositions of the present invention are used as food additives or dietary supplements.
  • the compositions are used in pharmaceutical applications for treating a disease or condition, such as by alleviating one or more symptoms of the disease or condition, in subject in need thereof.
  • the diseases or conditions include, but are not limited to, liver or gallbladder disorders, disorders relating to cholesterol or lipid homeostasis, degenerative diseases or disorders, cardiovascular or cerebrovascular diseases, or inflammatory diseases, or any combination thereof.
  • FIG. IA A cytosmear depicting type I (mononuclear) and type II (binuclear) hepatocytes stained with DIFF-QUIK and isolated by 'PERCOLL' gradient centrifugation.
  • LAI-2875394v7 The smaller microenviromental elements (arrows) are distinguished from the hepatocytes by virtue of their size, nuclear configuration, and nuclear staining density.
  • Original magnification 1 ,000 X.
  • FIG. 2A Inverted phase photomicrograph of an 8 day old co-culture of various hepatic hepatocytes derived from the 70% 'PERCOLL' pellet and hepatic microenviromental cells on a nylon screen framework. The inoculation with this heterogeneous mixture of cells promotes the growth of morphologically distinct clusters.
  • FIG. 2B Hematoxylin-eosin (H-E) stained section through a liver cell co- culture 24 hr after inoculation of PC. 1 ,000 X. The semicircular space (arrow) denotes the location of the nylon filament. Several round hepatocytes are associated with stroma (S).
  • FIG. 3A The relationship between total adherent cell count and radiothymidine incorporation in liver co-culture. Vertical lines through the means indicate ⁇ 1 sem. — D— indicates cell count, and —indicates thymidine incorporation.
  • FIG. 3B Mean differential cell counts in liver co-cultures of various ages. -- ⁇ - - indicates hepatocytes, .-o- indicates microenviromental cells, and --•-- indicates acidophilic cells.
  • FIG. 4B Section through a 30-day liver co-culture stained with an anti- cytokeratin 19. Immunofluorescence of the large, round cells of the section (arrows). 500 X.
  • FIG. 5A EFEE is converted by cytochrome P450 enzymes to fluorescein.
  • FIG. 5B Cytochrome P450 enzyme activity in hepatic cells 21 hr after the introduction of TCDD.
  • the EFEE to fluorescein conversion reaction is quantified as the product of the percentage of positively fluorescent cells and the peak fluorescence channel number. The number of events measured for each sample is 10,000-20,000.
  • FIG. 8 A Photomicrographs of co-cultures of liver hepatocytes and microenviromental cells on PGA felt 30 days after grafting into Long-Evans rats. H-E staining. Low power view of a subcutaneous graft showing a focus of hepatic tissue (H) contiguous to connective tissue (C) in the process of reorganization. A tract of residual, partially hydrolyzed PGA polymers (p) is present. Arrows identify putative biliary structures associated with the regenerating hepatic tissue. 100 X.
  • FIG. 8B Photomicrographs of co-cultures of liver hepatocytes and microenviromental cells on PGA felt 30 days after grafting. The interface between grafted liver co-cultures (L) and connective tissue (C) elements of the omentum. Sinusoids (s) are evident.
  • FIG. 8C Photomicrographs of co-cultures of liver hepatocytes and microenviromental cells on PGA felt 30 days after grafting. Graft site in the mesentery showing hepatocytes with sinusoids (lower right), connective tissue in the process of repair
  • the term 'about' or 'approximately' means within 20%, preferably within 10%, and more preferably within 5% (or 1% or less) of a given value or range.
  • LAI-2875394v7 refers to the act of injecting or otherwise physically delivering a substance as it exists outside the body (e.g., a composition provided herein) into a patient, such as by mucosal, intradermal, intravenous, intramuscular delivery and/or any other method of physical delivery described herein or known in the art.
  • administration of the substance typically occurs after the onset of the disease or symptoms thereof.
  • administration of the substance typically occurs before the onset of the disease or symptoms thereof.
  • composition' is intended to encompass a product containing the specified ingredients in, optionally, the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in, optionally, the specified amounts.
  • 'Conditioned medium,' 'conditional cell medium,' or 'conditioned cell and tissue culture medium' refers to a formulation containing extracellular protein(s) and cellular metabolites, which has previously supported the growth of any desired cell type, said cells having been cultured in three dimensions.
  • a biologically active molecule is 'derived' or 'culture-derived' from a conditional medium refers to a molecule of conditioned cell culture medium that is not present in the starting cell culture medium that is used to culture and feed the cells, but is produced by the cultured cells and enters the medium, or a molecule that is initially present in the pre-conditioned media, but whose concentration is increased during the culture process.
  • the term 'effective amount' as used herein refers to the amount of a therapy
  • composition e.g., a composition provided herein
  • This term also encompasses an amount necessary for the reduction or amelioration of the advancement or progression of a given disease, reduction or amelioration of the recurrence, development or onset of a given disease, and/or to improve or enhance the prophylactic or therapeutic effect(s) of another therapy.
  • excipients' refers to inert substances which are commonly used as a diluent, vehicle, preservatives, binders, or stabilizing agent for drugs
  • LAI-2875394v7 includes, but not limited to, proteins (e.g., serum albumin, etc.), amino acids (e.g., aspartic acid, glutamic acid, lysine, arginine, glycine, histidine, etc.), fatty acids and phospholipids (e.g., alkyl sulfonates, caprylate, etc.), surfactants (e.g., SDS, polysorbate, nonionic surfactant, etc.), saccharides (e.g., sucrose, maltose, trehalose, etc.) and polyols (e.g., mannitol, sorbitol, etc.). See also Remington's Pharmaceutical Sciences (18 th Ed., 1995), which is hereby incorporated by reference in its entirety.
  • proteins e.g., serum albumin, etc.
  • amino acids e.g., aspartic acid, glutamic acid, lysine, arginine, glycine
  • the term 'extracellular matrix' or 'ECM' encompasses essentially all secreted molecules that are immobilized outside of the cell.
  • the ECM provides order in the extracellular space and serves functions associated with establishing, separating, and maintaining differentiated tissues and organs.
  • the ECM is a complex structure that is found, for example, in connective tissues and basement membranes, also referred to as the basal lamina.
  • Connective tissue typically contains isolated cells surrounded by ECM that is naturally secreted by the cells.
  • Exemplary ECM include but are not limited to, collagen type I, collagen type II, collagen type III, collagen type IV, collagen type V, collagen type VI, collagen type VII, collagen type VIII, collagen type IX, collagen type X, collagen type XI, collagen type XII, collagen type XIII, collagen type XIV, collagen type XV, collagen type XVI, collagen type XVII, collagen type XVIII, fibronectin, laminin, particularly laminin-1, laminin-2, laminin-4, and laminin-5, lumican, tenascin, versican, perlecan, thrombospondin, particularly thrombospondin-2 and thrombospondin-4, or laminin, particularly laminin-1, -2, -4, and -5, agrin, nidogen, bamacan, decorin, biglycan, fibromodulin, elastin, fibrillin, hyaluronan, vitronectin, chondroitin sulphate
  • a subject is administered one or more therapies (e.g., a composition of the invention) to 'manage' a disease or disorder, one or more symptoms thereof, so as to prevent the progression or worsening of the disease.
  • therapies e.g., a composition of the invention
  • fibroblasts refers to fibroblasts with or without other cells and/or elements found in loose connective tissue, including, but not limited to, endothelial cells, pericytes, macrophages, monocots, plasma cells , mast cells, adipocytes, mesenchymal stem
  • LAl-2875394v7 cells liver reserve cells.
  • microenviromental cells of liver may include fibroblasts, Kupffer cells and vascular and bile duct endothelial cells.
  • European Pharmacopeia or other generally recognized Pharmacopeia for use in animals, and more particularly in humans.
  • the terms 'prevent,' 'preventing,' and 'prevention' refer to the total or partial inhibition of the development, recurrence, onset or spread of a disease and/or symptom related thereto, resulting from the administration of a therapy or combination of therapies provided herein ⁇ e.g., a combination of compositions provided herein).
  • a subject is preferably a mammal, such as a non-primate (e.g., cows, pigs, horses, cats, dogs, rats, etc.) or a primate (e.g., monkey and human), most preferably a human.
  • a non-primate e.g., cows, pigs, horses, cats, dogs, rats, etc.
  • a primate e.g., monkey and human
  • the term 'therapy' refers to any protocol, method and/or agent that can be used in the prevention, management, treatment and/or amelioration of a disease.
  • the terms 'therapies' and 'therapy' refer to a biological therapy, supportive therapy, and/or other therapies useful in the prevention, management, treatment and/or amelioration of a disease known to one of skill in the art, such as medical personnel.
  • 'Three-dimensional framework' refers to a three-dimensional scaffold composed of any material and/or shape that (a) allows cells to attach to it (or can be modified to allow cells to attach to it); and (b) allows cells to grow in more than one layer.
  • This support is inoculated with microenviromental cells to form the living three-dimensional microenviromental tissue.
  • the structure of the framework can include a mesh, a sponge or can be formed from a hydrogel.
  • Three-dimensional microenviromental tissue' or 'living microenviromental matrix' refers to a three-dimensional framework which has been inoculated with microenviromental cells that are grown on the support. The extracellular matrix proteins elaborated by the microenviromental cells are deposited onto the framework, thus forming a living microenviromental tissue. The living microenviromental tissue can support the growth of hepatocytes inoculated to form the three-dimensional cell culture.
  • LAI-2875394v7 refers to the reduction or amelioration of the progression, severity, and/or duration of a disease resulting from the administration of one or more therapies (including, but not limited to, the administration of one or more compositions provided herein).
  • the present invention relates to a method for the production of a composition comprising a biologically active molecule, such as a bile acid, derived from a conditioned culture medium by using a three-dimensional, multi-layer cell culture system. Also provided herein is a composition produced by this method, as well as methods of using the composition for use in the treatment of diseases or disorders, and/or the alleviation of a symptom of a disease or disorder thereof.
  • a biologically active molecule such as a bile acid
  • the cells were grown in a monolayer.
  • Cells cultured on a three-dimensional microenviromental cell framework, in accordance with the present invention grow in multiple layers, forming a tissue.
  • This three- dimensional approaches physiologic conditions found in vivo to a greater degree than previously described monolayer tissue culture systems.
  • the three-dimensional cell culture system is applicable to the proliferation of liver cells, formation of liver tissues and synthesis of bile acids by liver cells.
  • hepatocytes are inoculated and cultured on a pre-established three-dimensional microenviromental tissue.
  • the microenviromental tissue comprises microenviromental cells grown on a three-dimensional matrix or framework.
  • the microenviromental cells comprise fibroblasts with or without additional cells and/or elements described more fully herein.
  • the fibroblasts and other cells and/or elements that comprise the microviromental tissue can be fetal or adult in origin, and can be derived from convenient sources, such as skin, liver, pancreas, etc.
  • Such tissues and/or organs can be obtained by appropriate biopsy or upon autopsy.
  • cadaver organs can be used to provide a generous supply of microenviromental cells and elements.
  • Neonatal fibroblasts can support the growth of many different cells and tissues in the three-dimensional culture system, and, therefore, can be inoculated onto the matrix to form a 'generic' microenviromental tissue for culturing any of a variety of cells and tissues,
  • LAI-2875394v7 including hepatocytes including hepatocytes.
  • a 'specific' rather than 'generic' microenviromental tissue in which case microenviromental cells and elements can be obtained from a liver tissue.
  • Fibroblasts and other microenviromental cells and/or elements can be derived from the same type of tissue to be cultured in the three-dimensional system. This might be advantageous, for example, when culturing liver tissues in which specialized microenviromental cells can play particular structural/functional roles; e.g., Kupffer cells of liver.
  • the microenviromental cells will proliferate on the framework and support the growth of hepatocytes inoculated into the three-dimensional culture system of the invention.
  • the three-dimensional microenviromental tissue will sustain active proliferation of the culture for long periods of time. Growth and regulatory factors can be added to the culture, but are not necessary since they are elaborated by the microenviromental tissue.
  • one or more agents that increase the synthesis or formation of bile acids are added to the culture.
  • the extent to which the microviromental cells are grown prior to inoculation of hepatocytes can vary depending on the type of tissue to be grown in three-dimensional tissue culture. Importantly, because openings in the mesh permit the exit of microenviromental cells in culture, confluent microenviromental cultures do not exhibit contact inhibition, and the microenviromental cells continue to grow, divide, and remain functionally active.
  • the invention is based, in part, upon the discovery that growth of the microenviromental cells in three dimensions will sustain active proliferation of both the microenviromental and tissue-specific cells in culture for much longer time periods than will monolayer systems. Moreover, the three-dimensional system supports the maturation, differentiation, and segregation of liver cells in culture in vitro to form components of adult liver tissues analogous to counterparts found in vivo. The three-dimensional system is useful for the production of biologically active molecules produced by liver cells, such as bile acids.
  • the three-dimensional framework provides a greater surface area for protein deposition, and consequently, for the adherence of microenviromental cells.
  • microenviromental cells continue to actively grow, in contrast to cells in monolayer cultures, which grow to confluence, exhibit contact inhibition, and cease to grow and divide.
  • the elaboration of growth and regulatory factors by replicating microenviromental cells can be partially responsible for stimulating proliferation and regulating differentiation of cells in culture.
  • the three-dimensional framework maximizes cell-cell interactions by allowing greater potential for movement of migratory cells, and for the establishment of communications between hepatocytes and the various types of microenviromental cells, such as macrophages, in the adherent layer.
  • the present invention provides a method for producing a composition comprising a biologically active molecule from a conditioned culture medium using a three- dimensional cell and tissue culture system.
  • the biological active molecule is culture-derived from a conditioned culture medium using a three-dimensional liver cells culture.
  • the biologically active molecule is a bile acid
  • L ⁇ I-2875394v7 bile acid derivative, bile acid salt, bile acid conjugate, or any combination thereof is meant to include the bile acid itself, as well as any bile acid derivative, salt, or conjugate thereof, either individually or any combination thereof
  • the biologically active molecule is ursodeoxycholic acid ('UDCA') or derivative, salt, conjugate or combination thereof.
  • the present invention provides a method for producing a bile acid, or its derivative, salt or conjugate thereof, comprising isolating the bile acid, or its derivative, salt or conjugate thereof from a conditioned culture medium, wherein the culture medium is conditioned by hepatocytes in three-dimensional culture.
  • the present invention provides a method for producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, comprising combining a conditioned culture medium with an appropriate carrier, wherein the culture medium is conditioned by hepatocytes in three-dimensional culture.
  • Appropriate carriers can be neutraceutically acceptable carriers or pharmaceutically acceptable carriers which are described below.
  • the present invention provides a method for producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, comprising isolating the bile acid or its derivative salt or conjugate thereof from a conditioned culture medium and the cell medium is conditioned by hepatocytes cultured on a living microenviromental cell tissue prepared in vitro, comprising microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells attached to and substantially enveloping a framework composed of a biocompatible, non-living material formed into a three-dimensional structure having interstitial spaces bridged by the microenviromental cells, so that the hepatocytes proliferate and secrete a bile acid, or its derivative, salt or conjugate thereof into the conditioned medium.
  • the present invention provides a method for producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, comprising: (a) inoculating liver hepatocytes onto a living microenviromental cell tissue prepared in vitro, comprising microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells attached to and substantially enveloping a framework composed of a biocompatible, non-living material formed into a three-dimensional structure
  • the 'pre-conditioned' cell culture medium can be any cell culture medium which adequately addresses the nutritional needs of the cells being cultured.
  • Cell culture media are well known in the literature and many are commercially available. Examples of cell media include, but are not limited to William's Medium E (WME), Dulbecco's Modified Eagle's Medium (DMEM), Ham's F12, RPMI 1640, Iscove's, McCoy's and other media formulations readily apparent to those skilled in the art, including those found in Methods For Preparation of Media, Supplements and Substrate For Serum-Free Animal Cell Culture Alan R.
  • WME William's Medium E
  • DMEM Dulbecco's Modified Eagle's Medium
  • Ham's F12 Ham's F12
  • RPMI 1640 RPMI 1640
  • Iscove's Iscove's
  • McCoy's and other media formulations readily apparent to those skilled in the art, including those found in Methods For Preparation of Media, Supplements and Subs
  • the medium can be supplemented, with any components necessary to support the desired cell or tissue culture.
  • serum such as bovine serum, which is a complex solution of albumins, globulins, growth promoters and growth inhibitors can be added if desired.
  • bovine serum which is a complex solution of albumins, globulins, growth promoters and growth inhibitors can be added if desired.
  • the serum generally should be pathogen free and carefully screened for mycoplasma bacterial, fungal, and viral contamination. Also, the serum should generally be obtained from the United States and not obtained from countries where indigenous livestock carry transmittable agents. Hormone addition into the medium may or may not be desired.
  • the pre-conditioned medium can also contain one or more agents that facilitate the synthesis, formation or secretion of biologically active molecules of interests.
  • the present invention can use any cell type appropriate to achieve the desired conditioned medium.
  • the medium are conditioned by hepatocytes to generate a conditioned medium containing a bile acid or its derivative, salt or conjugate or combinations thereof.
  • Hepatocytes from any species can be used in generating a conditioned medium containing a bile acid or its derivative, salt or conjugate or combinations thereof.
  • Hepatocytes from any species can be used in generating
  • hepatocytes are human, primate, bear, cow, dog, rodent, pig or turkey hepatocytes. In preferred embodiments, hepatocytes are bear hepatocytes.
  • bear hepatocytes are from American black bear (Ursus Americanus), Asiatic black bear ⁇ Selenarctos thibetanus), polar bear (Ursus maritimus), brown bear (Ursus arctos), sun bear (Helarctosjnalayanus), giant panda (Alluropoda melanoleuc ⁇ ), sloth bear (Melursus ursinus) or spectacled bear (Tremarctus ornatus).
  • Genetically engineered cells can be used to culture the media. Such cells can be modified, for example, to express a desired protein or proteins so that the concentration of the expressed protein or proteins in the medium is optimized for the particular desired application.
  • the cells and tissue cultures used to condition the medium can be engineered to express a target gene product which can impart a wide variety of functions, including, but not limited to, improved properties in expressing proteins resembling physiological reactions, increased expression of a particular protein useful for a specific application, such as wound healing or inhibiting certain proteins, such as proteases, lactic acid, etc.
  • microenviromental cells used in the three-dimensional cultures comprise fibroblasts, mesenchymal stem cells, liver reserve cells, neural stem cells, pancreatic stem cells, and/or embryonic stem cells with or without additional cells and/or elements described more fully herein.
  • Fibroblasts will support the growth of many different cells and tissues in the three-dimensional culture system, and, therefore, can be inoculated onto the matrix to form a 'generic' microenviromental support matrix for culturing any of a variety of cells and tissues.
  • a 'specific' rather than 'generic' microenviromental support matrix in which case microenviromental cells and elements can be obtained from a particular tissue, organ, or individual.
  • fibroblasts and other microenviromental cells and/or elements can be derived from the same type of tissue to be cultured in the three-dimensional system. This might be advantageous when culturing tissues in which specialized microenviromental cells can play particular
  • LAl-2875394v7 structural/functional roles; e.g., smooth muscle cells of arteries, glial cells of neurological tissue, Kupffer cells of liver, etc.
  • the microenviromental cells will proliferate on the framework and deposit the connective tissue proteins naturally secreted by the microenviromental cells, such as growth factors, regulatory factors and/or extracellular matrix proteins.
  • the microenviromental cells and their naturally secreted connective tissue proteins substantially envelop the framework thus forming the living microenviromental tissue which will support the growth of tissue-specific cells inoculated into the three-dimensional culture system of the invention.
  • the three-dimensional microenviromental tissue will sustain active proliferation of the culture for long periods of time.
  • openings in the mesh permit the exit of microenviromental cells in culture, confluent microenviromental cultures do not exhibit contact inhibition, and the microenviromental cells continue to grow, divide, and remain functionally active.
  • Growth and regulatory factors are elaborated by the microenviromental tissue into the media.
  • Growth factors for example, but not limited to, ⁇ FGF, ⁇ FGF, insulin growth factor or TGF-betas), or natural or modified blood products or other bioactive biological molecules (for example, but not limited to, hyaluronic acid or hormones), enhance the colonization of the three-dimensional framework or scaffolding and condition the culture media.
  • the extent to which the microenviromental cells are grown prior to use of the cultures in vivo can vary depending on the type of tissue to be grown in three-dimensional tissue culture.
  • the living microenviromental tissues which condition the medium can be used as corrective structures by implanting them in vivo.
  • the living microenviromental tissues can be inoculated with another cell type and implanted in vivo.
  • the microenviromental cells can be genetically engineered to adjust the level of protein products secreted into the culture medium to improve the concentration of recovered product obtained from the conditioned medium.
  • L ⁇ I-2875394v7 supports the maturation, differentiation, and segregation of cells in culture in vitro to form components of adult tissues analogous to counterparts found in vivo and secure proteins into the conditional medium more closely resembling physiological ratios.
  • the three-dimensional support framework can be of any material and/or shape that: (a) allows cells to attach to it (or can be modified to allow cells to attach to it); and (b) allows cells to grow in more than one layer.
  • a number of different materials can be used to form the framework, including but not limited to: nylon (polyamides), dacron (polyesters), polystyrene, polypropylene, polyacrylates, polyvinyl compounds (e.g., polyvinylchloride), polycarbonate (PVC), polytetrafluorethylene (PTFE; teflon), thermanox (TPX), nitrocellulose, cotton, polyglycolic acid (PGA), cat gut sutures, cellulose, gelatin, dextran, etc.
  • any of these materials can be woven into a mesh, for example, to form the three- dimensional framework.
  • Certain materials such as nylon, polystyrene, etc. , can be used, but are less preferred as they tend to be poor substrates for cellular attachment.
  • nylon screens could be treated with 0.1 M acetic acid, and incubated in polylysine, FBS, and/or collagen to coat the nylon.
  • Polystyrene could be similarly treated using sulfuric acid.
  • biodegradable materials such as PGA, catgut suture material, collagen, polylactic acid, or hyaluronic acid can be used in the three-dimensional support framework.
  • these materials can be woven into a three-dimensional framework, such as a collagen sponge.
  • non-degradable materials such as nylon, dacron, polystyrene, polyacrylates, polyvinyls, teflons, cotton, etc. can be used.
  • a convenient nylon mesh which could be used in accordance with the invention is NITEX, a nylon filtration mesh having an average pore size of 140 ⁇ m and an average nylon fiber diameter of 90 ⁇ m (#3-210/36, Tetko, Inc., N. Y.).
  • Microenviromental cells comprising fibroblasts, with or without other cells and elements described below, can be inoculated onto the framework.
  • LAI-2875394v7 cells can be derived from organs, such as skin, liver, pancreas, etc., which can be obtained by biopsy (where appropriate) or upon autopsy.
  • fibroblasts can be obtained in quantity rather conveniently from any appropriate cadaver organ.
  • fetal fibroblasts can be used to form a 'generic' three-dimensional microenviromental tissue that will support the growth of a variety of different cells and/or tissues.
  • a 'specific' microenviromental tissue can be prepared by inoculating the three-dimensional framework with microenviromental cells derived from the liver.
  • Liver microenviromental cells include, but are not limited to, Kupffer cells, endothelial cells, fat storing cells and fibroblasts.
  • Microenviromental cells can be readily isolated by disaggregating an appropriate organ or tissue. This can be readily accomplished using techniques known to those skilled in the art. For example, the tissue or organ can be disaggregated mechanically and/or treated with digestive enzymes and/or chelating agents that weaken the connections between neighboring cells making it possible to disperse the tissue into a suspension of individual cells without appreciable cell breakage. Enzymatic dissociation can be accomplished by mincing the tissue and treating the minced tissue with any of a number of digestive enzymes either alone or in combination.
  • tissue disaggregation techniques see, e.g., Freshney, Culture of Animal Cells. A Manual of Basic Technique (2 nd Ed. 1987), A. R. Liss, Inc., New York, Ch. 9, pp. 107-126.
  • the suspension can be fractionated into subpopulations from which the fibroblasts and/or other microenviromental cells and/or elements can be obtained.
  • This can also be accomplished using standard techniques for cell separation including, but not limited to, cloning and selection of specific cell types, selective destruction of unwanted cells (negative selection), separation based upon differential cell agglutinability in the mixed population, freeze-thaw procedures, differential adherence properties of the cells in the mixed population, filtration, conventional and zonal centrifugation, centrifugal elutriation (counter-streaming centrifugation), unit gravity separation, countercurrent distribution, electrophoresis and
  • microenviromental cells can, for example, be carried out as follows: fresh tissue samples are thoroughly washed and minced in Hanks Balanced Salt Solution (HBSS) in order to remove serum. The minced tissue is incubated from 1-12 hours in a freshly prepared solution of a dissociating enzyme, such as trypsin.
  • HBSS Hanks Balanced Salt Solution
  • microenviromental cells After such incubation, the dissociated cells are suspended, pelleted by centrifugation and plated onto culture dishes. All microenviromental cells will attach before other cells. Thus, appropriate microenviromental cells can be selectively isolated and grown. The isolated microenviromental cells can then be grown to confluency, lifted from the confluent culture and inoculated onto the three-dimensional framework (see, e.g., Naughton et ah, 1987, J. Med. 18(3&4):219-250). Inoculation of the three-dimensional framework with a high concentration of microenviromental cells, e.g., approximately 10 6 to 5X10 7 cells/ml, will result in the establishment of the three-dimensional microenviromental tissue in shorter periods of time.
  • a high concentration of microenviromental cells e.g., approximately 10 6 to 5X10 7 cells/ml
  • liver microenviromental cells which include Kupffer cells, endothelial cells, adipocytes and fibroblasts, are inoculated onto the framework collectively.
  • the growth of cells in the presence of the three-dimensional microenviromental support framework can be further enhanced by adding to the framework or coating it with proteins ⁇ e.g., collagens, elastin fibers, reticular fibers) glycoproteins, glycosaminoglycans (e.g. , heparan sulfate, chondroitin-4-sulfate, chondroitin-6-sulfate, dermatan sulfate, keratan sulfate), a cellular matrix, and/or other materials.
  • proteins ⁇ e.g., collagens, elastin fibers, reticular fibers
  • glycoproteins e.g., heparan sulfate, chondroitin-4-sulfate, chondroitin-6-sulfate, dermatan sulfate, keratan sulfate
  • glycosaminoglycans e.g. , heparan sulfate,
  • the three-dimensional framework should be incubated in an appropriate nutrient medium.
  • Many commercially available media such as WME, DMEM, RPMI 1640, Fisher's, Iscove's, McCoy's, and the like can be suitable for use. It is important that the three-dimensional microenviromental tissue be suspended in the medium during the incubation period in order to maximize proliferative activity.
  • the culture should be 'fed' periodically to remove the spent media, depopulate released cells, and add fresh media.
  • the microenviromental cells will grow linearly along and envelop the filaments of the three-dimensional framework before beginning to grow into the openings of the framework. It is important to grow the cells to an appropriate degree which reflects the proportion of microenviromental cells present in the in vivo tissue prior to inoculation of the microenviromental tissue with hepatocytes.
  • the openings of the framework should be of an appropriate size to allow the microenviromental cells to stretch across the openings. Maintaining actively growing microenviromental cells which stretch across the framework enhances the production of growth factors that are elaborated by the microenviromental cells, and hence will support long term cultures.
  • the microenviromental cells can rapidly achieve confluence but be unable to easily exit from the mesh, and trapped cells can exhibit contact inhibition and cease production of the appropriate factors necessary to support proliferation and maintain long term cultures. If the openings are too large, the microenviromental cells can be unable to stretch across the opening, and this will also decrease microenviromental cell production of the appropriate factors necessary to support proliferation and maintain long term cultures.
  • a mesh type of framework as exemplified herein, it has been found that openings ranging from about 140 ⁇ m to about 220 ⁇ m can work satisfactorily. However, depending upon the three-dimensional structure and intricacy of the framework, other sizes can work equally well.
  • any shape or structure that allows the microenviromental cells to stretch and continue to replicate and grow for lengthy time periods will work in accordance with the invention.
  • Different proportions of the various types of collagen deposited on the matrix can affect the growth of the later inoculated hepatocytes.
  • the proportions of ECM proteins deposited can be manipulated or enhanced by selecting fibroblasts which elaborate
  • the appropriate collagen type can be accomplished using monoclonal antibodies of an appropriate isotype or subclass that is capable of activating complement, and which define particular collagen types. These antibodies and complement can be used to negatively select the fibroblasts which express the desired collagen type.
  • the microenviromental cells used to inoculate the framework can be a mixture of cells which synthesize the appropriate extracellular matrix or collagen types desired. The distribution and origins of the five types of collagen is shown in Table I. The types of cells used to inoculate onto the microenviromental framework can be selected based on the extracellular matrix as shown in the following table.
  • the appropriate microenviromental cell(s) can be selected to inoculate the three-dimensional framework.
  • microenviromental cells isolated from the liver are preferred for use to support the growth of hepatocytes.
  • proliferating cells can be released from the framework. These released cells can stick to the walls of the culture vessel where they can continue to proliferate and form a confluent monolayer. This should be prevented or minimized, for example, by removal of the released cells during feeding, or by transferring the three-dimensional microenviromental tissue to a new culture vessel. The presence of a confluent monolayer in the vessel can 'shut down' the growth of cells in the three-dimensional culture. Removal of the confluent monolayer or transfer of the microenviromental tissue to fresh media in a new vessel will restore proliferative activity of the three-dimensional culture system.
  • the culture system could be agitated to prevent the released cells from sticking, or instead of periodically feeding the cultures, the culture system could be set up so that fresh media continuously flows through the system.
  • the flow rate could be adjusted to both maximize proliferation within the three-dimensional culture and wash out and remove cells released from the matrix so that they will not stick to the walls of the vessel and grow to confluence.
  • the released microenviromental cells can be collected and crypreserved for future use.
  • Hepatocytes from any species can be used in the described three-dimensional liver tissue culture system.
  • hepatocytes are human, primate, bear, cow, dog, rodent, pig or turkey hepatocytes.
  • hepatocytes are bear hepatocytes.
  • bear hepatocytes are from American black bear (Ursus Americanus), Asiatic black bear (Selenarctos thibetanus), polar bear (Ursus ma ⁇ timus), brown bear ⁇ Ursus arctos), sun bear ⁇ Helarctosjnalayanus), giant panda
  • LAI-2875394v7 Alluropoda melanoleuca
  • sloth bear Melursus ursinus
  • spectacled bear Temarctus ornatns
  • Hepatocytes can be isolated by conventional methods (see, e.g. , Berry and Friend, 1969, J. Cell Biol. 43:506- 520) which can be adapted for bear liver biopsy or autopsy material. Briefly, a cannula is introduced into the portal vein or a portal branch, and the liver is perfused with calcium-free or magnesium-free buffer until the tissue appears pale. The organ is then perfused with a proteolytic enzyme, such as a collagenase solution at an adequate flow rate to digest the connective tissue framework. The liver is then washed in buffer and the cells are dispersed. The cell suspension can be filtered through a 70 ⁇ m nylon mesh to remove debris.
  • a proteolytic enzyme such as a collagenase solution
  • Hepatocytes can be selected from the cell suspension by various established methods including differential centrifugation against various gradients [0087]
  • HEPES buffer For perfusion of individual lobes of excised bear liver, HEPES buffer can be used. Perfusion of collagenase in HEPES buffer can be accomplished at the rate of about 10, 20, 30, 40, 50, 75, 100, 150 or 200 ml/minute. A single cell suspension is obtained after perfusion with a single type of collagenase, mixed with collagneases, collagenase/dispase, collagenase/pronase or other enzyme mixture for 20 minutes at 37 0 C.
  • the isolated hepatocytes can then be used to inoculate the three-dimensional microenviromental tissue.
  • Hepatocytes function in vitro can be maintained over longer time periods if they are cultured with various ECM substances or co-cultured with other microenviromental cell types, although cellular proliferation is low or absent in these systems after the first several days of culture (Michalopoulos et al., 1975, Exp. Cell Res. 94:70-78; Dunn e/ ⁇ /., 1989, FASEB J. 3:174-177; Reid e/ ⁇ /., 1980, Ann. N. Y. Acad. Sci. 349:70-76; Bissell et al., 1987, J. Clin. Invest.
  • three-dimensional frameworks such as the nylon screens, not only provide an increased surface area for cell growth but apparently allow hepatocytes and microenviromental cells to form a microenvironment conducive to expression of liver-
  • Hepatocytes that are inoculated onto a three-dimensional framework containing the various types of liver microenviromental cells self assemble into liver-specific structures and form various cell- cell interactions including hepatocytes-Kupffer cell, hepatocytes-vascular endothelial cell, PC-biliary endothelial cell, PC-stellate cell, PC-adipoctyes as well as the various combinations of microenviromental cells.
  • Contiguous hepatocytes form bile canaliculi into which they synthesize bile acids, albumin, fibrinogen, transferrin and other proteins are released basolaternall into the medium.
  • Hepatocytes display cP450 metabolism, including induction and inhibition for > two month in culture. Growth of hepatocytes is evident in association with these microenviromental cell and can proceed until all available space for expansion within the framework is exhausted. Albumin secretion by hepatocytes increases by >700% over 'time zero' levels by 24 days of co-culture (0.66 ⁇ 0.32 vs. 5.5 ⁇ 0.70 ⁇ g/ml; P ⁇ O.01) and although the levels drop thereafter, they remain about 400% greater than input levels at 48 days of co-culture (0.66 ⁇ 0.32 vs. 3.28 ⁇ 0.59 ⁇ g/ml; P ⁇ O.025).
  • the three-dimensional culture system of the present invention maximizes cell-cell contact which enhances hepatocyte protein synthesis in vitro.
  • Hepatocyte proliferation can be difficult to quantify in co-cultures because of the presence of other cell types, hepatocyte growth is evident in histological sections through the three-dimensional cultures. Hepatocytes are the largest cells of the co- culture and unlike stroma, which are irregularly-shaped and branched cells, are round.
  • hepatocytes express this protein following hepatotoxic injury (Araki et al, 1992, Acta Anat. 143: 169-177) or in response to perturbations in plasma proteins associated with nephrotic syndrome (Maurice et al, 1979, Lab. Invest. 40:39-45). It is possible that initially, most hepatocytes inoculated onto the nylon screen/microenviromental tissue synthesize albumin and that this model, in some respects, resembles regenerating or injured liver. As hepatocytes fill the framework, their proliferation rate slows, and albumin as well as fibronectin synthesis decline in the majority of the cells, presumably because of ECM or other microenviromental factors.
  • ECM substances influence cell division and gene expression in hepatic cells (Michalopoulos et al, 1979, In vitro 15:796-805; Bernuau et al, 1981, Biol. Cell 40:17-22) and albumin synthesis in cultured hepatocytes can be induced by certain ECM proteins (Michalopoulos et al, 1979, In vitro 15:796-805; Monomer et al, 1987, J. Cell Physiol. 130:221-227).
  • hepatocytes functional heterogeneity has been described by a number of investigators and purportedly is influenced by several factors including: blood gas and
  • LAI-2875394v7 nutrient gradients across the acinus (Matsumara et al , 1983, Amer. J. Physiol. 244:G656- 659), microenviromental differences (Martinez-Hernandez et al, 1993, In: Extracellular Matrix:Chemistry, Biology, Pathology, Zern and Reid, Eds. Marcel-Dekker, N. Y.), and maturational gradients of hepatocytes from the portal region (immature) to the terminal hepatic vein (mature) (Arber et al, 1988, Liver 8:80-87).
  • the cultures of the present invention display a number of liver-specific functions for up to 7 weeks in culture, including TCDD-inducible cP450 enzyme activity. Although the three populations of hepatic cells that are resolved by flow cytometry all exhibit some ability to convert EFEE to fluorescein, and the highest activity is observed in the hepatocytes populations. [0093]
  • the characteristics of cell growth on three-dimensional frameworks are intrinsically different from that on flat-bottomed plastic flasks. For example, the cell matrix deposition is enhanced, but proliferation rate is lower when microenviromental cells are cultured on nylon screens as compared to plastic flasks.
  • This three-dimensional framework can also enhance the opportunity for normal cell-cell interactions and orientation, thereby permitting the various subpopulations of cells to act deterministically to form a tissue-like construct.
  • the presence of inhibitors in serum has been hypothesized as a potential reason why hepatocytes fail to proliferate in culture (Barnes and Sato, 1980, Cell 22:649-655) and serum factors have been reported to contribute to the appearance of the large, playful, and putatively de-differentiated masses of hepatocytes in monolayer cultures (Grisham, 1980, Ann. N.Y. Acad. Sci. 349:128-137; Hayner et al, 1988, Cancer Res. 48:368-378).
  • liver cultures disclosed herein are fed with SFM in order to eliminate nonspecific protein binding for ELISA assays but this medium lacks sufficient nutrients to maintain the cells for long term.
  • SFM most obvious deficiency of this SFM is its inability to support microenviromental cells, which begin to die after about 48 h, an effect which is ameliorated but not completely abrogated by hydrocortisone supplementation.
  • PGA single fibers arranged into a felt are used in the working examples since it almost entirely degrades by 30 days in situ (Naughton et al, 1994, Hematol. Rev. 8:37-49).
  • constructs containing fiber bundles are found to persist for substantially longer periods. Fibroblastic compartmentalization of these constructs in vivo presents a tangible problem; connective tissue accumulation around the graft site can inhibit the movement of metabolites, thereby limiting the functional life of the graft (Naughton et al, 1992, Somat. Cell MoI. Gen. 18:451-462).
  • the survival and function of grafts of hepatic PC:microenviromental cell co-cultures on PGA felt at various implantation sites in rats indicate that these constructs can be surgically implanted as tissue equivalents.
  • hepatic structures such as sinusoids and ductules implies that the cells are deterministic with respect to their formation of these structures; if all cell types that are normally present in a tissue are present in the culture/graft, they will re-establish their 'normal' orientation in vivo.
  • the present invention also discloses the successful graft of liver tissue that is cultured in vitro.
  • the three-dimensional liver cell culture system should be suspended in the nutrient medium. Cultures should be fed with fresh media periodically. Again, care should be taken to prevent cells released from the culture from sticking to the walls of the vessel where they could proliferate and form a confluent monolayer. The release of cells from the three-dimensional culture appears to occur more readily when culturing tissues, such as liver or bone marrow as opposed to structural tissues. As previously explained, should the released cells stick to the culture vessel and form a confluent monolayer, the proliferation of the three-dimensional culture can be 'shut down'.
  • Growth factors and regulatory factors can be, but need not be added to the media since these types of factors are elaborated by the three-dimensional microenviromental cells. However, the addition of such factors, or the inoculation of other specialized cells can be used to enhance, alter or modulate proliferation and cell maturation in the cultures.
  • the growth and activity of cells in culture can be affected by a variety of growth factors, such as insulin, growth hormone, somatomedins, colony stimulating factors, erythropoietin,
  • LAI-2875394v7 epidermal growth factor hepatic erythropoietic factor (hepatopoietin), and liver-cell growth factor.
  • Other factors which regulate proliferation and/or differentiation include prostaglandins, interleukins, and naturally-occurring chalones.
  • Agents that increase the synthesis or formation of bile acids, particularly UDCA can be added to the media.
  • agents include, but are not limited to, taurine, ⁇ -glucan, deuterium, glucocorticoid, dexamethasone, probucol, alpha-tocopherol, estradiol, progesterone, triidothyronine. See, e.g., Prince et ctl., 1989, Biochem J. 15(262):341-48; Lakeev et al, 1993, Biokhimiia 58(3):406-15; Chico et al, 1996, Exp. Clin. Endocrinol. Diabetes. 104(2): 137-44; Ellis et al, 1998, Hepatology 27(2):615-20.
  • the three-dimensional culture system can be used in vitro to produce one or more biologically active molecules in high yield.
  • a cell which naturally produces large quantities of a particular biological product ⁇ e.g., a bile acid, a growth factor, regulatory factor, peptide hormone, antibody, etc.
  • a host cell genetically engineered to produce a foreign gene product could be clonally expanded using the three-dimensional culture system in vitro.
  • the biologically active molecule is a bile acid, or its derivative, salt or conjugate or combination thereof.
  • the biologically active molecule is ursodeoxycholic acid ('UDCA') or its salt, conjugate or combination thereof.
  • the conditioned medium can be used or the molecule can be readily isolated from the conditioned medium using standard separation techniques (e.g., HPLC, column chromatography, electrophoretic techniques).
  • a 'bioreactor' can be used to take advantage of the continuous flow method for feeding the three-dimensional cultures in vitro. Essentially, as fresh media is passed through the three-dimensional culture, the molecule will be washed out of the culture along with the cells released from the culture.
  • the biologically active molecule could be isolated (e.g., by HPLC column chromatography, electrophoresis, etc.) from the outflow of spent or conditioned media.
  • the cells can be cultured by any means known in the art.
  • the cells are cultured in an environment which enables aseptic processing and handling, continuous
  • LAI-2875394v7 feeding cells and collecting media, or large scale growth The media can be conditioned using, for example, an apparatus for cell culturing like that described in U.S. Pat. Nos. 5,763,267; 5,792,603, 5,827,729; 5,843,776, 5,846,828, 6,008,049, 6,060,306, 6,121 ,042, and 6,218,182, the disclosures of which are incorporated herein by reference. [00101]
  • the three-dimensional cell and tissue is cultured using an apparatus, such as described in U.S. Pat. Nos. 5,827,729, 6,008,049, 6,218,182, the contents of which are incorporated by references in their entireties.
  • the system is provided with a bioreactor that has a tissue disposed between two media flows.
  • the tissue is cultured on a porous substrate.
  • a first media flow having a first concentration of solutes is in direct contact with one side of the tissue, and a second media flow having a second concentration of solutes is in direct contact with the opposing side of the tissue.
  • the first concentration of solutes is different than the second concentration of solutes, creating a diffusional or osmotic pressure gradient which causes movement of solutes, including nutrients, through the tissue.
  • the media flows can also be used to supply gases and growth factors to the cells in varying concentrations, depending on the needs of the particular tissue being cultured. Metabolic waste products, including carbon dioxide, are secreted into the media flows and carried away.
  • the three-dimensional cell and tissue is cultured in a manner allowing for large scale growth (yielding large scale conditioned media) using, for example, an apparatus for aseptic large scale culturing like that described in U.S. Pat. No. 5,763,267 (the '267 patent), which is incorporated by reference herein in its entirety.
  • an apparatus for aseptic large scale culturing like that described in U.S. Pat. No. 5,763,267 (the '267 patent), which is incorporated by reference herein in its entirety.
  • preconditioned culture media is transported from a fluid reservoir to an inlet manifold and evenly distributed to the cultures in a continuous flow system and is useful in culturing three-dimensional cell and tissue cultures, such as live cell cultures, for example.
  • the apparatus described in the '267 patent includes a plurality of flexible or semi-flexible treatment chambers comprising one or more individual culture pockets, a plurality of rigid spacers, an inlet fluid manifold, an outlet fluid manifold, a fluid reservoir, and a means for transporting fluid within the system.
  • LAI-2875394v7 [00103) During treatment, liquid medium is transported from the fluid reservoir to the inlet manifold, which in turn evenly distributes the media to each of the connected treatment chambers and internal culture pockets.
  • An outlet fluid manifold is also provided to ensure that each treatment chamber is evenly filled and to ensure that any air bubbles formed during treatment are removed from the treatment chambers.
  • the treatment chambers are flexible or semi-flexible so as to provide for easy end-user handling during rinsing and application of the cultured transplants. Due to the flexibility of the treatment chambers, rigid spacers are also provided which ensure even fluid distribution within the chambers during treatment.
  • the 'conditioned' medium is pumped out of the system and processed for use.
  • the conditioned cell medium is harvested from the apparatus at the later stages of growth of the tissue when the level of certain growth factors and connective tissue protein secretion is at its highest level.
  • the medium conditioned by the three- dimensional cell culture is collected after exposure of the medium to the cells, for example, periodically at day 1 through day 14 of culturing.
  • the three-dimensional tissue is cultivated in an apparatus for aseptic growth of three-dimensional tissue cultures as described in U.S. Pat. No. 5,843,766 (the '766 patent), incorporated herein in its entirety.
  • the '766 patent discloses a tissue culture chamber in which the chamber is a casing that provides for growth of three- dimensional tissue that can be grown, preserved in frozen form, and shipped to the end user in the same aseptic container.
  • the tissue culture chamber includes a casing comprising a substrate within the casing designed to facilitate three-dimensional tissue growth on the surface of the substrate.
  • the casing includes an inlet and an outlet port which assist the inflow and outflow of medium.
  • the casing also includes at least one flow distributor.
  • the flow distributor is a baffle, which is used to distribute the flow of the medium within the chamber to create a continuous, uniform piece of three-dimensional tissue.
  • the flow distributor is a combination of deflector plates, distribution channels, and a flow channel.
  • the casing further includes a seal so as to ensure an aseptic environment inside the chamber during tissue growth and storage. Again the medium is preferably harvested from the apparatus at the later stages of
  • the medium conditioned by the three-dimensional cell culture is collected after exposure of the medium to the cells at days 1 through day 14 of culturing.
  • the cell medium can be used in any state.
  • Physical embodiments of the conditioned medium include, but are not limited to, liquid or solid, frozen, lyophilized or otherwise dried into a powder.
  • the medium can be formulated with a pharmaceutically acceptable carrier as a vehicle for internal administration, applied directly to a food item or product, formulated with a salve or ointment for topical applications, or, for example, made into or added to surgical glue to accelerate healing of sutures following invasive procedures.
  • processing can include, but is not limited to, concentration by a water flux filtration device or by defiltration using the methods described, e.g., in Doyle et ah, Cell &Tissue Culture. Laboratory Procedures in Biochemistry (1 st Ed., 1994) John Wiley and Sons, pp 29 D:0.1 29 D:0.4.
  • the medium can be concentrated, e.g., 10-fold to 20-fold using a positive pressure concentration device having a filter with a 10,000 ml cut-off (Amicon, Beverly, MA.).
  • the conditioned medium can be further processed for removing undesirable components, such as protease and for isolation of a biologically active molecule of interest.
  • the methods used for isolation and purification of biologically active molecules are such that the optimal biological activity is maintained, and will be readily apparent to one of ordinary skill in the art.
  • Exemplary methods include, but are not limited to, gel chromatography (using matrices, such as sephadex) ion exchange, metal chelate affinity chromatography with an insoluble matrix, such as cross-linked agarose, HPLC purification and hydrophobic interaction chromatography of the conditioned media.
  • gel chromatography using matrices, such as sephadex
  • metal chelate affinity chromatography with an insoluble matrix such as cross-linked agarose
  • HPLC purification and hydrophobic interaction chromatography of the conditioned media Such techniques are described in greater detail, e.g., in Doyle et ah, Cell &Tissue Culture. Laboratory Procedures in Biochemistry (1 st Ed., 1994
  • L ⁇ I-2875394v7 upon the desired application of the conditioned medium, and/or products derived thereof, appropriate measures must be taken to maintain sterility.
  • sterilization can be necessary and can be accomplished by methods known to one of ordinary skill in the art, such as, for example, heat and/or filter sterilization taking care to preserve the desired biological activity.
  • the biologically active molecule can be isolated from the collected culture medium by any method or technique according to the judgment of those of skill in the art.
  • bile acid synthesis and formation in cell culture medium can be measured by any methods known to those of skill in the art, including, but not limited to, capillary gas- liquid chromatography, enzymatic-bioluminescence assay, gas chromatography-mass spectrometry, anion exchange chromatography.
  • capillary gas- liquid chromatography enzymatic-bioluminescence assay
  • gas chromatography-mass spectrometry anion exchange chromatography.
  • Biological activities of molecules can be measured by any methods known in the art.
  • the effect of bile acids on limiting cell apoptosis can be measured, e.g., as described in detail in U.S. Pat. No. 6,544,972, the contents of which is incorporated by reference in its entirety.
  • the present invention provides a composition comprising a biologically active molecule produced by a three-dimensional cell and tissue culture system as described above.
  • the composition of the invention can be the conditioned medium itself, an extract, subset or concentrate of the conditioned medium, a combination of the conditioned medium and an appropriate carrier, or a composition comprising a biologically active molecule isolated from the conditioned medium.
  • the biologically active molecule is a bile acid, or its derivative, salt or conjugate thereof.
  • the bile acid can be any bile acid known in the art, including, but not limited to, deoxycholic acid, cholic acid, taurocholic acid, glycocholic acid, glycodeoxycholic acid, taurodeoxycholic acid, ursodeoxycholic acid and/orchenodeoxycholic acid.
  • ⁇ bile acid conjugate is a bile acid in which a substituent (e g . gly cine, taurine, glucuronate, sulfate or other substituent) is attached to the side chain of carboxylic acid or to one of the ring hydroxyl groups via an ester, ether, or amide linkage.
  • a substituent e g . gly cine, taurine, glucuronate, sulfate or other substituent
  • the biologically active molecule is ursodeoxycholic acid (UDCA) or its derivative, salt or conjugate thereof.
  • the biologically active molecule is a UDCA conjugate, such as its taurine conjugate, TUDCA.
  • the composition comprises more than 5%, 10%, 25%, 50%, 75%, 90%, 95% or 99% (w/v) of the biologically active molecule, such as a bile acid (e.g., UDCA or TUDCA).
  • compositions comprising a biologically active molecule derived from a conditioned culture medium using a three- dimensional cell and tissue culture system.
  • compositions of the invention can be used as food additives and/or formulated into dietary supplements.
  • the conditioned media of the invention contains many useful biologically active molecules in an abundance and variety not found in individual foods or food groups.
  • the composition can be sterile and free from contamination by human pathogens (i.e. , aseptic).
  • the composition can be concentrated and/or lyophilized and preferably administered in capsules or tablets for ingestion. Alternatively, the compositions can be directly added to adult or baby food to enhance nutritional content or to reduce blood lipid or cholesterol levels.
  • compositions are used for pharmaceutical applications for treating a disease or condition, such as by alleviating one or more symptoms of the disease or condition, in subject in need thereof.
  • the present invention provides a method for treating a disease or condition in subject in need thereof comprising administering an effective amount of a composition produced by the method described herein.
  • the diseases or conditions include but are limited to liver or gallbladder diseases, diseases relating to lipid or cholesterol hemeostasis, degenerative diseases or disorders, cardiovascular or cerebrovascular diseases or inflammatory diseases.
  • compositions of the present invention are used for the treatment of various liver or gallbladder diseases, or a symptom thereof.
  • Liver or gallbladder disorders include but are limited to cholestasis disease, gallstone or choleliths, cirrhosis, primarily biliary cirrhosis, sclerosing cholangitis, steatoheptitis, biliary atresia, hepatitis, jaundice, intrahepatic cholestatsis of preganancy, cystic fibrosis-associated liver disease, chronic graft- versus host disease of the liver or cholestatic diseases.
  • Bile acids also play an important role in regulating cholesterol homeostasis and lipid hemeostasis.
  • the compositions of the present invention are used in the treatment of diseases relating to lipid or cholesterol hemeostasis.
  • diseases include, but are not limited to, dyslipidemia (e.g., hyperlipidemia) or dyscholesterolemia (e.g., hypercholesterolemia).
  • Mitochondrial dysfunction and subsequent oxidative damage have been implicated in the pathogenesis of several neurobiological disorders, such as ischemic neuronal injury and chronic neurodegenerative disease. See, e.g., Nathanson et al., 1991,
  • the compositions of the present invention are used in inhibiting apoptosis of a mammalian cell comprising contacting the cell with an effective amount of the composition produced by the methods described herein.
  • the apoptosis can be induced by a nonmembrane damaging agent, e.g., TGF ⁇ l , anti-Fas antibody and okadaic acid.
  • compositions of the present invention are used in the treatment of a disease or condition associated with increased levels of apoptosis as a pathogenesis of the disorder.
  • diseases or conditions include, but are not limited to, degenerative, cardiovascular or cerebrovascular diseases, or injuries of the nervous system.
  • degenerative diseases include, but are not limited to, glaucoma, Huntington's disease, Parkinson's disease, Alzheimer's disease, retinal degeneration.
  • Cardiovascular or cerebrovascular diseases include, but are not limited to, stroke, myocardial infarction, atherosclerosis.
  • compositions of the present invention are used to treat injuries of the nervous system associated with hemorrhage, for example, a hemorrhagic stroke, a head trauma, a spinal cord injury or a peripheral nerve injury.
  • the compositions of the present invention are used to alleviate spasms and delirium caused by extensive burns, reduce swelling, inflammation and pain in trauma, sprains, fractures or hemorrhoids.
  • compositions of the present invention comprise a pharmaceutically acceptable carrier.
  • pharmaceutically acceptable means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans.
  • the term 'carrier' refers to a diluent, adjuvant (e.g. , Freund's adjuvant (complete and incomplete)), excipient, or vehicle with which the therapeutic is administered.
  • Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water is a preferred carrier when the
  • LAI-2875394v7 pharmaceutical composition is administered intravenously.
  • Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions.
  • suitable pharmaceutical carriers are described, for example, in Remington's Pharmaceutical Sciences ( 18 lh Ed., 1995). [00130J Typical pharmaceutical compositions and dosage forms comprise one or more excipients.
  • Suitable excipients are well-known to those skilled in the art of pharmacy, and non-limiting examples of suitable excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. Whether a particular excipient is suitable for incorporation into a pharmaceutical composition or dosage form depends on a variety of factors well known in the art including, but not limited to, the way in which the dosage form will be administered to a patient and the specific active ingredients in the dosage form.
  • the composition or single unit dosage form if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents.
  • Lactose-free compositions of the invention can comprise excipients that are well known in the art and are listed, for example, in the U.S. Pharmocopia (USP) SP (XXI)/NF (XVI).
  • USP U.S. Pharmocopia
  • XXI U.S. Pharmocopia
  • NF NF
  • lactose-free compositions comprise an active ingredient, a binder/filler, and a lubricant in pharmaceutically compatible and pharmaceutically acceptable amounts.
  • Exemplary lactose-free dosage forms comprise an active ingredient, microcrystalline cellulose, pre-gelatinized starch, and magnesium stearate
  • composition can be formulated into pharmaceuticals in the form of tablets, capsules, skin patches, inhalers, eye drops, nose drops, ear drops, suppositories, creams, ointments, injectables, hydrogels and into any other appropriate formulation known to one of skill in the art.
  • compositions can take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable carrier or excipients, such as binding agents (e.g., pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrants (e.g., potato starch or sodium starch glycolae); or wetting agents (e.g., sodium lauryl sulphate). Tablets can be coated using pharmaceutically acceptable carrier or excipients, such as binding agents (e.g., pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g., magnesium stearate, talc or si
  • Liquid preparations for oral administration can take the form of, for example, solutions, syrups or suspensions, or they can be presented as a dry product for constitution with water or other suitable vehicle before use.
  • Such liquid preparations can be prepared by conventional means with pharmaceutically acceptable additives, such as suspending agents (e.g., sorbitol syrup cellulose derivatives or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g. , almond oil, oily esters, ethyl alcohol or fractionated vegetable oils); and preservatives (e.g., methyl or propyl-p-hydroxybenzoates or sorbic acid).
  • suspending agents e.g., sorbitol syrup cellulose derivatives or hydrogenated edible fats
  • emulsifying agents e.g., lecithin or acacia
  • non-aqueous vehicles e.g. , almond oil, oily esters, eth
  • compositions of the invention can be delivered to a patient via a variety of routes using standard procedures well known to those of skill in the art. For example, such delivery can be site-specific, oral, nasal, intravenous, subcutaneous, intradermal, transdermal, intramuscular or intraperitoneal administration. Also, they can be formulated to function as controlled, slow release vehicles.
  • the therapeutically effective doses of any of the biologically active molecules can routinely be determined using techniques well known to those of skill in the art. See, e.g., Physician's Desk Reference (59 th Ed., 2005), Thomas Healthcare; Remington's Pharmaceutical Sciences (18 th Ed., 1995) Mack Publishing Co., Easton, PA; Goodman & Gilman's The Pharmacological Basis of Therapeutics (1 1 th Ed., 2005), McGraw Hill Professional.
  • a 'therapeutically effective' dose refers to that amount of the compound sufficient to result in amelioration of at least one symptom of the processes and/or diseases being treated.
  • the data obtained from the cell culture assays and animal studies can be used in formulating a range of dosage for use in humans.
  • the dosage of such compounds lies preferably within a range of circulating concentrations that include the ED 50 with little or no toxicity.
  • the dosage can vary within this range depending upon the dosage form employed and the route of administration utilized. For any compound used in the method of the
  • the therapeutically effective dose can be estimated initially from cell culture assays.
  • a circulating plasma concentration range that includes the IC 50 ⁇ i.e., the concentration of the test compound which achieves a half-maximal inhibition of symptoms) as determined in cell culture.
  • IC 50 i.e., the concentration of the test compound which achieves a half-maximal inhibition of symptoms
  • levels in plasma can be measured, for example, by high performance liquid chromatography.
  • Hepatic cells were separated into various subpopulations using either a two-step 'PERCOLL' gradient centrifugation (Naughton et al., 1991, In: In vitro Toxicology, Vol. 8, Mechanisms and New Technology, Mary Ann Liebert, Inc., New York) or a pre-formed continuous gradient.
  • 'PERCOLL' stock solution was diluted to 70% (v/v) with IX Dulbecco's phosphate buffered saline (DPBS).
  • DPBS IX Dulbecco's phosphate buffered saline
  • the cell suspension was overlaid and spun at 1200 x g for 15 min at 10° C. in an IEC swing bucket centrifuge to remove cellular debris and erythrocytes. The remaining cells were resuspended in DPBS and layered atop a 25% : 50% discontinuous 'PERCOLL' gradient and centrifuged as in the first step.
  • a 30% 'PERCOLL' solution was spun at 30,000Xg for 30 min in a Sorvall RCB5 centrifuge with a 20° fixed angle rotor to form a continuous gradient. Suspensions of hepatic cells were overlaid and centrifuged at 200Xg for 15 min at 10° C. The densities of the various isolation zones were
  • LAI-2875394v7 and cytosmear preparations of cells of each zone were stained with DIFF-QUIK (Baxter, IL).
  • Screen cultures were placed in slide chambers, inoculated with 2-5X10 hepatic hepatocytes or acidophilic reserve cells, and transferred to 25 cm 2 flasks after 18-24 h.
  • Cells were cultured (5% CO 2 /35°-37°C./>90% humidity) in DMEM conditioned with 6% FBS and 10% equine serum and supplemented with 10 ng/ml glucagon, 10 ⁇ g/ml insulin (Sigma Chem. Co., MO), 10 ⁇ g/ml glucose, and 10 '7 M hydrocortisone hemisuccinate. Complete medium replacement was performed 4-5 times per week.
  • Bile acids from the liver cell culture can be analyzed by any method known in the art, for example, as described in Einarsson et al, 2000, World J. Gastroentero. 6(4): 522-525; Ellis et al, 1998, Hepatology 27:615-620. Briefly, deuterium-labeled bile acids are added to the collected culture medium. The medium, together with internal standards, is diluted with aqueous ethanol (1/1 vol/vol) and hydrolyzed at 125 0 C for 12 hours using potassium hydroxide (1 mol/1). The hydrolyzed mixture is diluted with saline and extracted with ether. The ether phase is washed with water until neutral.
  • the solvent is evaporated and the residue is methylated with diazomethane.
  • the methylated extract is then converted into trimethysilyl ether derivatives with hexamethyl-silazane and tricholrosilane and further analyzed by gas chromatography/mass spectrometry.
  • LAI-2875394v7 for 12-14 h.
  • the wells were washed with 0.05% Tween-20 in PBS and non-specific binding sites were blocked with 5.0% bovine serum albumin (BSA)(Miles Inc., IL) in PBS.
  • BSA bovine serum albumin
  • 100 ⁇ l of peroxidase-conjugated sheep anti-rat albumin was added to each well and incubated for 1 hr at 22° C.
  • the wells were washed with 0.05% Tween-20 and incubated for 15 min with O-phenylenediamine substrate.
  • the reaction was stopped and absorbance at 490 run was measured with a kinetic microplate reader (Molecular Devices Inc., CA). Results were calculated from a standard curve constructed using chromatographically-pure rat albumin.
  • SFM serum-free medium
  • the SFM formulation of Enat et al (Enat ⁇ t al. , 1984, Proc. Nat. Acad. Sci. USA 81 : 141 1 - 1415) was modified by supplementing with hydrocortisone hemisuccinate (50 ⁇ g/ml), fungizone (0.5 ⁇ g/ml), penicillin (5 U/ml), and streptomycin (5 ⁇ g/ml).
  • L ⁇ I-2875394v7 samples wore analyzed using an EPICS C flow cytometer (Coulter Electronics, FL) tuned to a wavelength of 488 nm w ith the fluorescence gain adjusted to exclude >98% of the control cells.
  • Windows were established around the various cell populations using the forward light scatter (FLS) vs. side scatter (SS) two parameter histogram and the percentage of positively fluorescent events was determined.
  • FLS forward light scatter
  • SS side scatter
  • Cytochrome P-450 (cP450 ) assay Cells were analyzed for evidence to cP450 enzyme activity by quantifying incremental fluorescein fluorescence in cells accumulating ethoxyfluorescein ethyl ester (EFEE) (Miller, 1983, Anal. Chem. 133:46-57; White et al, 1987, Biochem. J. 247:23-28). EFEE to fluorescein conversion occurs via the specific cleavage of an ether linkage by a polycyclic aromatic hydrocarbon (PAH)-induced cP450 (Miller,, 1983, Anal. Chem. 133:46-57).
  • PAH polycyclic aromatic hydrocarbon
  • EFEE metabolism requires NADPH, and can be inhibited by carbon monoxide or monoclonal antibodies that decrease PAH or benzo(a)pyrene metabolism (Miller., 1983, Anal. Chem. 133:46-57).
  • TCDD 2,3,7,8-tetrachlorodibenzo-p-dioxin
  • DMSO dimethylsulfoxide
  • Cultured cells were lifted using a dispase- collagenase mixture, pelleted and resuspended in phosphate buffered saline (PBS) at a density of .about.5 XlO 5 cells/ml, stored on ice for 1 h, and gradually warmed to 37° C.
  • Cells were incubated with 50 nM EFEE (Molecular Probes, OR) in PBS for 5 min at 37° C. and examined for green fluorescence on a flow cytometer with a 515 nm long-pass filter and tuned to the 488 nm band. Fluorescence resulting from EFEE to fluorescein conversion was gated on various populations of cells based on differences in FLS vs.
  • PBS phosphate buffered saline
  • Total non-adherent and adherent zone cell counts were determined using a Coulter Model ZM cell counter. Differential cell counts were based strictly on the morphology of cells stained using Diff-Quik (Baxter SP, IL). Phagocytosis of colloidal carbon and reaction with FITC-conjugated antibodies to the vW factor VIII segment were used initially to identify Kupffer cells and vascular endothelial cells, respectively.
  • Enzyme digested serial sections also were reacted with monoclonal antibodies to rat cytokeratin 19 (Chemicon International Inc., CA) for 90 min at 37° C, washed, and incubated with sheep anti-mouse IgG-FITC for 30 min. Photographs were obtained using a Nikon Optiphot fluorescence microscope. 7.2 RESULTS
  • T) pe I These were small (15-20 ⁇ m) mononuclear hepatocytes with deep cytoplasmic basophilia. These were relatively dense, attached poorly to preestablished microenviromental cells and did not adhere directly to plastic, and did not proliferate in vitro in association with either substratum.
  • Type II These were moderately sized (20-30 ⁇ m) binuclear cells with 1-2 nucleoli and moderate to deep cytoplasmic basophilia (FIG. IA). Some of these cells adhered to plastic and some Type I hepatocytes attached to them. They proliferated for 2-3 days after plating in monolayer culture and then became mitotically inactive.
  • Type III These large (>35 ⁇ m), ghost-like cells (FIG. 1 B) were usually binuclear with 2-3 very prominent nucleoli per nucleus, accumulated little or no basic stain in the cytoplasm and displayed buoyant densities similar to hepatic microenviromental cells although their volume was substantially greater than these cells.
  • L ⁇ I-2875394v7 microenviromental cells as compared to hepatocytes permitted a relatively simple differentiation of these cell types.
  • the individual subpopulations of liver microenviromental cells were less distinct from each other based purely on morphological parameters.
  • fibroblasts and adipocytes were identified morphologically
  • Kupffer cells and endothelial cells were differentiated by their ability to phagocytose colloidal carbon or be recognized by a monoclonal antibody to vW factor, respectively.
  • Moderate levels of MHC I antigens were detected on all of these microenviromental cell subsets; Kupffer cells and endothelia were the only stroma to express MHC II antigens.
  • FIG. 2A When hepatocytes were inoculated onto nylon screens containing preestablished microenviromental cells, they grew in clusters for the first 1-2 weeks of culture (FIG. 2A); patterns of cell growth were increasingly more difficult to discern after this time because of the high cell density of the framework.
  • the screen itself was composed of nylon fibers that were 90 ⁇ m in diameter and arranged into a square weave pattern with openings of 140 ⁇ mX140 ⁇ m. The total volume for cell growth within each of these spaces was .about.1.8 m 3 .
  • Microenviromental cells and their processes are the major elements of the field at several hours after the inoculation of the microenviromental tissue with hepatocytes (FIG. 2B). With time the hepatocytes eventually filled in most of the available spaces seen in this section.
  • the section of a 52 day old culture (FIG. 2C) shows a screen space that is tightly packed with large, round PC. The process of filling in this framework was generally complete by 4-6 weeks of co-culture.
  • hepatocytes in the suspended nylon screen co-cultures displayed a rounded, as compared to the spread/flat morphology that was typical of hepatocyte culture on plastic flasks.
  • These round cells stained positively for albumin using the immunoperoxidase method (FIG. 4A) and for fibrinogen, transferrin, and fibronectin by immunofluorescence. They also stained positively for cytokeratin 19, an epithelial cell marker found on hepatocytes (FlG. 4B).
  • Hepatocytes derived from suspended nylon screen co-cultures displayed TCDD- inducible cP450 enzyme activity for up to 56 days as indicated by their ability to transform EFEE to fluorescein (FIG. 5A and 5B). Since the flow cytometer was gated on discrete populations of cells based upon their physical characteristics (FLS vs. SS), the EFEE to fluorescein conversion was quantified at the cellular level and leakage of fluorescein from the cell to the medium did not influence this measurement. Peak EFEE to fluorescein conversion was >2 times higher in the 17, 26, 41, or 58 day co-cultures than in either freshly
  • Formation of bile acids in the culture medium can be determined, by anion exchange chromatography and gas chromatography-mass spectrometry, such as described in Einarsson et cil. 2000, World J. Gastroentero 6(4):522-25, the contents of which are
  • LAI-2875394v7 incorporated by reference in its entirety.
  • Deuterium-labeled bile acids can be added to the collected culture medium. Alter alkaline hydrolysis and extraction using acidic ether, the bile acids are analyzed by gas chromatography-mass spectrometry.
  • compositions comprising UDCA or TUDCA on cell apoptosis can assessed, e.g., using the method described in U.S. Pat. No. 6,544,972, the content of which is incorporated by reference in its entirety. Briefly, Huh-7 cells, HepG2 cells or primary rat hepatocytes can be cultured and incubated with the composition produced in the above example for 2 hours. Then the cell can be treated with TGF- ⁇ l, 50 nM okadaic acid (Boehringer Mannheim Biochemicals, Inc, Indianapolis, Ind.), Fas ligand, or no addition for 48 h.
  • TGF- ⁇ l 50 nM okadaic acid
  • Fas ligand Fas ligand

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Abstract

The present invention provides to a method tor producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, such as ursodeoxycholic acid, using a three-dimensional culture system. The culture system described herein is closely approximates what is found in vivo and provides for proliferation and appropriate liver cell maturation to produce biologically active molecules, such as bile acids. The present invention also provides a composition produced by the method described herein.

Description

COMPOSITIONS AND METHODS OF PRODUCING URSODEOXYCHOLIC ACID
1. FIELD OF INVENTION
[0001] The present invention relates to a composition comprising a biologically active molecule, such as a bile acid, derived from a three-dimensional cell and tissue culture system. The present invention also relates to a method for the production of a composition comprising a biologically active molecule using this culture system for the long term culture of liver cells and tissues in vitro in an environment that more closely approximates that found in vivo. The culture system described herein provides for proliferation and appropriate liver cell maturation to form structures analogous to tissue counterparts in vivo. The resulting liver tissues survive for prolonged periods, perform liver-specific functions.
2. BACKGROUND OF THE INVENTION
[0002] Bear bile has been used as a traditional medicine in Asia for over 3000 years. In traditional Chinese medicine, bear bile is used to brighten the eyes, cool the heart and liver and eliminate parasites from the body. For example, bear bile has been utilized to treat hepatitis and hepatic coma, alleviate spasms and delirium caused by extensive burns, reduce swelling, inflammation and pain in trauma, sprains, fractures or hemorrhoids. [0003] Due to its beneficial medical effect, there is an increased demand in bear bile products and the global illegal trade in bear parts is estimated at two billion dollars annually. The illegal hunting and trade for bears has endangered the population of seven out of the world's eight bear species. In addition, bear farms have been established in many Asian countries, where bears are confined to small cages and fitted with metal catheters to milk their gallbladders to result in a continual supply of bile. In bear farms, bears suffers trauma and frequently die from illness, injury, infection etc.
[0004] It is believed that the active ingredient in bear bile is ursodeoxycholic acid ('UDCA'), a bile acid naturally occurring in human bile in small quantities. UDCA was first isolated from the gallbladders of polar bears at the beginning of the twentieth century. Bears produce significant amount of UDCA in their gallbladders. Besides bear, UDCA is
- 1 -
LAI-2875394v7 also found at much lower concentration in other species including human and can be extracted from turkey, pig or cow bile.
(OOOSJ UDCA has been chemically synthesized since the 1950s. In the United States, it has been approved for the treatment of dissolve gallstone and primarily biliary cirrhosis. Recently, it has been shown that UDCA or tauroursodeoxycholic acid (TUDCA), a soluble form of UDCA, can inhibit apoptosis of mammalian cells and thus could potentially be used in the treatment of degenerative disorders, e.g., glaucoma, Huntington's disease, Parkinson's disease and Alzheimer's disease.
[0006] Chemical synthesized UDCA is expensive. Bear populations are diminishing and suffering due to illegal hunt and bear farms. In addition, many traditional Chinese medicine patients prefer UDCA from natural sources to synthetic sources. Thus, there is a need in the art for a methods for producing UDCA via natural sources to protect bear populations and meet the increased demand for UDCA. The present invention provides a method for producing a bile acid, such as UDCA, via a three-dimensional liver cell culture.
3. SUMMARY OF THE INVENTION
[0007] In one aspect, the present invention provides a composition comprising a biologically active molecule from a conditioned culture medium that is generated using a three-dimensional culture. In certain embodiments, the biologically active molecule is a bile acid, bile acid derivative, bile acid salt, bile acid conjugate, or any combination thereof. In some embodiments, the biologically active molecule is ursodeoxycholic acid ('UDCA') or its salt, conjugate or combination thereof.
[0008] In another aspect, the present invention provides a method for producing a composition comprising a biologically active molecule, such as a bile acid, from a conditioned culture medium using a three-dimensional cell and tissue culture system. In certain embodiments, the biologically active molecule is a bile acid, or its derivative, salt or conjugate or combination thereof. In some embodiments, the biologically active molecule is ursodeoxycholic acid ('UDCA') or its salt, conjugate or combination thereof. In such embodiments, the method comprises inoculating hepatocytes onto a living microenviromental tissue prepared in vitro, incubating the inoculated living microenviromental tissue in a medium so that the inoculated hepatocytes proliferate in
- 2 -
LAI-2875394v7 culture, and collecting the medium. In certain embodiments, the method further comprising the step of isolating the biologically active molecule from the collected medium. [0009] In some embodiments, hepatocytes are inoculated and grown on a pre- established microenviromental tissue. The microenviromental tissue can comprise microenviromental cells actively growing on a three-dimensional framework. The microenviromental tissue can provide the support, growth factors, and regulatory factors necessary to sustain long-term active proliferation of hepatocytes in culture. When grown in this three-dimensional system, the proliferating cells can mature, segregate properly to form components of liver tissues analogous to counterparts found in vivo and synthesize one or more bile acids or salts, conjugate or combinations thereof that are produced in vivo. The culture medium can then be collected and used in various application as discussed below. Also, the collected culture medium can be further processed to be formulated for its intended use and/or the active biologically active molecule can be concentrated by any method or technique known to those of skill in the art.
[0010] The three-dimensional cell and tissue culture system can be cultured by any methods known in the art. In some embodiments, cells are cultured in a manner allowing for easy and aseptic handing or large scale growth.
[0011] In another aspect, the present invention relates to use of a composition comprising a biologically active molecule from a conditioned culture medium using a three- dimensional cell and tissue culture system. In some embodiments, the compositions of the present invention are used as food additives or dietary supplements. In other embodiments, the compositions are used in pharmaceutical applications for treating a disease or condition, such as by alleviating one or more symptoms of the disease or condition, in subject in need thereof. The diseases or conditions include, but are not limited to, liver or gallbladder disorders, disorders relating to cholesterol or lipid homeostasis, degenerative diseases or disorders, cardiovascular or cerebrovascular diseases, or inflammatory diseases, or any combination thereof.
4. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. IA. A cytosmear depicting type I (mononuclear) and type II (binuclear) hepatocytes stained with DIFF-QUIK and isolated by 'PERCOLL' gradient centrifugation.
- 3 -
LAI-2875394v7 The smaller microenviromental elements (arrows) are distinguished from the hepatocytes by virtue of their size, nuclear configuration, and nuclear staining density. Original magnification= 1 ,000 X.
[0013) FIG. I B. Photomicrograph of a cytosmear of cells from the lower band of the discontinuous 'PERCOLL' interface (acidophilic cells). This preparation was stained with DIFF-QUIK for longer periods than was necessary for other hepatocytes in order to visualize their uneven contours, vacuolation, nucleus, and multiple nucleoli. Original magnifϊcation= 1,000 X.
[0014] FIG. 2A. Inverted phase photomicrograph of an 8 day old co-culture of various hepatic hepatocytes derived from the 70% 'PERCOLL' pellet and hepatic microenviromental cells on a nylon screen framework. The inoculation with this heterogeneous mixture of cells promotes the growth of morphologically distinct clusters. [0015] FIG. 2B. Hematoxylin-eosin (H-E) stained section through a liver cell co- culture 24 hr after inoculation of PC. 1 ,000 X. The semicircular space (arrow) denotes the location of the nylon filament. Several round hepatocytes are associated with stroma (S). [0016] FIG. 2C. H-E stained section through a 52-day old liver cell co-culture. Round hepatocytes fill in all of the available space within the template. n=nylon fiber in cross section.
[0017] FIG. 3A. The relationship between total adherent cell count and radiothymidine incorporation in liver co-culture. Vertical lines through the means indicate ±1 sem. — D— indicates cell count, and —indicates thymidine incorporation.
[0018] FIG. 3B. Mean differential cell counts in liver co-cultures of various ages. --■- - indicates hepatocytes, .-o- indicates microenviromental cells, and --•-- indicates acidophilic cells.
[0019] FIG. 4A. Section through a 30-day liver co-culture stained with an anti-albumin peroxidase method. There is a range of positivity, but albumin expression is highest in the darker cells. The interdigitating microenviromental cells do not express albumin. n=space occupied by a cross sectioned nylon fiber of the screen.
[0020] FIG. 4B. Section through a 30-day liver co-culture stained with an anti- cytokeratin 19. Immunofluorescence of the large, round cells of the section (arrows). 500 X.
- 4 -
LAl-2875394v7 [0021] FIG. 5A. EFEE is converted by cytochrome P450 enzymes to fluorescein.
[0022] FIG. 5B. Cytochrome P450 enzyme activity in hepatic cells 21 hr after the introduction of TCDD. The EFEE to fluorescein conversion reaction is quantified as the product of the percentage of positively fluorescent cells and the peak fluorescence channel number. The number of events measured for each sample is 10,000-20,000.
[0023] FIG. 6. Mean quantities of albumin and transferrin present in the medium at various intervals of culture. Vertical lines through the means=±l sem. —D — quadrature indicates albumin and — •-- indicates transferrin.
[0024] FIG. 7. Mean quantities of fibrinogen and fibronectin present in the medium at various intervals of culture. Vertical lines through the means=±l sem. — α~ indicates fibronectin, and --•-- indicates fibrinogen.
[0025] FIG. 8 A. Photomicrographs of co-cultures of liver hepatocytes and microenviromental cells on PGA felt 30 days after grafting into Long-Evans rats. H-E staining. Low power view of a subcutaneous graft showing a focus of hepatic tissue (H) contiguous to connective tissue (C) in the process of reorganization. A tract of residual, partially hydrolyzed PGA polymers (p) is present. Arrows identify putative biliary structures associated with the regenerating hepatic tissue. 100 X.
[0026] FIG. 8B. Photomicrographs of co-cultures of liver hepatocytes and microenviromental cells on PGA felt 30 days after grafting. The interface between grafted liver co-cultures (L) and connective tissue (C) elements of the omentum. Sinusoids (s) are evident.
[0027] FIG. 8C. Photomicrographs of co-cultures of liver hepatocytes and microenviromental cells on PGA felt 30 days after grafting. Graft site in the mesentery showing hepatocytes with sinusoids (lower right), connective tissue in the process of repair
(C), and hepatocytes interspersed between connective tissue elements in the absence of developing sinusoidal structures (top left). 500 X.
5. DEFINITIONS
[0028] The term 'about' or 'approximately' means within 20%, preferably within 10%, and more preferably within 5% (or 1% or less) of a given value or range.
- 5 -
LAI-2875394v7 [0029] As used herein, 'administer' or 'administration' refers to the act of injecting or otherwise physically delivering a substance as it exists outside the body (e.g., a composition provided herein) into a patient, such as by mucosal, intradermal, intravenous, intramuscular delivery and/or any other method of physical delivery described herein or known in the art.
When a disease, or a symptom thereof, is being treated, administration of the substance typically occurs after the onset of the disease or symptoms thereof. When a disease, or symptoms thereof, are being prevented, administration of the substance typically occurs before the onset of the disease or symptoms thereof.
[0030] As used herein, the term 'composition' is intended to encompass a product containing the specified ingredients in, optionally, the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in, optionally, the specified amounts.
[0031] 'Conditioned medium,' 'conditional cell medium,' or 'conditioned cell and tissue culture medium' refers to a formulation containing extracellular protein(s) and cellular metabolites, which has previously supported the growth of any desired cell type, said cells having been cultured in three dimensions.
[0032] A biologically active molecule is 'derived' or 'culture-derived' from a conditional medium refers to a molecule of conditioned cell culture medium that is not present in the starting cell culture medium that is used to culture and feed the cells, but is produced by the cultured cells and enters the medium, or a molecule that is initially present in the pre-conditioned media, but whose concentration is increased during the culture process.
[0033] The term 'effective amount' as used herein refers to the amount of a therapy
(e.g., a composition provided herein) which is sufficient to reduce and/or ameliorate the severity and/or duration of a given disease and/or a symptom related thereto. This term also encompasses an amount necessary for the reduction or amelioration of the advancement or progression of a given disease, reduction or amelioration of the recurrence, development or onset of a given disease, and/or to improve or enhance the prophylactic or therapeutic effect(s) of another therapy.
[0034] The term 'excipients' as used herein refers to inert substances which are commonly used as a diluent, vehicle, preservatives, binders, or stabilizing agent for drugs
- 6 -
LAI-2875394v7 and includes, but not limited to, proteins (e.g., serum albumin, etc.), amino acids (e.g., aspartic acid, glutamic acid, lysine, arginine, glycine, histidine, etc.), fatty acids and phospholipids (e.g., alkyl sulfonates, caprylate, etc.), surfactants (e.g., SDS, polysorbate, nonionic surfactant, etc.), saccharides (e.g., sucrose, maltose, trehalose, etc.) and polyols (e.g., mannitol, sorbitol, etc.). See also Remington's Pharmaceutical Sciences (18th Ed., 1995), which is hereby incorporated by reference in its entirety.
[0035] The term 'extracellular matrix' or 'ECM' encompasses essentially all secreted molecules that are immobilized outside of the cell. In vivo, the ECM provides order in the extracellular space and serves functions associated with establishing, separating, and maintaining differentiated tissues and organs. The ECM is a complex structure that is found, for example, in connective tissues and basement membranes, also referred to as the basal lamina. Connective tissue typically contains isolated cells surrounded by ECM that is naturally secreted by the cells. Exemplary ECM include but are not limited to, collagen type I, collagen type II, collagen type III, collagen type IV, collagen type V, collagen type VI, collagen type VII, collagen type VIII, collagen type IX, collagen type X, collagen type XI, collagen type XII, collagen type XIII, collagen type XIV, collagen type XV, collagen type XVI, collagen type XVII, collagen type XVIII, fibronectin, laminin, particularly laminin-1, laminin-2, laminin-4, and laminin-5, lumican, tenascin, versican, perlecan, thrombospondin, particularly thrombospondin-2 and thrombospondin-4, or laminin, particularly laminin-1, -2, -4, and -5, agrin, nidogen, bamacan, decorin, biglycan, fibromodulin, elastin, fibrillin, hyaluronan, vitronectin, chondroitin sulphate, dermatan sulphate, heparan sulphate, and keratan sulphate.
[0036] As used herein, the terms 'manage,' 'managing,' and 'management' refer to the beneficial effects that a subject derives from a therapy, which does not result in a cure of the disease. In certain embodiments, a subject is administered one or more therapies (e.g., a composition of the invention) to 'manage' a disease or disorder, one or more symptoms thereof, so as to prevent the progression or worsening of the disease. [0037] 'Microenviromental cells' refers to fibroblasts with or without other cells and/or elements found in loose connective tissue, including, but not limited to, endothelial cells, pericytes, macrophages, monocots, plasma cells , mast cells, adipocytes, mesenchymal stem
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LAl-2875394v7 cells, liver reserve cells. Specifically, microenviromental cells of liver may include fibroblasts, Kupffer cells and vascular and bile duct endothelial cells.
[0038] The term 'pharmaceutically acceptable' as used herein means being approved by a regulatory agency of the Federal or a state government, or listed in the U.S. Pharmacopeia,
European Pharmacopeia or other generally recognized Pharmacopeia for use in animals, and more particularly in humans.
[0039] As used herein, the terms 'prevent,' 'preventing,' and 'prevention' refer to the total or partial inhibition of the development, recurrence, onset or spread of a disease and/or symptom related thereto, resulting from the administration of a therapy or combination of therapies provided herein {e.g., a combination of compositions provided herein).
[0040] As used herein, the terms 'subject' and 'patient' are used interchangeably. As used herein, a subject is preferably a mammal, such as a non-primate (e.g., cows, pigs, horses, cats, dogs, rats, etc.) or a primate (e.g., monkey and human), most preferably a human.
[0041] As used herein, the term 'therapy' refers to any protocol, method and/or agent that can be used in the prevention, management, treatment and/or amelioration of a disease.
In certain embodiments, the terms 'therapies' and 'therapy' refer to a biological therapy, supportive therapy, and/or other therapies useful in the prevention, management, treatment and/or amelioration of a disease known to one of skill in the art, such as medical personnel.
[0042] 'Three-dimensional framework' refers to a three-dimensional scaffold composed of any material and/or shape that (a) allows cells to attach to it (or can be modified to allow cells to attach to it); and (b) allows cells to grow in more than one layer. This support is inoculated with microenviromental cells to form the living three-dimensional microenviromental tissue. The structure of the framework can include a mesh, a sponge or can be formed from a hydrogel.
[0043] "Three-dimensional microenviromental tissue' or 'living microenviromental matrix' refers to a three-dimensional framework which has been inoculated with microenviromental cells that are grown on the support. The extracellular matrix proteins elaborated by the microenviromental cells are deposited onto the framework, thus forming a living microenviromental tissue. The living microenviromental tissue can support the growth of hepatocytes inoculated to form the three-dimensional cell culture.
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LAI-2875394v7 [0044] As used herein, the terms 'treat,' 'treatment' and 'treating' refer to the reduction or amelioration of the progression, severity, and/or duration of a disease resulting from the administration of one or more therapies (including, but not limited to, the administration of one or more compositions provided herein).
6. DETAILED DESCRIPTION OF THE INVENTION
(0045] The present invention relates to a method for the production of a composition comprising a biologically active molecule, such as a bile acid, derived from a conditioned culture medium by using a three-dimensional, multi-layer cell culture system. Also provided herein is a composition produced by this method, as well as methods of using the composition for use in the treatment of diseases or disorders, and/or the alleviation of a symptom of a disease or disorder thereof.
[0046] In previously known tissue culture systems, the cells were grown in a monolayer. Cells cultured on a three-dimensional microenviromental cell framework, in accordance with the present invention, grow in multiple layers, forming a tissue. This three- dimensional approaches physiologic conditions found in vivo to a greater degree than previously described monolayer tissue culture systems. The three-dimensional cell culture system is applicable to the proliferation of liver cells, formation of liver tissues and synthesis of bile acids by liver cells.
[0047] In accordance with the methods provided herein, hepatocytes are inoculated and cultured on a pre-established three-dimensional microenviromental tissue. The microenviromental tissue comprises microenviromental cells grown on a three-dimensional matrix or framework. The microenviromental cells comprise fibroblasts with or without additional cells and/or elements described more fully herein. The fibroblasts and other cells and/or elements that comprise the microviromental tissue can be fetal or adult in origin, and can be derived from convenient sources, such as skin, liver, pancreas, etc. Such tissues and/or organs can be obtained by appropriate biopsy or upon autopsy. In fact, cadaver organs can be used to provide a generous supply of microenviromental cells and elements. [0048] Neonatal fibroblasts can support the growth of many different cells and tissues in the three-dimensional culture system, and, therefore, can be inoculated onto the matrix to form a 'generic' microenviromental tissue for culturing any of a variety of cells and tissues,
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LAI-2875394v7 including hepatocytes. However, in certain instances, it may be preferable to use a 'specific' rather than 'generic' microenviromental tissue, in which case microenviromental cells and elements can be obtained from a liver tissue. Fibroblasts and other microenviromental cells and/or elements can be derived from the same type of tissue to be cultured in the three-dimensional system. This might be advantageous, for example, when culturing liver tissues in which specialized microenviromental cells can play particular structural/functional roles; e.g., Kupffer cells of liver.
[0049] Once inoculated onto the three-dimensional framework, the microenviromental cells will proliferate on the framework and support the growth of hepatocytes inoculated into the three-dimensional culture system of the invention. In fact, when inoculated with hepatocytes, the three-dimensional microenviromental tissue will sustain active proliferation of the culture for long periods of time. Growth and regulatory factors can be added to the culture, but are not necessary since they are elaborated by the microenviromental tissue. In certain embodiments, one or more agents that increase the synthesis or formation of bile acids are added to the culture.
[0050J Because it is important to recreate, in culture, the cellular microenvironment found in vivo for a particular tissue, the extent to which the microviromental cells are grown prior to inoculation of hepatocytes can vary depending on the type of tissue to be grown in three-dimensional tissue culture. Importantly, because openings in the mesh permit the exit of microenviromental cells in culture, confluent microenviromental cultures do not exhibit contact inhibition, and the microenviromental cells continue to grow, divide, and remain functionally active.
[0051] The invention is based, in part, upon the discovery that growth of the microenviromental cells in three dimensions will sustain active proliferation of both the microenviromental and tissue-specific cells in culture for much longer time periods than will monolayer systems. Moreover, the three-dimensional system supports the maturation, differentiation, and segregation of liver cells in culture in vitro to form components of adult liver tissues analogous to counterparts found in vivo. The three-dimensional system is useful for the production of biologically active molecules produced by liver cells, such as bile acids.
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LAI-2875394v7 [0052] Without limiting to any theory in particular, Applicants believe a number of factors inherent in the three-dimensional culture system can contribute to its success:
(a) The three-dimensional framework provides a greater surface area for protein deposition, and consequently, for the adherence of microenviromental cells.
(b) Because of the three-dimensionality of the framework, microenviromental cells continue to actively grow, in contrast to cells in monolayer cultures, which grow to confluence, exhibit contact inhibition, and cease to grow and divide. The elaboration of growth and regulatory factors by replicating microenviromental cells can be partially responsible for stimulating proliferation and regulating differentiation of cells in culture.
(c) The three-dimensional framework allows for a spatial distribution of cellular elements which is more analogous to that found in the counterpart tissue in vivo.
(d) The increase in potential volume for cell growth in the three-dimensional system can allow the establishment of localized microenvironments conducive to cellular maturation.
(e) The three-dimensional framework maximizes cell-cell interactions by allowing greater potential for movement of migratory cells, and for the establishment of communications between hepatocytes and the various types of microenviromental cells, such as macrophages, in the adherent layer.
(f) It has been recognized that maintenance of a differentiated cellular phenotype requires not only growth/differentiation factors but also the appropriate cellular interactions. The present invention effectively recreates the tissue microenvironment.
[0053] The three-dimensional microenviromental support, the culture system itself, and its maintenance, as well as its use for the production of a biologically active molecule are described in greater detail in the subsections below.
6.1 METHODS FOR PRODUCING COMPOSITIONS COMPRISING A BIOACTIVE MOLECULE USING A THREE-DIMENSIONAL CELL AND CULTURE SYSTEM
[0054] The present invention provides a method for producing a composition comprising a biologically active molecule from a conditioned culture medium using a three- dimensional cell and tissue culture system. In certain embodiments, the biological active molecule is culture-derived from a conditioned culture medium using a three-dimensional liver cells culture. In some embodiments, the biologically active molecule is a bile acid,
- 1 1 -
LΛI-2875394v7 bile acid derivative, bile acid salt, bile acid conjugate, or any combination thereof. It is noted that reference to a 'bile acid' herein is meant to include the bile acid itself, as well as any bile acid derivative, salt, or conjugate thereof, either individually or any combination thereof In certain embodiments, the biologically active molecule is ursodeoxycholic acid ('UDCA') or derivative, salt, conjugate or combination thereof.
[0055 J In some embodiments, the present invention provides a method for producing a bile acid, or its derivative, salt or conjugate thereof, comprising isolating the bile acid, or its derivative, salt or conjugate thereof from a conditioned culture medium, wherein the culture medium is conditioned by hepatocytes in three-dimensional culture. [0056] In some embodiments, the present invention provides a method for producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, comprising combining a conditioned culture medium with an appropriate carrier, wherein the culture medium is conditioned by hepatocytes in three-dimensional culture. Appropriate carriers can be neutraceutically acceptable carriers or pharmaceutically acceptable carriers which are described below.
[0057] In some embodiments, the present invention provides a method for producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, comprising isolating the bile acid or its derivative salt or conjugate thereof from a conditioned culture medium and the cell medium is conditioned by hepatocytes cultured on a living microenviromental cell tissue prepared in vitro, comprising microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells attached to and substantially enveloping a framework composed of a biocompatible, non-living material formed into a three-dimensional structure having interstitial spaces bridged by the microenviromental cells, so that the hepatocytes proliferate and secrete a bile acid, or its derivative, salt or conjugate thereof into the conditioned medium.
[0058] In some embodiments, the present invention provides a method for producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, comprising: (a) inoculating liver hepatocytes onto a living microenviromental cell tissue prepared in vitro, comprising microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells attached to and substantially enveloping a framework composed of a biocompatible, non-living material formed into a three-dimensional structure
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LΛI-2875394v7 having interstitial spaces bridged by the microenviromental cells; (b) incubating the inoculated living microenviromental cell tissue in a medium so that the inoculated cells proliferate in culture; (c) collecting the medium; and (d) isolating the bile acid, or derivative, salt or conjugate thereof from the collected medium of step (c).
6.1.1 Pre-Conditioned Culture Media
[0059] The 'pre-conditioned' cell culture medium can be any cell culture medium which adequately addresses the nutritional needs of the cells being cultured. Cell culture media are well known in the literature and many are commercially available. Examples of cell media include, but are not limited to William's Medium E (WME), Dulbecco's Modified Eagle's Medium (DMEM), Ham's F12, RPMI 1640, Iscove's, McCoy's and other media formulations readily apparent to those skilled in the art, including those found in Methods For Preparation of Media, Supplements and Substrate For Serum-Free Animal Cell Culture Alan R. Liss, New York (1984) and Cell &Tissue Culture: Laboratory Procedures, John Wiley & Sons Ltd., Chichester, England 1996, both of which are incorporated by reference herein in their entirety. The medium can be supplemented, with any components necessary to support the desired cell or tissue culture. Additionally serum, such as bovine serum, which is a complex solution of albumins, globulins, growth promoters and growth inhibitors can be added if desired. The serum generally should be pathogen free and carefully screened for mycoplasma bacterial, fungal, and viral contamination. Also, the serum should generally be obtained from the United States and not obtained from countries where indigenous livestock carry transmittable agents. Hormone addition into the medium may or may not be desired.
[0060] Other ingredients, such as vitamins, growth and attachment factors, proteins etc. , can be selected by those of skill in the art in accordance with particular need. [0061] The pre-conditioned medium can also contain one or more agents that facilitate the synthesis, formation or secretion of biologically active molecules of interests.
6.1.2 Cells
[0062] The present invention can use any cell type appropriate to achieve the desired conditioned medium. In certain embodiments, the medium are conditioned by hepatocytes to generate a conditioned medium containing a bile acid or its derivative, salt or conjugate or combinations thereof. Hepatocytes from any species can be used in generating
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LA!-2875394v7 conditioned culture medium. In some embodiments, hepatocytes are human, primate, bear, cow, dog, rodent, pig or turkey hepatocytes. In preferred embodiments, hepatocytes are bear hepatocytes. In certain embodiments, bear hepatocytes are from American black bear (Ursus Americanus), Asiatic black bear {Selenarctos thibetanus), polar bear (Ursus maritimus), brown bear (Ursus arctos), sun bear (Helarctosjnalayanus), giant panda (Alluropoda melanoleucά), sloth bear (Melursus ursinus) or spectacled bear (Tremarctus ornatus).
[0063] Genetically engineered cells can be used to culture the media. Such cells can be modified, for example, to express a desired protein or proteins so that the concentration of the expressed protein or proteins in the medium is optimized for the particular desired application. In accordance with the present invention, the cells and tissue cultures used to condition the medium can be engineered to express a target gene product which can impart a wide variety of functions, including, but not limited to, improved properties in expressing proteins resembling physiological reactions, increased expression of a particular protein useful for a specific application, such as wound healing or inhibiting certain proteins, such as proteases, lactic acid, etc.
6.1.3 Microenviromental Cells
[0064] The microenviromental cells used in the three-dimensional cultures comprise fibroblasts, mesenchymal stem cells, liver reserve cells, neural stem cells, pancreatic stem cells, and/or embryonic stem cells with or without additional cells and/or elements described more fully herein.
[0065] Fibroblasts will support the growth of many different cells and tissues in the three-dimensional culture system, and, therefore, can be inoculated onto the matrix to form a 'generic' microenviromental support matrix for culturing any of a variety of cells and tissues. However, in certain instances, it can be preferable to use a 'specific' rather than 'generic' microenviromental support matrix, in which case microenviromental cells and elements can be obtained from a particular tissue, organ, or individual. Moreover, fibroblasts and other microenviromental cells and/or elements can be derived from the same type of tissue to be cultured in the three-dimensional system. This might be advantageous when culturing tissues in which specialized microenviromental cells can play particular
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LAl-2875394v7 structural/functional roles; e.g., smooth muscle cells of arteries, glial cells of neurological tissue, Kupffer cells of liver, etc.
[0066] Once inoculated onto the three-dimensional support, the microenviromental cells will proliferate on the framework and deposit the connective tissue proteins naturally secreted by the microenviromental cells, such as growth factors, regulatory factors and/or extracellular matrix proteins. The microenviromental cells and their naturally secreted connective tissue proteins substantially envelop the framework thus forming the living microenviromental tissue which will support the growth of tissue-specific cells inoculated into the three-dimensional culture system of the invention. In fact, when inoculated with the tissue-specific cells, the three-dimensional microenviromental tissue will sustain active proliferation of the culture for long periods of time. Importantly, because openings in the mesh permit the exit of microenviromental cells in culture, confluent microenviromental cultures do not exhibit contact inhibition, and the microenviromental cells continue to grow, divide, and remain functionally active.
[0067] Growth and regulatory factors are elaborated by the microenviromental tissue into the media. Growth factors (for example, but not limited to, α FGF, β FGF, insulin growth factor or TGF-betas), or natural or modified blood products or other bioactive biological molecules (for example, but not limited to, hyaluronic acid or hormones), enhance the colonization of the three-dimensional framework or scaffolding and condition the culture media.
[0068] The extent to which the microenviromental cells are grown prior to use of the cultures in vivo can vary depending on the type of tissue to be grown in three-dimensional tissue culture. The living microenviromental tissues which condition the medium can be used as corrective structures by implanting them in vivo. Alternatively, the living microenviromental tissues can be inoculated with another cell type and implanted in vivo. The microenviromental cells can be genetically engineered to adjust the level of protein products secreted into the culture medium to improve the concentration of recovered product obtained from the conditioned medium.
[0069] Growth of the microenviromental cells in three-dimensions will sustain active proliferation of both the microenviromental and tissue-specific cells in culture for much longer time periods than will monolayer systems. Moreover, the three-dimensional system
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LΛI-2875394v7 supports the maturation, differentiation, and segregation of cells in culture in vitro to form components of adult tissues analogous to counterparts found in vivo and secure proteins into the conditional medium more closely resembling physiological ratios.
6.1.4 ESTABLISHMENT OF THREE-DIMENSIONAL MICROENVIROMENTAL MATRIX
[0070] The three-dimensional support framework can be of any material and/or shape that: (a) allows cells to attach to it (or can be modified to allow cells to attach to it); and (b) allows cells to grow in more than one layer. A number of different materials can be used to form the framework, including but not limited to: nylon (polyamides), dacron (polyesters), polystyrene, polypropylene, polyacrylates, polyvinyl compounds (e.g., polyvinylchloride), polycarbonate (PVC), polytetrafluorethylene (PTFE; teflon), thermanox (TPX), nitrocellulose, cotton, polyglycolic acid (PGA), cat gut sutures, cellulose, gelatin, dextran, etc. Any of these materials can be woven into a mesh, for example, to form the three- dimensional framework. Certain materials, such as nylon, polystyrene, etc. , can be used, but are less preferred as they tend to be poor substrates for cellular attachment. When these materials are used as the three-dimensional support framework, it is advisable to pre-treat the matrix prior to inoculation of microenviromental cells in order to enhance the attachment of microenviromental cells to the framework. For example, prior to inoculation with microenviromental cells, nylon screens could be treated with 0.1 M acetic acid, and incubated in polylysine, FBS, and/or collagen to coat the nylon. Polystyrene could be similarly treated using sulfuric acid.
[0071] In some embodiments, biodegradable materials, such as PGA, catgut suture material, collagen, polylactic acid, or hyaluronic acid can be used in the three-dimensional support framework. For example, these materials can be woven into a three-dimensional framework, such as a collagen sponge. In other embodiments, non-degradable materials, such as nylon, dacron, polystyrene, polyacrylates, polyvinyls, teflons, cotton, etc. can be used. A convenient nylon mesh which could be used in accordance with the invention is NITEX, a nylon filtration mesh having an average pore size of 140 μm and an average nylon fiber diameter of 90 μm (#3-210/36, Tetko, Inc., N. Y.).
[0072] Microenviromental cells comprising fibroblasts, with or without other cells and elements described below, can be inoculated onto the framework. These microenviromental
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LAI-2875394v7 cells can be derived from organs, such as skin, liver, pancreas, etc., which can be obtained by biopsy (where appropriate) or upon autopsy. In fact fibroblasts can be obtained in quantity rather conveniently from any appropriate cadaver organ. As previously explained, fetal fibroblasts can be used to form a 'generic' three-dimensional microenviromental tissue that will support the growth of a variety of different cells and/or tissues. However, a 'specific' microenviromental tissue can be prepared by inoculating the three-dimensional framework with microenviromental cells derived from the liver. Liver microenviromental cells include, but are not limited to, Kupffer cells, endothelial cells, fat storing cells and fibroblasts.
[0073] Microenviromental cells can be readily isolated by disaggregating an appropriate organ or tissue. This can be readily accomplished using techniques known to those skilled in the art. For example, the tissue or organ can be disaggregated mechanically and/or treated with digestive enzymes and/or chelating agents that weaken the connections between neighboring cells making it possible to disperse the tissue into a suspension of individual cells without appreciable cell breakage. Enzymatic dissociation can be accomplished by mincing the tissue and treating the minced tissue with any of a number of digestive enzymes either alone or in combination. These include, but are not limited to, trypsin, chymotrypsin, collagenase, elastase, and/or hyaluronidase, DNase, pronase, dispase, etc. Mechanical disruption can also be accomplished by a number of methods including, but not limited to, the use of grinders, blenders, sieves, homogenizers, pressure cells, or insonators. For a review of tissue disaggregation techniques, see, e.g., Freshney, Culture of Animal Cells. A Manual of Basic Technique (2nd Ed. 1987), A. R. Liss, Inc., New York, Ch. 9, pp. 107-126. [0074] Once the tissue has been reduced to a suspension of individual cells, the suspension can be fractionated into subpopulations from which the fibroblasts and/or other microenviromental cells and/or elements can be obtained. This can also be accomplished using standard techniques for cell separation including, but not limited to, cloning and selection of specific cell types, selective destruction of unwanted cells (negative selection), separation based upon differential cell agglutinability in the mixed population, freeze-thaw procedures, differential adherence properties of the cells in the mixed population, filtration, conventional and zonal centrifugation, centrifugal elutriation (counter-streaming centrifugation), unit gravity separation, countercurrent distribution, electrophoresis and
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I.AI-2875394v7 fluorescence-activated cell sorting. For a review of clonal selection and cell separation techniques, see, e.g., Freshney, Culture of Animal Cells. A Manual of Basic Technique (2nd Ed. 1987), A. R. Liss, Inc., New York, Ch. 1 1 and 12, pp. 137-168. [0075] The isolation of microenviromental cells can, for example, be carried out as follows: fresh tissue samples are thoroughly washed and minced in Hanks Balanced Salt Solution (HBSS) in order to remove serum. The minced tissue is incubated from 1-12 hours in a freshly prepared solution of a dissociating enzyme, such as trypsin. After such incubation, the dissociated cells are suspended, pelleted by centrifugation and plated onto culture dishes. All microenviromental cells will attach before other cells. Thus, appropriate microenviromental cells can be selectively isolated and grown. The isolated microenviromental cells can then be grown to confluency, lifted from the confluent culture and inoculated onto the three-dimensional framework (see, e.g., Naughton et ah, 1987, J. Med. 18(3&4):219-250). Inoculation of the three-dimensional framework with a high concentration of microenviromental cells, e.g., approximately 106 to 5X107 cells/ml, will result in the establishment of the three-dimensional microenviromental tissue in shorter periods of time.
[0076] In addition to fibroblasts, other cells can be added to form the three-dimensional microenviromental tissue required to support long term growth in culture. For example, other cells found in loose connective tissue can be inoculated onto the three-dimensional framework along with fibroblasts. Such cells include, but are not limited to, endothelial cells, pericytes, macrophages, monocytes, adipocytes, etc. These microenviromental cells can readily be derived from appropriate organs, such as skin, liver, etc. , using methods known in the art, such as those discussed above. In a specific embodiment of the invention, liver microenviromental cells, which include Kupffer cells, endothelial cells, adipocytes and fibroblasts, are inoculated onto the framework collectively.
[0077] The growth of cells in the presence of the three-dimensional microenviromental support framework can be further enhanced by adding to the framework or coating it with proteins {e.g., collagens, elastin fibers, reticular fibers) glycoproteins, glycosaminoglycans (e.g. , heparan sulfate, chondroitin-4-sulfate, chondroitin-6-sulfate, dermatan sulfate, keratan sulfate), a cellular matrix, and/or other materials.
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LAI-2875394v7 [0078) After inoculation of the microenviromental cells, the three-dimensional framework should be incubated in an appropriate nutrient medium. Many commercially available media, such as WME, DMEM, RPMI 1640, Fisher's, Iscove's, McCoy's, and the like can be suitable for use. It is important that the three-dimensional microenviromental tissue be suspended in the medium during the incubation period in order to maximize proliferative activity. In addition, the culture should be 'fed' periodically to remove the spent media, depopulate released cells, and add fresh media.
[0079] During the incubation period, the microenviromental cells will grow linearly along and envelop the filaments of the three-dimensional framework before beginning to grow into the openings of the framework. It is important to grow the cells to an appropriate degree which reflects the proportion of microenviromental cells present in the in vivo tissue prior to inoculation of the microenviromental tissue with hepatocytes. [0080] The openings of the framework should be of an appropriate size to allow the microenviromental cells to stretch across the openings. Maintaining actively growing microenviromental cells which stretch across the framework enhances the production of growth factors that are elaborated by the microenviromental cells, and hence will support long term cultures. For example, if the openings are too small, the microenviromental cells can rapidly achieve confluence but be unable to easily exit from the mesh, and trapped cells can exhibit contact inhibition and cease production of the appropriate factors necessary to support proliferation and maintain long term cultures. If the openings are too large, the microenviromental cells can be unable to stretch across the opening, and this will also decrease microenviromental cell production of the appropriate factors necessary to support proliferation and maintain long term cultures. When using a mesh type of framework, as exemplified herein, it has been found that openings ranging from about 140 μm to about 220 μm can work satisfactorily. However, depending upon the three-dimensional structure and intricacy of the framework, other sizes can work equally well. In fact, any shape or structure that allows the microenviromental cells to stretch and continue to replicate and grow for lengthy time periods will work in accordance with the invention. [0081] Different proportions of the various types of collagen deposited on the matrix can affect the growth of the later inoculated hepatocytes. The proportions of ECM proteins deposited can be manipulated or enhanced by selecting fibroblasts which elaborate
- 19 - l.AI-2875394v7 the appropriate collagen type. This can be accomplished using monoclonal antibodies of an appropriate isotype or subclass that is capable of activating complement, and which define particular collagen types. These antibodies and complement can be used to negatively select the fibroblasts which express the desired collagen type. Alternatively, the microenviromental cells used to inoculate the framework can be a mixture of cells which synthesize the appropriate extracellular matrix or collagen types desired. The distribution and origins of the five types of collagen is shown in Table I. The types of cells used to inoculate onto the microenviromental framework can be selected based on the extracellular matrix as shown in the following table. The extracellular matrix of liver is described in detail, for example, in Martinez-Hernandez et al, 1993, Virchows Archiv A Pathol. Anat. 423: 1-11 ; Zern et al, 1993. Extracellular Matrix. Chemistry. Biology and Pathobiology with Emphasis on Liver (Mercel Dekker Inc.).
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LAI-2875394v7 [0082] TABLE I - DISTRIBUTIONS AND ORIGINS OF EXTRACELLULAR MATRIX IN LIVER
Figure imgf000023_0001
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LAI-2875394v7 (0083) Thus, since the three-dimensional culture system described herein is suitable for the growth of diverse cell types and tissues, and depending upon the tissue to be cultured and the collagen types desired, the appropriate microenviromental cell(s) can be selected to inoculate the three-dimensional framework. However, for the practice of the present invention, microenviromental cells isolated from the liver are preferred for use to support the growth of hepatocytes.
[0084] During incubation of the three-dimensional microenviromental support, proliferating cells can be released from the framework. These released cells can stick to the walls of the culture vessel where they can continue to proliferate and form a confluent monolayer. This should be prevented or minimized, for example, by removal of the released cells during feeding, or by transferring the three-dimensional microenviromental tissue to a new culture vessel. The presence of a confluent monolayer in the vessel can 'shut down' the growth of cells in the three-dimensional culture. Removal of the confluent monolayer or transfer of the microenviromental tissue to fresh media in a new vessel will restore proliferative activity of the three-dimensional culture system. Such removal or transfers should be done in any culture vessel which has a microenviromental monolayer exceeding 25% confluency. Alternatively, the culture system could be agitated to prevent the released cells from sticking, or instead of periodically feeding the cultures, the culture system could be set up so that fresh media continuously flows through the system. The flow rate could be adjusted to both maximize proliferation within the three-dimensional culture and wash out and remove cells released from the matrix so that they will not stick to the walls of the vessel and grow to confluence. In any case, the released microenviromental cells can be collected and crypreserved for future use.
6.1.5 THREE-DIMENSIONAL LIVER TISSUE CULTURE SYSTEM
[0085] Hepatocytes from any species can be used in the described three-dimensional liver tissue culture system. In some embodiments, hepatocytes are human, primate, bear, cow, dog, rodent, pig or turkey hepatocytes. In preferred embodiments, hepatocytes are bear hepatocytes. In certain embodiments, bear hepatocytes are from American black bear (Ursus Americanus), Asiatic black bear (Selenarctos thibetanus), polar bear (Ursus maήtimus), brown bear {Ursus arctos), sun bear {Helarctosjnalayanus), giant panda
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LAI-2875394v7 (Alluropoda melanoleuca), sloth bear (Melursus ursinus) or spectacled bear (Tremarctus ornatns).
[0086] Hepatocytes can be isolated by conventional methods (see, e.g. , Berry and Friend, 1969, J. Cell Biol. 43:506- 520) which can be adapted for bear liver biopsy or autopsy material. Briefly, a cannula is introduced into the portal vein or a portal branch, and the liver is perfused with calcium-free or magnesium-free buffer until the tissue appears pale. The organ is then perfused with a proteolytic enzyme, such as a collagenase solution at an adequate flow rate to digest the connective tissue framework. The liver is then washed in buffer and the cells are dispersed. The cell suspension can be filtered through a 70 μm nylon mesh to remove debris. Hepatocytes can be selected from the cell suspension by various established methods including differential centrifugation against various gradients [0087] For perfusion of individual lobes of excised bear liver, HEPES buffer can be used. Perfusion of collagenase in HEPES buffer can be accomplished at the rate of about 10, 20, 30, 40, 50, 75, 100, 150 or 200 ml/minute. A single cell suspension is obtained after perfusion with a single type of collagenase, mixed with collagneases, collagenase/dispase, collagenase/pronase or other enzyme mixture for 20 minutes at 370C. (See, e.g., Guguen- Guillouzo and Guillouzo, eds, 1986, 'Isolated and Culture Hepatocytes' Paris, INSERM, and London, John Libbey Eurotext, pp. 1-12; 1982, Cell Biol. Int. Rep. 6:625-628). [0088] The isolated hepatocytes can then be used to inoculate the three-dimensional microenviromental tissue. Hepatocytes function in vitro can be maintained over longer time periods if they are cultured with various ECM substances or co-cultured with other microenviromental cell types, although cellular proliferation is low or absent in these systems after the first several days of culture (Michalopoulos et al., 1975, Exp. Cell Res. 94:70-78; Dunn e/ α/., 1989, FASEB J. 3:174-177; Reid e/ α/., 1980, Ann. N. Y. Acad. Sci. 349:70-76; Bissell et al., 1987, J. Clin. Invest. 79:801-812; Deschenes et al, 1980, In vitro 16:722-730; Guguen-Guilluozo et al, 1983, Exp. Cell Res. 143:47-54; Begue et al., 1983, Biochem. Pharmacol. 32: 1643-1646; Kuri-Harcuch et al , 1989, Differentiation 41 : 148- 157).
[0089] three-dimensional frameworks, such as the nylon screens, not only provide an increased surface area for cell growth but apparently allow hepatocytes and microenviromental cells to form a microenvironment conducive to expression of liver-
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LAI-2875394v7 specific metabolic activity as well as hepatocytes proliferation. Hepatocytes that are inoculated onto a three-dimensional framework containing the various types of liver microenviromental cells self assemble into liver-specific structures and form various cell- cell interactions including hepatocytes-Kupffer cell, hepatocytes-vascular endothelial cell, PC-biliary endothelial cell, PC-stellate cell, PC-adipoctyes as well as the various combinations of microenviromental cells. Contiguous hepatocytes form bile canaliculi into which they synthesize bile acids, albumin, fibrinogen, transferrin and other proteins are released basolaternall into the medium. Hepatocytes display cP450 metabolism, including induction and inhibition for > two month in culture. Growth of hepatocytes is evident in association with these microenviromental cell and can proceed until all available space for expansion within the framework is exhausted. Albumin secretion by hepatocytes increases by >700% over 'time zero' levels by 24 days of co-culture (0.66±0.32 vs. 5.5±0.70 μg/ml; P±O.01) and although the levels drop thereafter, they remain about 400% greater than input levels at 48 days of co-culture (0.66±0.32 vs. 3.28±0.59 μg/ml; P±O.025). This result compares favorably to the monolayer-based co-culture system of Guguen-Guillouzo et al, which reported peak albumin levels at about +300% of input cells after 10 days of co- culture but observed a steady decline thereafter until 42 days when the levels of this protein were essentially equal to the quantities secreted by input cells (Guguen-Guilluozo et al, 1983, Exp. Cell Res. 143:47-54). In the three-dimensional nylon screen co-cultures, albumin synthesis, and possibly the production of other proteins, are related to proliferative activity and/or the cell density of the framework. As the nylon screens become filled with hepatocytes, 3H-thymidine incorporation and cell division drop dramatically; albumin and fibronectin synthesis also decrease as the cultures reach their maximum capacity of total cells. This decline of albumin synthesis is the result of decreased metabolic activities of these cells, and it is not a loss of liver specific function. The three-dimensional culture system of the present invention maximizes cell-cell contact which enhances hepatocyte protein synthesis in vitro.
[0090] Although hepatocyte proliferation can be difficult to quantify in co-cultures because of the presence of other cell types, hepatocyte growth is evident in histological sections through the three-dimensional cultures. Hepatocytes are the largest cells of the co- culture and unlike stroma, which are irregularly-shaped and branched cells, are round.
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LAI-2875394v7 US2009/004038
These large, round cells stain positively for the liver hepatocytes-associated proteins albumin, fibrinogen, transferrin, and cytokeratin 19. This finding is confirmed by differential counts of cells derived from the co-cultures in which hepatocytes are distinguished from non-hepatocytes by virtue of their size, nuclear: cytoplasmic volume, nuclear characteristics, and lack of ability to phagocytose colloidal carbon and react with antibodies directed against endothelial cell epitopes. These findings, coupled with radiothymidine incorporation studies, indicate that hepatocytes proliferation occurs over a ±4 week period in the present three-dimensional model. Such a phenomenon has not been demonstrated in any other liver culture systems for longer than 1 week. A limiting aspect of this cell expansion appears to be space. Hepatocytes grow only in association with stroma and their rates of growth decline as the framework become filled with cells. [0091] Although it appears that most hepatocytes have the capacity to synthesize albumin in vivo, the quantity and rate of expression of this protein varies with location within the acinus (Bernuau et α/., 1981, Biol. Cell 40:17-14 22; Guillouzo et al, 1982, Biol. Cell 43: 163-171). In contrast to normal conditions where only 15-20% of the total liver hepatocytes strongly express albumin (Schreiber et al, 1970, J. Cell Biol. 47:285-290; Araki et al, 1992, Acta Anat. 143:169-177), virtually all hepatocytes express this protein following hepatotoxic injury (Araki et al, 1992, Acta Anat. 143: 169-177) or in response to perturbations in plasma proteins associated with nephrotic syndrome (Maurice et al, 1979, Lab. Invest. 40:39-45). It is possible that initially, most hepatocytes inoculated onto the nylon screen/microenviromental tissue synthesize albumin and that this model, in some respects, resembles regenerating or injured liver. As hepatocytes fill the framework, their proliferation rate slows, and albumin as well as fibronectin synthesis decline in the majority of the cells, presumably because of ECM or other microenviromental factors. In this respect, ECM substances influence cell division and gene expression in hepatic cells (Michalopoulos et al, 1979, In vitro 15:796-805; Bernuau et al, 1981, Biol. Cell 40:17-22) and albumin synthesis in cultured hepatocytes can be induced by certain ECM proteins (Michalopoulos et al, 1979, In vitro 15:796-805; Monomer et al, 1987, J. Cell Physiol. 130:221-227).
[0092] Likewise, hepatocytes functional heterogeneity has been described by a number of investigators and purportedly is influenced by several factors including: blood gas and
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LAI-2875394v7 nutrient gradients across the acinus (Matsumara et al , 1983, Amer. J. Physiol. 244:G656- 659), microenviromental differences (Martinez-Hernandez et al, 1993, In: Extracellular Matrix:Chemistry, Biology, Pathology, Zern and Reid, Eds. Marcel-Dekker, N. Y.), and maturational gradients of hepatocytes from the portal region (immature) to the terminal hepatic vein (mature) (Arber et al, 1988, Liver 8:80-87). The cultures of the present invention display a number of liver-specific functions for up to 7 weeks in culture, including TCDD-inducible cP450 enzyme activity. Although the three populations of hepatic cells that are resolved by flow cytometry all exhibit some ability to convert EFEE to fluorescein, and the highest activity is observed in the hepatocytes populations. [0093] The characteristics of cell growth on three-dimensional frameworks are intrinsically different from that on flat-bottomed plastic flasks. For example, the cell matrix deposition is enhanced, but proliferation rate is lower when microenviromental cells are cultured on nylon screens as compared to plastic flasks. This three-dimensional framework can also enhance the opportunity for normal cell-cell interactions and orientation, thereby permitting the various subpopulations of cells to act deterministically to form a tissue-like construct. In this regard, the presence of inhibitors in serum has been hypothesized as a potential reason why hepatocytes fail to proliferate in culture (Barnes and Sato, 1980, Cell 22:649-655) and serum factors have been reported to contribute to the appearance of the large, bizarre, and putatively de-differentiated masses of hepatocytes in monolayer cultures (Grisham, 1980, Ann. N.Y. Acad. Sci. 349:128-137; Hayner et al, 1988, Cancer Res. 48:368-378). These cells do not arise in nylon screen co-cultures, regardless of the length of the culture or the presence of serum in the medium. In addition, the serum conditioning that has been reported to adversely affect cP450 function in hepatocytes cultured on plastic flasks does not influence cP450 in the present model. The liver cultures disclosed herein are fed with SFM in order to eliminate nonspecific protein binding for ELISA assays but this medium lacks sufficient nutrients to maintain the cells for long term. The most obvious deficiency of this SFM is its inability to support microenviromental cells, which begin to die after about 48 h, an effect which is ameliorated but not completely abrogated by hydrocortisone supplementation.
[0094) PGA single fibers arranged into a felt are used in the working examples since it almost entirely degrades by 30 days in situ (Naughton et al, 1994, Hematol. Rev. 8:37-49).
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LAI-2875394v7 In other studies, constructs containing fiber bundles are found to persist for substantially longer periods. Fibroblastic compartmentalization of these constructs in vivo presents a tangible problem; connective tissue accumulation around the graft site can inhibit the movement of metabolites, thereby limiting the functional life of the graft (Naughton et al, 1992, Somat. Cell MoI. Gen. 18:451-462). The survival and function of grafts of hepatic PC:microenviromental cell co-cultures on PGA felt at various implantation sites in rats indicate that these constructs can be surgically implanted as tissue equivalents. The generation of hepatic structures, such as sinusoids and ductules implies that the cells are deterministic with respect to their formation of these structures; if all cell types that are normally present in a tissue are present in the culture/graft, they will re-establish their 'normal' orientation in vivo. The present invention also discloses the successful graft of liver tissue that is cultured in vitro.
[0095] During incubation, the three-dimensional liver cell culture system should be suspended in the nutrient medium. Cultures should be fed with fresh media periodically. Again, care should be taken to prevent cells released from the culture from sticking to the walls of the vessel where they could proliferate and form a confluent monolayer. The release of cells from the three-dimensional culture appears to occur more readily when culturing tissues, such as liver or bone marrow as opposed to structural tissues. As previously explained, should the released cells stick to the culture vessel and form a confluent monolayer, the proliferation of the three-dimensional culture can be 'shut down'. This can be avoided by removal of released cells during feeding, transfer of the three- dimensional culture to a new vessel, by agitation of the culture to prevent sticking of released cells to the vessel wall, or by the continuous flow of fresh media at a rate sufficient to replenish nutrients in the culture and remove released cells. In any case, the mature released cells could be collected and crypreserved for future use.
[0096] Growth factors and regulatory factors can be, but need not be added to the media since these types of factors are elaborated by the three-dimensional microenviromental cells. However, the addition of such factors, or the inoculation of other specialized cells can be used to enhance, alter or modulate proliferation and cell maturation in the cultures. The growth and activity of cells in culture can be affected by a variety of growth factors, such as insulin, growth hormone, somatomedins, colony stimulating factors, erythropoietin,
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LAI-2875394v7 epidermal growth factor, hepatic erythropoietic factor (hepatopoietin), and liver-cell growth factor. Other factors which regulate proliferation and/or differentiation include prostaglandins, interleukins, and naturally-occurring chalones.
[0097) Agents that increase the synthesis or formation of bile acids, particularly UDCA can be added to the media. Such agents include, but are not limited to, taurine, β-glucan, deuterium, glucocorticoid, dexamethasone, probucol, alpha-tocopherol, estradiol, progesterone, triidothyronine. See, e.g., Prince et ctl., 1989, Biochem J. 15(262):341-48; Lakeev et al, 1993, Biokhimiia 58(3):406-15; Chico et al, 1996, Exp. Clin. Endocrinol. Diabetes. 104(2): 137-44; Ellis et al, 1998, Hepatology 27(2):615-20.
6.1.6 Uses of the Three-Dimensional Cell Culture System
[0098] The three-dimensional culture system can be used in vitro to produce one or more biologically active molecules in high yield. For example, a cell which naturally produces large quantities of a particular biological product {e.g., a bile acid, a growth factor, regulatory factor, peptide hormone, antibody, etc.), or a host cell genetically engineered to produce a foreign gene product, could be clonally expanded using the three-dimensional culture system in vitro. In certain embodiments, the biologically active molecule is a bile acid, or its derivative, salt or conjugate or combination thereof. In some embodiments, the biologically active molecule is ursodeoxycholic acid ('UDCA') or its salt, conjugate or combination thereof.
[0099] If the cultured cell excretes the biologically active molecule into the nutrient medium, the conditioned medium can be used or the molecule can be readily isolated from the conditioned medium using standard separation techniques (e.g., HPLC, column chromatography, electrophoretic techniques). A 'bioreactor' can be used to take advantage of the continuous flow method for feeding the three-dimensional cultures in vitro. Essentially, as fresh media is passed through the three-dimensional culture, the molecule will be washed out of the culture along with the cells released from the culture. The biologically active molecule could be isolated (e.g., by HPLC column chromatography, electrophoresis, etc.) from the outflow of spent or conditioned media.
6.1.7 Recovery of the Conditioned Media
[00100] The cells can be cultured by any means known in the art. Preferably, the cells are cultured in an environment which enables aseptic processing and handling, continuous
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LAI-2875394v7 feeding cells and collecting media, or large scale growth. The media can be conditioned using, for example, an apparatus for cell culturing like that described in U.S. Pat. Nos. 5,763,267; 5,792,603, 5,827,729; 5,843,776, 5,846,828, 6,008,049, 6,060,306, 6,121 ,042, and 6,218,182, the disclosures of which are incorporated herein by reference. [00101] In some embodiments, the three-dimensional cell and tissue is cultured using an apparatus, such as described in U.S. Pat. Nos. 5,827,729, 6,008,049, 6,218,182, the contents of which are incorporated by references in their entireties. These patents disclose a system for maintaining and culturing three-dimensional tissues in vitro. Particularly, the system is provided with a bioreactor that has a tissue disposed between two media flows. The tissue is cultured on a porous substrate. A first media flow having a first concentration of solutes is in direct contact with one side of the tissue, and a second media flow having a second concentration of solutes is in direct contact with the opposing side of the tissue. The first concentration of solutes is different than the second concentration of solutes, creating a diffusional or osmotic pressure gradient which causes movement of solutes, including nutrients, through the tissue. The media flows can also be used to supply gases and growth factors to the cells in varying concentrations, depending on the needs of the particular tissue being cultured. Metabolic waste products, including carbon dioxide, are secreted into the media flows and carried away.
[00102] In some embodiments, the three-dimensional cell and tissue is cultured in a manner allowing for large scale growth (yielding large scale conditioned media) using, for example, an apparatus for aseptic large scale culturing like that described in U.S. Pat. No. 5,763,267 (the '267 patent), which is incorporated by reference herein in its entirety. Using the aseptic closed system described in the '267 patent, preconditioned culture media is transported from a fluid reservoir to an inlet manifold and evenly distributed to the cultures in a continuous flow system and is useful in culturing three-dimensional cell and tissue cultures, such as live cell cultures, for example. In particular, the apparatus described in the '267 patent includes a plurality of flexible or semi-flexible treatment chambers comprising one or more individual culture pockets, a plurality of rigid spacers, an inlet fluid manifold, an outlet fluid manifold, a fluid reservoir, and a means for transporting fluid within the system.
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LAI-2875394v7 [00103) During treatment, liquid medium is transported from the fluid reservoir to the inlet manifold, which in turn evenly distributes the media to each of the connected treatment chambers and internal culture pockets. An outlet fluid manifold is also provided to ensure that each treatment chamber is evenly filled and to ensure that any air bubbles formed during treatment are removed from the treatment chambers. The treatment chambers are flexible or semi-flexible so as to provide for easy end-user handling during rinsing and application of the cultured transplants. Due to the flexibility of the treatment chambers, rigid spacers are also provided which ensure even fluid distribution within the chambers during treatment. When appropriate (i.e., once the medium is conditioned so that extracellular proteins, such as growth factors have reached desirable levels in the medium), the 'conditioned' medium is pumped out of the system and processed for use. Preferably, the conditioned cell medium is harvested from the apparatus at the later stages of growth of the tissue when the level of certain growth factors and connective tissue protein secretion is at its highest level. In some embodiments, the medium conditioned by the three- dimensional cell culture is collected after exposure of the medium to the cells, for example, periodically at day 1 through day 14 of culturing.
[00104] In another embodiment, the three-dimensional tissue is cultivated in an apparatus for aseptic growth of three-dimensional tissue cultures as described in U.S. Pat. No. 5,843,766 (the '766 patent), incorporated herein in its entirety. The '766 patent discloses a tissue culture chamber in which the chamber is a casing that provides for growth of three- dimensional tissue that can be grown, preserved in frozen form, and shipped to the end user in the same aseptic container. The tissue culture chamber includes a casing comprising a substrate within the casing designed to facilitate three-dimensional tissue growth on the surface of the substrate. The casing includes an inlet and an outlet port which assist the inflow and outflow of medium. The casing also includes at least one flow distributor. In one embodiment, the flow distributor is a baffle, which is used to distribute the flow of the medium within the chamber to create a continuous, uniform piece of three-dimensional tissue. In a second embodiment, the flow distributor is a combination of deflector plates, distribution channels, and a flow channel. In each embodiment, the casing further includes a seal so as to ensure an aseptic environment inside the chamber during tissue growth and storage. Again the medium is preferably harvested from the apparatus at the later stages of
- 30 -
LAI-287S394v7 growth of the tissue when the level of in growlh factors and connective tissue protein secretion is at its highest level. In some embodiments, the medium conditioned by the three-dimensional cell culture is collected after exposure of the medium to the cells at days 1 through day 14 of culturing.
6.1.8 Concentration of the Conditioned Medium
[00105] Once the cell medium is conditioned, it can be used in any state. Physical embodiments of the conditioned medium include, but are not limited to, liquid or solid, frozen, lyophilized or otherwise dried into a powder. Additionally, the medium can be formulated with a pharmaceutically acceptable carrier as a vehicle for internal administration, applied directly to a food item or product, formulated with a salve or ointment for topical applications, or, for example, made into or added to surgical glue to accelerate healing of sutures following invasive procedures.
[00106] In certain embodiments, following removal of the cell conditioned medium, it may be necessary to further process the resulting conditioned medium. Such processing can include, but is not limited to, concentration by a water flux filtration device or by defiltration using the methods described, e.g., in Doyle et ah, Cell &Tissue Culture. Laboratory Procedures in Biochemistry (1st Ed., 1994) John Wiley and Sons, pp 29 D:0.1 29 D:0.4.
[00107] Additionally, the medium can be concentrated, e.g., 10-fold to 20-fold using a positive pressure concentration device having a filter with a 10,000 ml cut-off (Amicon, Beverly, MA.).
[00108] Also, the conditioned medium can be further processed for removing undesirable components, such as protease and for isolation of a biologically active molecule of interest. The methods used for isolation and purification of biologically active molecules are such that the optimal biological activity is maintained, and will be readily apparent to one of ordinary skill in the art. Exemplary methods include, but are not limited to, gel chromatography (using matrices, such as sephadex) ion exchange, metal chelate affinity chromatography with an insoluble matrix, such as cross-linked agarose, HPLC purification and hydrophobic interaction chromatography of the conditioned media. Such techniques are described in greater detail, e.g., in Doyle et ah, Cell &Tissue Culture. Laboratory Procedures in Biochemistry (1st Ed., 1994) John Wiley and Sons. Of course, depending
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LΛI-2875394v7 upon the desired application of the conditioned medium, and/or products derived thereof, appropriate measures must be taken to maintain sterility. Alternatively, sterilization can be necessary and can be accomplished by methods known to one of ordinary skill in the art, such as, for example, heat and/or filter sterilization taking care to preserve the desired biological activity.
[00109] The biologically active molecule can be isolated from the collected culture medium by any method or technique according to the judgment of those of skill in the art. For example, bile acid synthesis and formation in cell culture medium can be measured by any methods known to those of skill in the art, including, but not limited to, capillary gas- liquid chromatography, enzymatic-bioluminescence assay, gas chromatography-mass spectrometry, anion exchange chromatography. See, e.g., Whiting et al. , 1989, Biochim Biophy Acta 1001(2): 176-84; Princen et ai, 1989, Biochem. J. 262:341-48; Bjorkhem et al., 1983, Scand. J. Clin. Lab. Invest, 43:163-170; Einarsson et al. 2000, World J. Gastroentero 6(4):522-25; Kren et al, 1995, Am J. Physiol. 269:961-973.
[00110] Biological activities of molecules, such as bile acids, can be measured by any methods known in the art. For example, the effect of bile acids on limiting cell apoptosis can be measured, e.g., as described in detail in U.S. Pat. No. 6,544,972, the contents of which is incorporated by reference in its entirety.
6.2 COMPOSITIONS AND USES THEREOF
[00111] In one aspect, the present invention provides a composition comprising a biologically active molecule produced by a three-dimensional cell and tissue culture system as described above. The composition of the invention can be the conditioned medium itself, an extract, subset or concentrate of the conditioned medium, a combination of the conditioned medium and an appropriate carrier, or a composition comprising a biologically active molecule isolated from the conditioned medium.
[00112] In certain embodiments, the biologically active molecule is a bile acid, or its derivative, salt or conjugate thereof. The bile acid can be any bile acid known in the art, including, but not limited to, deoxycholic acid, cholic acid, taurocholic acid, glycocholic acid, glycodeoxycholic acid, taurodeoxycholic acid, ursodeoxycholic acid and/orchenodeoxycholic acid.
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LΛI-2875394v7 P T/US2009/004038
[00113] Λ bile acid conjugate is a bile acid in which a substituent (e g . gly cine, taurine, glucuronate, sulfate or other substituent) is attached to the side chain of carboxylic acid or to one of the ring hydroxyl groups via an ester, ether, or amide linkage. 100114] UDCΛ has the formula:
Figure imgf000035_0001
and the full chemical name 17 β-(l-methyl-3-carboxypropyl)etiocholane-3α, 7βdiol. No major toxicity is known to be associated with UDCA (W. H. Bachrach et al, Dig. Dis. ScL, 30, 642 (1985)); The Merck Index (1 lth ed. 1989) at 1556. TUDCA is taurine conjugate of UDCA.
[00115] In specific embodiments, the biologically active molecule is ursodeoxycholic acid (UDCA) or its derivative, salt or conjugate thereof. In other embodiments, the biologically active molecule is a UDCA conjugate, such as its taurine conjugate, TUDCA. In certain embodiments, the composition comprises more than 5%, 10%, 25%, 50%, 75%, 90%, 95% or 99% (w/v) of the biologically active molecule, such as a bile acid (e.g., UDCA or TUDCA).
6.2.1 Uses of the Compositions
[00116] The present invention also provides uses of the compositions comprising a biologically active molecule derived from a conditioned culture medium using a three- dimensional cell and tissue culture system. [00117] Food Additives And Dietary Supplements
[00118] The compositions of the invention can be used as food additives and/or formulated into dietary supplements. The conditioned media of the invention contains many useful biologically active molecules in an abundance and variety not found in individual foods or food groups. The composition can be sterile and free from contamination by human pathogens (i.e. , aseptic). The composition can be concentrated and/or lyophilized and preferably administered in capsules or tablets for ingestion. Alternatively, the compositions can be directly added to adult or baby food to enhance nutritional content or to reduce blood lipid or cholesterol levels.
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LAI-2875394v7 J001 19J Pharmaceutical Applications
[001201 In other embodiments, the compositions are used for pharmaceutical applications for treating a disease or condition, such as by alleviating one or more symptoms of the disease or condition, in subject in need thereof. Thus, the present invention provides a method for treating a disease or condition in subject in need thereof comprising administering an effective amount of a composition produced by the method described herein.
[00121] The diseases or conditions include but are limited to liver or gallbladder diseases, diseases relating to lipid or cholesterol hemeostasis, degenerative diseases or disorders, cardiovascular or cerebrovascular diseases or inflammatory diseases.
[00122] Since the middle 1980s, UDCA was approved for use for gallstone dissolution and subsequently for the treatment of chronic cholestatic liver diseases. See, e.g.,
Rodrigues et al. 2001, Expert. Opin. Investig. Drugs. 10(7): 1243-1253. Thus, in certain embodiments, the compositions of the present invention are used for the treatment of various liver or gallbladder diseases, or a symptom thereof. Liver or gallbladder disorders include but are limited to cholestasis disease, gallstone or choleliths, cirrhosis, primarily biliary cirrhosis, sclerosing cholangitis, steatoheptitis, biliary atresia, hepatitis, jaundice, intrahepatic cholestatsis of preganancy, cystic fibrosis-associated liver disease, chronic graft- versus host disease of the liver or cholestatic diseases.
[00123] Bile acids also play an important role in regulating cholesterol homeostasis and lipid hemeostasis. Thus, in other embodiments, the compositions of the present invention are used in the treatment of diseases relating to lipid or cholesterol hemeostasis. Such diseases include, but are not limited to, dyslipidemia (e.g., hyperlipidemia) or dyscholesterolemia (e.g., hypercholesterolemia).
[00124] Mitochondrial dysfunction and subsequent oxidative damage have been implicated in the pathogenesis of several neurobiological disorders, such as ischemic neuronal injury and chronic neurodegenerative disease. See, e.g., Nathanson et al., 1991,
Hepatυlogy, 14:551 -566. It was initially described that neuronal cell death associated with these disorders was necrotic in nature but recent studies suggest that apoptotic cell death can have a role in the pathogenesis of these disease.
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LΛI-2875394v7 [00125] It has been reported recently that TUDCΛ can inhibit the mitochondrial perturv ations associated with the apoptosis response induced by various agents, e.g., okadaic acid, deox>holic acid, transforming growth factor βl etc. See, e.g., U.S. Pat. No. 6.544,972. Thus, in certain embodiments, the compositions of the present invention are used in inhibiting apoptosis of a mammalian cell comprising contacting the cell with an effective amount of the composition produced by the methods described herein. The apoptosis can be induced by a nonmembrane damaging agent, e.g., TGF βl , anti-Fas antibody and okadaic acid.
[00126] In some embodiments, the compositions of the present invention are used in the treatment of a disease or condition associated with increased levels of apoptosis as a pathogenesis of the disorder. Such diseases or conditions include, but are not limited to, degenerative, cardiovascular or cerebrovascular diseases, or injuries of the nervous system. Exemplary degenerative diseases include, but are not limited to, glaucoma, Huntington's disease, Parkinson's disease, Alzheimer's disease, retinal degeneration. Cardiovascular or cerebrovascular diseases include, but are not limited to, stroke, myocardial infarction, atherosclerosis.
[00127] In other embodiments, the compositions of the present invention are used to treat injuries of the nervous system associated with hemorrhage, for example, a hemorrhagic stroke, a head trauma, a spinal cord injury or a peripheral nerve injury. [00128] In yet other embodiments, the compositions of the present invention are used to alleviate spasms and delirium caused by extensive burns, reduce swelling, inflammation and pain in trauma, sprains, fractures or hemorrhoids.
[00129] In some embodiments, the compositions of the present invention comprise a pharmaceutically acceptable carrier. The term 'pharmaceutically acceptable' means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans. The term 'carrier' refers to a diluent, adjuvant (e.g. , Freund's adjuvant (complete and incomplete)), excipient, or vehicle with which the therapeutic is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water is a preferred carrier when the
- 35 -
LAI-2875394v7 pharmaceutical composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. Examples of suitable pharmaceutical carriers are described, for example, in Remington's Pharmaceutical Sciences ( 18lh Ed., 1995). [00130J Typical pharmaceutical compositions and dosage forms comprise one or more excipients. Suitable excipients are well-known to those skilled in the art of pharmacy, and non-limiting examples of suitable excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. Whether a particular excipient is suitable for incorporation into a pharmaceutical composition or dosage form depends on a variety of factors well known in the art including, but not limited to, the way in which the dosage form will be administered to a patient and the specific active ingredients in the dosage form. The composition or single unit dosage form, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents.
[00131] Lactose-free compositions of the invention can comprise excipients that are well known in the art and are listed, for example, in the U.S. Pharmocopia (USP) SP (XXI)/NF (XVI). In general, lactose-free compositions comprise an active ingredient, a binder/filler, and a lubricant in pharmaceutically compatible and pharmaceutically acceptable amounts. Exemplary lactose-free dosage forms comprise an active ingredient, microcrystalline cellulose, pre-gelatinized starch, and magnesium stearate
[00132] The composition can be formulated into pharmaceuticals in the form of tablets, capsules, skin patches, inhalers, eye drops, nose drops, ear drops, suppositories, creams, ointments, injectables, hydrogels and into any other appropriate formulation known to one of skill in the art. For oral administration the pharmaceutical compositions can take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable carrier or excipients, such as binding agents (e.g., pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrants (e.g., potato starch or sodium starch glycolae); or wetting agents (e.g., sodium lauryl sulphate). Tablets can be coated using
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LΛI-2875394v7 methods well known in the art. Liquid preparations for oral administration can take the form of, for example, solutions, syrups or suspensions, or they can be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations can be prepared by conventional means with pharmaceutically acceptable additives, such as suspending agents (e.g., sorbitol syrup cellulose derivatives or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g. , almond oil, oily esters, ethyl alcohol or fractionated vegetable oils); and preservatives (e.g., methyl or propyl-p-hydroxybenzoates or sorbic acid). The preparations can also contain buffer salts, flavoring, coloring and sweetening agents as appropriate. [00133] The composition of the invention can be delivered to a patient via a variety of routes using standard procedures well known to those of skill in the art. For example, such delivery can be site-specific, oral, nasal, intravenous, subcutaneous, intradermal, transdermal, intramuscular or intraperitoneal administration. Also, they can be formulated to function as controlled, slow release vehicles.
(00134) Assays commonly employed by those of skill in the art can be utilized to test the activity of the particular biologically active molecule, such as UDCA, thereby ensuring that an acceptable level of biological activity (e.g., a therapeutically effective activity) is retained by the compositions
[00135] The therapeutically effective doses of any of the biologically active molecules can routinely be determined using techniques well known to those of skill in the art. See, e.g., Physician's Desk Reference (59th Ed., 2005), Thomas Healthcare; Remington's Pharmaceutical Sciences (18th Ed., 1995) Mack Publishing Co., Easton, PA; Goodman & Gilman's The Pharmacological Basis of Therapeutics (1 1th Ed., 2005), McGraw Hill Professional. A 'therapeutically effective' dose refers to that amount of the compound sufficient to result in amelioration of at least one symptom of the processes and/or diseases being treated.
[00136] The data obtained from the cell culture assays and animal studies can be used in formulating a range of dosage for use in humans. The dosage of such compounds lies preferably within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage can vary within this range depending upon the dosage form employed and the route of administration utilized. For any compound used in the method of the
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LΛI-2875394v7 invention, the therapeutically effective dose can be estimated initially from cell culture assays. A circulating plasma concentration range that includes the IC50 {i.e., the concentration of the test compound which achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to more accurately determine useful doses in humans. Levels in plasma can be measured, for example, by high performance liquid chromatography.
7. EXAMPLE:
7.1 MATERIALS AND METHODS 7.1.1 Perfusion and cell isolation
[00137] Male Long-Evans rats (6-9 weeks of age) were anesthetized with 0.3 ml of injectable sodium pentobarbital intraperitoneally and subjected to a series of prograde perfusions through the portal vein using: Ca2+ -free buffer (500 ml) (Pertoft and Smedsrod, 1987, In: Cell Separation: Methods and Selected Applications. Vol. 4, Academic Press, New York, pp. 14), buffer containing Ca2+ and 0.05 g/dl type IV collagenase (100 ml)(Sigma Chemical Co, MO.), and buffer conditioned with 10% fetal bovine serum (FBS) (50 ml). Medium was perfused at a flow rate of 50 ml/min using a Harvard Instruments (MA) peristaltic pump. Hepatocytes were liberated into suspension, filtered through a 185 μm nylon sieve, pelleted by centrifugation, and resuspended in complete medium. [00138] Hepatic cells were separated into various subpopulations using either a two-step 'PERCOLL' gradient centrifugation (Naughton et al., 1991, In: In vitro Toxicology, Vol. 8, Mechanisms and New Technology, Mary Ann Liebert, Inc., New York) or a pre-formed continuous gradient. Briefly, neat 'PERCOLL' stock solution was diluted to 70% (v/v) with IX Dulbecco's phosphate buffered saline (DPBS). The cell suspension was overlaid and spun at 1200 x g for 15 min at 10° C. in an IEC swing bucket centrifuge to remove cellular debris and erythrocytes. The remaining cells were resuspended in DPBS and layered atop a 25% : 50% discontinuous 'PERCOLL' gradient and centrifuged as in the first step. Alternatively, a 30% 'PERCOLL' solution was spun at 30,000Xg for 30 min in a Sorvall RCB5 centrifuge with a 20° fixed angle rotor to form a continuous gradient. Suspensions of hepatic cells were overlaid and centrifuged at 200Xg for 15 min at 10° C. The densities of the various isolation zones were determined using density marker beads
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LAI-2875394v7 and cytosmear preparations of cells of each zone were stained with DIFF-QUIK (Baxter, IL).
7.1.2 Nylon Screen Culture
[00139] 15 mmX60 mm nylon filtration screens (Tetko, NY) were treated with 1.0 M acetic acid, washed in distilled water, and soaked in FBS to enhance cellular attachment. These were placed in Tissue Tek slide chambers (Nunc, Inc., IL) and inoculated with 107 liver microenviromental cells that were expanded in monolayer culture for 3-4 passes. Screens were transferred to 25 cm' flasks 18-24 h later. Within 10 days, projections of developing microenviromental cells extended across 3 to 4 out of every 5 mesh openings. Screen cultures were placed in slide chambers, inoculated with 2-5X10 hepatic hepatocytes or acidophilic reserve cells, and transferred to 25 cm2 flasks after 18-24 h. Cells were cultured (5% CO2 /35°-37°C./>90% humidity) in DMEM conditioned with 6% FBS and 10% equine serum and supplemented with 10 ng/ml glucagon, 10 μg/ml insulin (Sigma Chem. Co., MO), 10 μg/ml glucose, and 10'7 M hydrocortisone hemisuccinate. Complete medium replacement was performed 4-5 times per week.
7.1.3 Analysis Of Bile Acids
[00140] Bile acids from the liver cell culture can be analyzed by any method known in the art, for example, as described in Einarsson et al, 2000, World J. Gastroentero. 6(4): 522-525; Ellis et al, 1998, Hepatology 27:615-620. Briefly, deuterium-labeled bile acids are added to the collected culture medium. The medium, together with internal standards, is diluted with aqueous ethanol (1/1 vol/vol) and hydrolyzed at 1250C for 12 hours using potassium hydroxide (1 mol/1). The hydrolyzed mixture is diluted with saline and extracted with ether. The ether phase is washed with water until neutral. The solvent is evaporated and the residue is methylated with diazomethane. The methylated extract is then converted into trimethysilyl ether derivatives with hexamethyl-silazane and tricholrosilane and further analyzed by gas chromatography/mass spectrometry.
7.1.4 ELISA Assays
[00141] (a) Albumin. Medium collected at each feeding was assayed for rat albumin using the enzyme-linked immunosorbent assay (ELISA). Reagents were purchased from Cappel Inc, (NC). 100 μl of spent medium was added to 96 well plates and stored at 0° C.
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LAI-2875394v7 for 12-14 h. The wells were washed with 0.05% Tween-20 in PBS and non-specific binding sites were blocked with 5.0% bovine serum albumin (BSA)(Miles Inc., IL) in PBS. After washing with 0.05% Tween-20, 100 μl of peroxidase-conjugated sheep anti-rat albumin was added to each well and incubated for 1 hr at 22° C. The wells were washed with 0.05% Tween-20 and incubated for 15 min with O-phenylenediamine substrate. The reaction was stopped and absorbance at 490 run was measured with a kinetic microplate reader (Molecular Devices Inc., CA). Results were calculated from a standard curve constructed using chromatographically-pure rat albumin.
[00142] (b) Fibrinogen, fibronectin, and transferrin. Because of the lack of suitable species-specific antibodies for these proteins, liver cultures were transferred to serum-free medium (SFM) for 24 h prior to collection of supernatant samples. The SFM formulation of Enat et al (Enat βt al. , 1984, Proc. Nat. Acad. Sci. USA 81 : 141 1 - 1415) was modified by supplementing with hydrocortisone hemisuccinate (50 μg/ml), fungizone (0.5 μg/ml), penicillin (5 U/ml), and streptomycin (5 μg/ml). After 24 h in SFM, cultures were returned to complete medium and samples were stored at -20° C. until assayed. SFM was used as a negative control and affinity-purified proteins including rat fibrinogen (Sigma), rat fibronectin (Chemicon), and rat transferrin (Cappel Inc., NC) were diluted from 7.8125 ng/ml to 1 μg/ml for a standard curve. All supernatant samples were tested undiluted, in quadruplicate. 50 μl of control, standard or supernatant were added to each well of a 96 well plate and incubated 15 h at 4° C. Wells were blocked with 0.5% BSA in PBS, for 1 h at 37° C. and washed with 0.05% Tween-20 in PBS. 50 μl of peroxidase-conjugated antibodies, such as anti-human fibrinogen, anti-human fibronectin and anti-rat transferrin (The Binding Site, Ltd., Calif.) were added to each well, incubated for 1 h at 37° C, and washed with PBS/Tween-20. 50 μl of K-Blue peroxidase substrate (Elisa Technologies, KY) were added to each well. Plates were incubated at .about 35° C. for 10 min in the dark, and read on a Dynatech plate reader at 650 nm. 7.1.5 Flow Cytometry
[00143] (a) Phenotypic Analysis. Freshly isolated liver cells and cells derived from liver cultures were reacted on ice with 100 μl mouse monoclonal IgGi polymorphic antibodies to either rat MHC I or MHC II antigens which were conjugated to fluorescein isothiocyanate (FITC) (Serotec Inc., UK). Control cells were treated with mouse IgGi -FITC alone. The
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LΛI-2875394v7 samples wore analyzed using an EPICS C flow cytometer (Coulter Electronics, FL) tuned to a wavelength of 488 nm w ith the fluorescence gain adjusted to exclude >98% of the control cells. Windows were established around the various cell populations using the forward light scatter (FLS) vs. side scatter (SS) two parameter histogram and the percentage of positively fluorescent events was determined.
[00144] (b) Cytochrome P-450 (cP450 ) assay. Cells were analyzed for evidence to cP450 enzyme activity by quantifying incremental fluorescein fluorescence in cells accumulating ethoxyfluorescein ethyl ester (EFEE) (Miller, 1983, Anal. Chem. 133:46-57; White et al, 1987, Biochem. J. 247:23-28). EFEE to fluorescein conversion occurs via the specific cleavage of an ether linkage by a polycyclic aromatic hydrocarbon (PAH)-induced cP450 (Miller,, 1983, Anal. Chem. 133:46-57). As with other cP450 -catalyzed reactions, EFEE metabolism requires NADPH, and can be inhibited by carbon monoxide or monoclonal antibodies that decrease PAH or benzo(a)pyrene metabolism (Miller., 1983, Anal. Chem. 133:46-57). At 18 h prior to cP450 assay, cells were induced with 1 nM of a 1 μM stock solution of the non-fluorescent compound, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (Chemical Carcinogen Repository, National Cancer Institute, Kansas City, MO) in dimethylsulfoxide (DMSO) (Sigma Chem. Co.). Cultured cells were lifted using a dispase- collagenase mixture, pelleted and resuspended in phosphate buffered saline (PBS) at a density of .about.5 XlO5 cells/ml, stored on ice for 1 h, and gradually warmed to 37° C. Cells were incubated with 50 nM EFEE (Molecular Probes, OR) in PBS for 5 min at 37° C. and examined for green fluorescence on a flow cytometer with a 515 nm long-pass filter and tuned to the 488 nm band. Fluorescence resulting from EFEE to fluorescein conversion was gated on various populations of cells based on differences in FLS vs. SS characteristics and was measured once/minute for up to 25 min in samples maintained at 37° C. [00145] (c) Statistical Analysis. Flow cytometry measurements were taken in triplicate on samples sizes of 5,000 (phenotypic analysis) events. EFEE to fluorescein conversion was measured as a function of time with 3,000 to 5,000 events being sampled per min. for up to 20 min. All results are expressed as x±l sem. Levels of significance (P) were determined using Student's T test. Data were considered significant at the 5% level.
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LAI-2875394v7 7.1.6 Cell Counts/Identification
[00146] Total non-adherent and adherent zone cell counts were determined using a Coulter Model ZM cell counter. Differential cell counts were based strictly on the morphology of cells stained using Diff-Quik (Baxter SP, IL). Phagocytosis of colloidal carbon and reaction with FITC-conjugated antibodies to the vW factor VIII segment were used initially to identify Kupffer cells and vascular endothelial cells, respectively.
7.1.7 lmmunochemistry
[00147] Specimens were fixed with 10% formalin in PBS, dehydrated in a graded series of ethanols, cleared with Hemo-De (Fisher Scientific, NJ), embedded in paraffin at 56° C, and sectioned at 5 μm. Sections were cleared in xylene, re-hydrated in a series of ethanols, and predigested with 0.5 mg/ml bovine testicular hyaluronidase in 0.1 N sodium acetateacetic acid buffer at pH=6.0 (Sigma Chem Co., MO). Slides were blocked with a solution of 4% goat serum, 0.1% BSA, and 0.1% Tween-20 in 0.1 M NaCl. Polyclonal rabbit primary antibodies to fibronectin, collagen type III, laminin (Telios Pharmaceuticals, CA), transferrin, albumin, or fibrinogen (Cappel Inc., NC) were reacted with the sections for 1-3 h at 22° C, washed in 0.1% Tween-20 in 0.1 M NaCl, placed in Tris buffer for 10 min, and labelled with goat anti-rabbit IgG-FITC for 30 min at 22° C. prior to viewing on a Nikon Epifluorescence microscope. Enzyme digested serial sections also were reacted with monoclonal antibodies to rat cytokeratin 19 (Chemicon International Inc., CA) for 90 min at 37° C, washed, and incubated with sheep anti-mouse IgG-FITC for 30 min. Photographs were obtained using a Nikon Optiphot fluorescence microscope. 7.2 RESULTS
7.2.1 Liver Cell Isolation
[00148] The various types of hepatic cells, their relative densities, and method of isolation are listed in Table II.
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I.AI-2875394v7 [00149] TABLE Il - Isolation characteristics of various liver cells*.
Figure imgf000045_0001
*Separations performed at osmolality of 360-370 mOsM
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LAI-2875394v7 [00150] Two major cell groups were identified in these preparations: [00151 ] (a) Hepatocytes. Three types of hepatocytes were observed based on their morphological characteristics:
[00152] T) pe I. These were small (15-20 μm) mononuclear hepatocytes with deep cytoplasmic basophilia. These were relatively dense, attached poorly to preestablished microenviromental cells and did not adhere directly to plastic, and did not proliferate in vitro in association with either substratum.
[00153] Type II. These were moderately sized (20-30 μm) binuclear cells with 1-2 nucleoli and moderate to deep cytoplasmic basophilia (FIG. IA). Some of these cells adhered to plastic and some Type I hepatocytes attached to them. They proliferated for 2-3 days after plating in monolayer culture and then became mitotically inactive. [00154] Type III. These large (>35 μm), ghost-like cells (FIG. 1 B) were usually binuclear with 2-3 very prominent nucleoli per nucleus, accumulated little or no basic stain in the cytoplasm and displayed buoyant densities similar to hepatic microenviromental cells although their volume was substantially greater than these cells. These 'acidophilic' hepatocytes adhered rapidly and firmly to plastic, had a much higher mitotic activity than other liver cells, and retained this mitotic activity for 10-14 days in monolayer culture. Such large acidophilic cells represent a population of highly mitotic liver reserve cells. Although virtually all of these cells adhered, all gradually detached from the plastic within 2-3 weeks and assumed the appearance of type II cells. In addition, Type I and Type II hepatocytes attached to pre-established monolayers of acidophilic cells. [00155] Although some Type I, II, and III hepatocytes weakly expressed MHC I antigens, these were not detectable on most hepatocytes cells. Hepatocytes did not express MHC II antigens.
[00156] (b) Microenviromental cells. This population of hepatic cells included fibroblasts, vascular and biliary endothelia, adipocytes, and Kupffer cells that were co- separated by centrifuging freshly prepared cells against a 70% 'PERCOLL' gradient in 1OX PBS (density=l .09 gm/ml) for 10 min forming a pellet and a central zone. Cells from the central zone were washed and centrifuged on a 25%/50% 'PERCOLL' column. Microenviromental cells were localized in the interface zone (density=l .03625 g/ml). This isolate also contained small numbers of peripheral blood leukocytes. The small size of
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LΛI-2875394v7 microenviromental cells as compared to hepatocytes (FIG. I A) permitted a relatively simple differentiation of these cell types. However, the individual subpopulations of liver microenviromental cells were less distinct from each other based purely on morphological parameters. Whereas fibroblasts and adipocytes were identified morphologically, Kupffer cells and endothelial cells were differentiated by their ability to phagocytose colloidal carbon or be recognized by a monoclonal antibody to vW factor, respectively. Moderate levels of MHC I antigens were detected on all of these microenviromental cell subsets; Kupffer cells and endothelia were the only stroma to express MHC II antigens.
7.2.2 Characterization Qf Suspended Liver Cell Nylon Co-Cultures
[00157] When hepatocytes were inoculated onto nylon screens containing preestablished microenviromental cells, they grew in clusters for the first 1-2 weeks of culture (FIG. 2A); patterns of cell growth were increasingly more difficult to discern after this time because of the high cell density of the framework. The screen itself was composed of nylon fibers that were 90 μm in diameter and arranged into a square weave pattern with openings of 140 μmX140 μm. The total volume for cell growth within each of these spaces was .about.1.8 m3. The sections shown in FIG. 2B and 2C depict the field across one of these screen openings. Microenviromental cells and their processes are the major elements of the field at several hours after the inoculation of the microenviromental tissue with hepatocytes (FIG. 2B). With time the hepatocytes eventually filled in most of the available spaces seen in this section. The section of a 52 day old culture (FIG. 2C) shows a screen space that is tightly packed with large, round PC. The process of filling in this framework was generally complete by 4-6 weeks of co-culture.
[00158] Although the radiothymidine incorporation data (FIG. 3A) did not discriminate between hepatocytes and microenviromental cells, it was apparent upon comparison with the absolute adherent cell count and differential counts (FIG. 3B) that the nylon screen framework had a fixed capacity for cell growth, i.e., about 107 for liver cells. Tritiated thymidine incorporation into DNA decreased as the spaces filled in with growing liver cells and the absolute number of cells plateaued. Differential counts of adherent zone cells revealed increases in the numbers of hepatocytes as well as microenviromental cells with time in vitro (FIG. 3B) but the numbers of hepatocytes remained higher than microenviromental cell counts for the duration of the experiment. The PC, which were
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LΛI-2875394v7 9 004038
considerably larger cells occupied most of the area in the cultures, hepatocytes in the suspended nylon screen co-cultures displayed a rounded, as compared to the spread/flat morphology that was typical of hepatocyte culture on plastic flasks. These round cells stained positively for albumin using the immunoperoxidase method (FIG. 4A) and for fibrinogen, transferrin, and fibronectin by immunofluorescence. They also stained positively for cytokeratin 19, an epithelial cell marker found on hepatocytes (FlG. 4B). By comparison, the thinner microenviromental cells that interweaved between the hepatocytes in these cultures did not express liver-specific proteins but did stain positively for laminin and collagen type III as well as fibronectin (Table III). Co-cultures established with >85% homogeneous populations of acidophilic hepatocytes exhibited higher seeding efficiencies and rates of cluster formation than co-cultures inoculated with mixed hepatocytes populations but were not superior in terms of functional activity.
[00159) TABLE III - Immunofluorescence detection of various antigens in hepatocytes and/or matrix of liver co-cultures or sections of adult liver tissue.
Figure imgf000048_0001
[00160] Hepatocytes derived from suspended nylon screen co-cultures displayed TCDD- inducible cP450 enzyme activity for up to 56 days as indicated by their ability to transform EFEE to fluorescein (FIG. 5A and 5B). Since the flow cytometer was gated on discrete populations of cells based upon their physical characteristics (FLS vs. SS), the EFEE to fluorescein conversion was quantified at the cellular level and leakage of fluorescein from the cell to the medium did not influence this measurement. Peak EFEE to fluorescein conversion was >2 times higher in the 17, 26, 41, or 58 day co-cultures than in either freshly
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LΛl-2875394v7 isolated liver cells or 24 h suspension cultures of these hepatocytes (FIG. 5B). Although peak fluorescence was not contingent upon the age of the co-culture, different rates of EFEE conversion were observed in cultures of different ages. In addition, the EFEE conversion kinetics of TCDD-primed cells varied depending on the concentration of substrate; transformation of EFEE to fluorescein and subsequent egress from the cells was complete by 14 min at EFEE levels of 2.5 μl/ml and 5 μl/ml whereas metabolism of 7.5 μl/ml of EFEE stock solution did not drop to baseline levels until 23 min after addition of substrate to 58 day old cultures. Although cP450 activity was observed in Kupffer cells and in hepatocytes of various sizes, moderate to large hepatocytes displayed the highest EFEE to fluorescein conversion. Arbitrary conversion units were calculated as the product of the percent positive fluorescence and peak channel number as described by Miller (Miller, 1983, Anal. Chem. 133:46-57). This provided an index of the percentage of cells having cP450 activity and the strength of their activity.
[00161] Although the levels of albumin, fibrinogen, transferrin, and free fibronectin in the medium varied, all were present in the culture medium for up to 48 days (FIG. 6 and FIG. 7). Fibrinogen concentration in the culture medium actually increased over time in culture from <50 ng/ml for the first 20 days of culture to > 150 ng/ml by 28 days, where it remained for the last 3 weeks of the study. Fibronectin levels increased for up to 40 days but dropped by about 75% by 48 days in vitro. A similar pattern was observed for albumin which was present at peak level at 25 days and dropped by about 25% thereafter to a titer that was constant for the remainder of the experiment. In contrast, transferrin synthesis declined steadily for the first 2 weeks of culture to a level of about lμg/ml that was relatively stable over the next 4 weeks in vitro. Cultured hepatocytes manifested a diminished expression of class I MHC antigens when compared to freshly isolated hepatic parenchyma (2.6 % vs. 4.9%, respectively). In contrast, no MHC class I antigen expression was detectable on microenviromental cells and MHC class II epitopes on macrophagic cells were substantially lower than on non-cultured cells (3.5% vs. 9.6% respectively). 7.2.3 Analysis of Bile Acids in The Culture Medium
[00162] Formation of bile acids in the culture medium can be determined, by anion exchange chromatography and gas chromatography-mass spectrometry, such as described in Einarsson et cil. 2000, World J. Gastroentero 6(4):522-25, the contents of which are
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LAI-2875394v7 incorporated by reference in its entirety. Deuterium-labeled bile acids can be added to the collected culture medium. Alter alkaline hydrolysis and extraction using acidic ether, the bile acids are analyzed by gas chromatography-mass spectrometry.
7.2.4 The Anti-Apoptotic Activity Of The Composition
[00163] The effect of the composition comprising UDCA or TUDCA on cell apoptosis can assessed, e.g., using the method described in U.S. Pat. No. 6,544,972, the content of which is incorporated by reference in its entirety. Briefly, Huh-7 cells, HepG2 cells or primary rat hepatocytes can be cultured and incubated with the composition produced in the above example for 2 hours. Then the cell can be treated with TGF-βl, 50 nM okadaic acid (Boehringer Mannheim Biochemicals, Inc, Indianapolis, Ind.), Fas ligand, or no addition for 48 h. Morphological evaluation of apoptosis and the annexin V-biotin apoptosis assay can be performed. The results show that the UCDA composition produced in the example above can inhibit apoptosis induced by TGF-βl, okadaic acid, and Fas ligand. [00164] The present invention is not to be limited in scope by the exemplified embodiments, which are intended as illustrations of individual aspects of the invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims. [00165] All publications cited herein are incorporated by reference in their entirety.
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I.ΛI-2875394v7

Claims

WHAT IS CLAIMED:
1. A composition comprising a bile acid derived from a cell culture medium conditioned by hepatocytes in three-dimensional culture.
2. A composition comprising a bile acid isolated from a cell culture medium conditioned by hepatocytes cultured on a living microenviromental cell tissue prepared in vitro, wherein the living microenviromental cell tissue
(a) comprises microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells, and
(b) is attached to and substantially envelopes a framework comprising a biocompatible, non-living material formed into a three-dimensional structure having interstitial spaces bridged by the microenviromental cells, wherein the hepatocytes proliferate and secrete the bile acid into the conditioned medium.
3. A composition comprising a bile acid, wherein the composition is the product of a process comprising:
(a) inoculating hepatocytes onto a living microenviromental cell tissue prepared in vitro, wherein the living microenviromental cell tissue
(i) comprises microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells, and
(ii) is attached to and substantially envelopes a framework comprising a biocompatible, non-living material formed into a three-dimensional structure having interstitial spaces bridged by the microenviromental cells;
(a) incubating the inoculated living microenviromental cell tissue in a medium so that the inoculated cells proliferate in culture;
(b) collecting the medium; and
(c) isolating the bile acid.
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LAI-2875394v7
4. The composition of any one of claims 1 -3, wherein the bile acid is a derivative of a bile acid, a salt of a bile acid or a conjugate of a bile acid, or any combination thereof.
5. The composition of any one of claims 2-4, wherein the microenviromental cells are fibroblasts.
6. The composition of claim 5, wherein the microenviromental cells further comprise endothelial cells, pericytes, macrophages, monocytes, leukocytes, plasma cells, mast cells, adipocytes or any combination thereof.
7. The composition of any one of claims 2-4, wherein the framework comprises a biodegradable material.
8. The composition of claim 7, wherein the biodegradable material is cotton, polyglycolic acid, cat gut sutures, cellulose, gelatin or dextran.
9. The composition of any one of claims 2-4, wherein the framework is composed of a non-biodegradable material.
10. The composition of claim 9, wherein the non-biodegradable material is a polyamide, polyester, polystyrene, polypropylene, polyacrylate, polyvinyl, polycarbonate, polytetrafluorethylene, or nitrocellulose compound.
1 1. The composition of any one of claims 7-10, wherein the framework is pre-coated with collagen or other extracellular matrix.
12. The composition of any one of claims 2-4, wherein the framework is a mesh.
13. The composition of any one of claims 2-4, wherein the medium comprise an agent that increases bile acid synthesis.
14. The composition of any one of claims 1 -4, wherein the hepatocytes are mammalian hepatocytes.
15. The composition of claim 14, wherein the mammalian hepatocytes are bear hepatocytes.
16. The composition of any one of claims 1 -4, wherein the composition comprises ursodeoxycholic acid, or its salt or conjugate thereof.
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LΛI-2875394v7
17. The composition of claim 16, wherein the composition comprises ursodeoxycholic acid conjugate.
18. The composition of claim 17, wherein the ursodeoxycholic acid conjugate is tauroursodeoxycholic acid.
19. The composition of any one of claims 1 -4, wherein the composition comprises more than 1%, 5%, 10%, 25%, 50%, 75%, 90%, 95% or 99% (w/v) of a ursodeoxycholic acid and/or a tauroursodeoxycholic acid.
20. The composition of any one of claims 1-4, wherein the composition further comprises a pharmaceutically acceptable carrier.
21. The composition of any one of claims 1-4, wherein the composition, wherein the composition further comprises a neutraceutically acceptable carrier.
22. A method for producing a bile acid, comprising isolating the bile acid from a conditioned culture medium, wherein the culture medium is conditioned by hepatocytes in three-dimensional culture.
23. A method for producing a composition comprising a bile acid, comprising combining a conditioned culture medium with an appropriate carrier, wherein the culture medium is conditioned by hepatocytes in three-dimensional culture.
24. A method for producing a composition comprising a bile acid isolated from a cell culture medium conditioned by hepatocytes cultured on a living microenviromental cell tissue prepared in vitro, wherein the living microenviromental cell tissue
(a) comprises microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells, and
(b) is attached to and substantially envelopes a framework comprising a biocompatible, non-living material formed into a three-dimensional structure having interstitial spaces bridged by the microenviromental cells, wherein the hepatocytes proliferate and secrete the bile acid into the conditioned medium.
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LAI-2875394v7
25. A method for producing a composition comprising a bile acid, or its derivative, salt or conjugate thereof, comprising:
(a) inoculating hepatocytes onto a living microenviromental cell tissue prepared in vitro, wherein the living microenviromental cell tissue
(i) comprises microenviromental cells and connective tissue proteins naturally secreted by the microenviromental cells, and
(ii) is attached to and substantially envelopes a framework comprising a biocompatible, non-living material formed into a three-dimensional structure having interstitial spaces bridged by the microenviromental cells;
(b) incubating the inoculated living microenviromental cell tissue in a medium so that the inoculated cells proliferate in culture;
(c) collecting the medium; and
(d) isolating the bile acid.
26. The method of any one of claims 22-25, wherein the bile acid is a derivative of a bile acid, a salt of a bile acid or a conjugate of a bile acid, or any combination thereof.
27. The method of any one of claims 22-26, wherein the composition further comprises a pharmaceutically acceptable carrier.
28. The method of any one of claims 22-26, wherein the composition further comprises a neutraceutically acceptable carrier.
29. The method of any one of claims 24-26, wherein the microenviromental cells are fibroblasts.
30. The method of any one of claims 24-26, wherein the microenviromental cells are a combination of fibroblasts and endothelial cells, pericytes, macrophages, monocytes, leukocytes, plasma cells, mast cells or adipocytes.
31. The method of any one of claims 24-26, wherein the framework is composed of a biodegradable material.
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LAI-2875394v7
32. The method of claim 31 , wherein the biodegradable material is cotton, polyglycolic acid, cat gut sutures, cellulose, gelatin or dextran.
33. The method of any one of claims 24-26, wherein the framework is composed of a non-biodegradable material.
34. The method of claim 33, wherein the non-biodegradable material is a polyamide, polyester, polystyrene, polypropylene, polyacrylate, polyvinyl, polycarbonate, polytetrafluorethylene, or nitrocellulose compound.
35. The method of any one of claims 31-34, wherein the framework is pre-coated with collagen or other extracellular matrix.
36. The method of any one of claims 24-26, wherein the framework is a mesh.
37. The method of claim any one of claims 22-26, wherein the medium comprise an agent that increases bile acid synthesis.
38. The method of any one of claims 22-26, wherein the hepatocytes are mammalian hepatocytes.
39. The method of claim 38, wherein the mammalian hepatocytes are bear hepatocytes.
40. The method of claim any one of claims 24-26, wherein the bile acid is ursodeoxycholic acid.
41. The composition of any one of claims 24-26, wherein the composition comprises ursodeoxycholic acid conjugate.
42. The composition of claim 41 , wherein the ursodeoxycholic acid conjugate is tauroursodeoxycholic acid.
- 53 -
LΛI-2875394v7
PCT/US2009/004038 2008-07-10 2009-07-10 Compositions and methods of producing ursodeoxycholic acid WO2010005594A1 (en)

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