KR0156685B1 - Method for testing the effect of drug - Google Patents

Abstract

The present invention relates to a three-dimensional cell culture system that can be used for the culture of a variety of various cells and tissues in vitro for a long time. According to the present invention cells derived from desired tissues are seeded and grown in a pre-made matrix support matrix. The matrix support matrix consists of stromal cells, such as fibroblasts, which actively grow in a three-dimensional matrix. Stromal cells also include other cells that can be found in other soft tissues, such as endothelial cells, macrophages / monocytes, adipocytes, periphery cells, and reticular cells. The matrix matrix provides support, growth factors, and regulators for prolonged cell growth in culture. When growing in a three-dimensional matrix system, the proliferated cells mature and are properly isolated to direct the corresponding components of adult tissue as seen in vivo.

Description

[Name of invention]

How to test the effectiveness of drugs using three-dimensional culture

[Technical Field]

The present invention relates to three-dimensional cells and tissue culture system. This culture system is used for organ proliferation of cells and tissues in vitro in a very similar environment. The culture systems described herein provide for proliferation and proper cell growth to form structures similar to the tissues that are in vivo compatible.

Production cultures have a variety of applications, from transplantation or transplantation in vivo to cytotoxic and pharmaceutical compound screening in vitro and the preparation of biologically active molecules in bioreactors. The present invention relates to an embodiment described for the three-dimensional culture of bone marrow, skin, liver, muscle epithelium, pancreas, and adenocarcinoma, and also to the use of a three-dimensional culture system in blood-brain barrier model system and skin transplantation tissue, and cytotoxicity analysis. Another embodiment is described.

[Background]

Most vertebrate cell cultures grow in vitro as monolayers on artificial substrates in nutrient media. The substrate on which the monolayer grows is either a solid like plastic or a semisolid gel like collagen or agar. Disposable plastics are preferred as substrates for tissue or cell culture.

The researchers investigated the natural substrates used in relation to the basement membrane components. The basement membrane contains glycoproteins and proteoglycans that surround most cells in vivo. Collagen is used to cultivate heptosite, epithelial cells, and also endothelial tissues (Reid and Rojkund, 1979, In Methods in Enzymology, Vol. 57, Cell Culture, Jakoby Pasten, eds., New York, Acad. Press, pp. 263-278); (Vlodavsky et al., 1980, Cell 19: 607-617); (Yang et al., 1979, Proc. Natl. Acad. Sci. USA 76: 3401). Cell growth in suspended collagen (Michalopoulos and Pitot, 1975, Fed. Proc. 34: 826) and nitrate membranes (Savage and Bonney, 1978, Exp. Cell Res. 114: 307-315) were used to promote final differentiation. Do as an attempt. However, sustained cell regeneration and the culturing of tissues in these systems have not been achieved.

Fibroblast cultures of mouse embryos promote cell growth, especially at low densities. This effect is presumed to be due in part to media replenishment and substrate regulation by cell products. In such a system, the supply layer of fibroblasts grows as a confluent monolayer forming a surface suitable for adhesion of other cells. For example, it is reported that glioma grows in the confluence of normal fetal organs (Lindsay, 1979, Nature 228: 80).

Cell growth in two dimensions allows rapid cell proliferation as a convenient way to generate, observe and study cells in culture, while lacking cell-cell and cell-matrix interactions of all tissues in vivo. To study this functional and also morphological interoperability, the researchers studied the use of three-dimensional substrates such as collagen gels (Douglas et al., 1980, In Vitro 16: 306-312; Yang et al., 1979). Proc. Natl. Acad. Sci. 76: 3401; Yang et al., 1980, Proc. Natl. Acd. Sci. 77: 2088-2092; Yang et al., 1981, Cancer Res. 41: 1021-1027). Some have also announced the use of cellulose sponges alone (Leighton et al., 1951, J. Natl. Cancer Inst. 12: 545-561) or coated with collagen (Leighton et al., 1968, Cancer Res. 28: 286-296) and also the use of gel-type gelatin sponges (Sorour et al., 1975, J. Neurosurg. 43: 742-749).

Generally, this three-dimensional substrate is inoculated into cultured cells. Many types of cells penetrate the septum, proving tissue-like histology. For example, three-dimensional cholegane gels are used for culturing breast epithelium (Yand et al., 1981, Cancer Res. 41: 1021-1027) and sympathetic nerves (Ebendal, 1976, Exp. Cell Res. 98: 159-169). . In addition, various attempts have been made to regenerate tissue constructs from dispersed monolayer cultures. It has been reported that refluxed monolayers grow thicker than 10 cell thicknesses and can also develop whey tissue into multi-layered cultures under appropriate media (Kruse and Miedema, 1965, J. Cell Biol. 27: 273). (See also Schneider et al., 1963, Exp. Cell Res. 30: 449-459 and Bell et al., 1979, Proc. Natl. Acad. Sci. USA 76: 1274-1279). It has also been reported that surface keratinocytes in the human body form dematoglyphs (friction ridges) when left for several weeks without migration (Green 1978, Science 220: 1385-1388). We also report the formation of capillaries in culture of vascular epithelial cells cultured in the presence of epidermal growth factor and also in the culture of tumor cells (Folkman and Haudenschild, 1980, Nature 288: 551-556). It has also been reported that primary cultures of hepatocytes for 10-13 days in nylon mesh coated with thin collagen (Sirica et al. 1979, Proc. Natl. Acad. Sci. USA 76: 283-287; 1980, Cancer Re. 40: 3259-3267). However, long-term culture and proliferation of cells in this system did not occur.

Indeed, attempts have been made to create organ cultures of tissue such as bone marrow. The results were not satisfactory, and stromal cell layers containing different types of cells formed rapidly but were unable to maintain significant hematopoietic action (Dexter et al., In Long Term Bone Marrow Culture, 1984, Alan R. Liss, Inc.). , pp. 57-96).

Summary of the Invention

The present invention relates to a three-dimensional cell culture system that can be used to culture various cells and tissues for a long time in vitro. According to the invention, cells derived from the desired tissues are grown by inoculation into a pre-configured substrate support matrix. The substrate support matrix includes stromal cells, such as fibroblasts, which actively grow on a three-dimensional matrix. Stromal cells also include other cells from loose connective tissue, such as epithelial cells, macrophages / monocytes, adipocytes, perivascular cells, and reticular cells found in bone marrow matrix. The matrix matrix provides the support, regulators, and growth factors necessary for the long-term growth of cells in culture. When growing in this three-dimensional system, proliferating cells mature and are properly separated to form components of mature tissue similar to their counterparts found in vivo.

The present invention is based, in part, on the discovery that activation of cells in culture with stromal cell growth in three dimensions can last longer than monolayer systems. This increases the surface area of the three-dimensional matrix and consequently prolongs the proliferation period of the stromal cells. The proliferating stromal cells produce essential proteins, growth factors, and regulators that help the organ proliferation of substrates and tissue-specific cells inoculated onto the matrix matrix. In addition, the three-dimensionality of the matrix leads to spatial distribution in conditions very similar to those of living organisms, and to the formation of a microenvironment that aids cell maturation and migration. Cell growth in the presence of support is further enhanced by adding proteins, glycoproteins, glycosaminoglycans, cell septum, and other materials to the support, or by coating the support with such materials.

Using three-dimensional support, cells grow in multiple layers, resulting in the three-dimensional cell culture system of the present invention. Many cell types and tissues grow in three-dimensional culture.

In an embodiment of the invention, bone marrow, skin, liver, pancreas, muscle epithelium, adenocarcinoma, melanoma tissue, and the like are grown in a three-dimensional culture system.

The resulting culture is also used as a model system for study of physiological or pathological conditions. For example, in one embodiment of the present invention a three-dimensional culture system is used as the blood-brain gateway model system. In another embodiment, but not by way of limitation, a three-dimensional culture system of mucosal epithelium can be used as a model system to study for herpesvirus or papilloma-virus infection. The production culture can be applied in various ways, such as transplanting or transplanting cells grown in the culture into a living body, cytotoxicity screening, in vitro compound selection, and designing a bioreactor for preparing a biological material in vitro. .

3.1. Definitions and abbreviations

The following is a description of terms:

Adsorption layer: Cells that are indirectly connected by adhering to cells attached directly to a matrix or to cells directly attached to a matrix.

Stromal Cells: Fibroblasts containing or without components found in other cells and / or loose connective tissue, including epithelial cells, perivascular cells, macrophages, monocytes, plasma cells, mast cells, adipocytes, and the like.

Tissue-specific or parenchymal cells: Cells that form basic specific tissues that are distinct from support structures.

Three-dimensional matrix: (a) cells can attach (or be modified to attach cells); And (b) a three-dimensional matrix composed of a substance or / or form that allows cells to grow in more than one layer. This support is inoculated with stromal cells to form a three-dimensional matrix.

3D matrix matrix: 3D matrix inoculated with substrate cells. By confluence or semiconfluence the stromal cells begin to grow and divide according to the present invention. Substrate matrices help to inoculate later-inoculated tissue-specific cell growth to form three-dimensional cell cultures.

Three-Dimensional Cell Culture: Three-dimensional matrixes inoculated with tissue-specific cells and incubated again. In general, tissue-specific cells used when inoculating a three-dimensional matrix matrix include liver cells (or reserve cells) for these tissues, ie, new cells that will mature in the embodied cells that make up the parenchyma of the tissue. Cells should be included.

Explain the meaning of the following abbreviations:

[Brief Description of Drawings]

1 is an electron scanning micrograph showing the attachment of fibroblasts to a three-dimensional matrix and the expansion of cells across the opening of the sieve. Fibroblasts actively secrete matrix proteins and are in the appropriate subconfluence stage obtained prior to inoculation into tissue-specific cells.

2 is an electron scanning micrograph of a three-dimensional LTBMC showing 210 μm body area for the expression of red blood cells, bone marrow, and other populations. Support cells grow linearly along and surround the three-dimensional matrix.

Figure 3 is a graph showing the total cell number of the three-dimensional LTBMC adsorption and non-adsorption layer appeared for several weeks in culture. Using the medium removed every 5 days after feeding into the culture, the total cell number and cytospin product at the non-adsorption column are produced. Three-dimensional cell cultures were treated with collagen and trypsin to remove adherent cells and the number of cells in the adherence zone was measured at different intervals of LTBMC. After several weeks of culture, cell proliferation reaches a steady state.

4 is a graph showing CFU-C per 10 ⁵ cells obtained from the adsorption zone of 3D LTBMC for several weeks in culture.

5 shows a diagram of a three-dimensional skin model. Pigmented black blood cells and also endothelial / surface junctions with multiple layers of pigment-containing keratinocytes appear. The stromal cells attach to the matrix and form an endothelial component.

FIG. 6 shows electron scanning micrographs of three-dimensional substrates three days after inoculation with black blood cells. Black blood cells, which show dendrites, contain pigments and possess the ability to deliver pigments to keratinocytes, normally grow in three-dimensional systems.

7 is a micrograph showing the cross section of a three-dimensional skin media stained with hematoxylin-eosin. Normal surface (E) cell morphology and orientation are evident. The surface and endothelial (D) components completely surround the body fibers (M) and show distinct endothelial / surface junctions.

FIG. 8 is a micrograph showing epidermal regions from three-dimensional skin cultures stained with toluidine. Keratinocytes (K) form normal morphology and also contain pigment (P) particles. The stratum corneum (SC) is evidence of cellular maturation.

Figure 9 is a micrograph of a three-dimensional skin model implanted in rats 7 days after transplantation. Distinct endothelial and surface junctions are shown. Cells show anchorage points attached to the mesh without rejection.

FIG. 10 is a micrograph of a three-dimensional skin model implanted in a mouse 7 days after transplantation. Collagen genus (c) and all cell types, especially cells containing keratinocytes (k), fibroblasts (f), adipocytes (a) and soft muscle cells (s), arranged in a natural configuration surrounding nylon mesh fibers (m) Appears to be.

FIG. 11 is a micrograph of mature liver culture grown according to the three-dimensional culture method of forming a three-dimensional multilayered tissue on liver matrix cells.

FIG. 12 is a micrograph showing that during 10-20 days post-immune hepatocytes actively divide into a three-dimensional culture similar to hepatoblasts or cells of regenerated liver.

Figure 13 is a micrograph showing the cross-section of three-dimensional tissue culture of muscle epithelium.

Figure 14 is a micrograph showing the cross section of three-dimensional tissue culture of the pancreas. Arrows indicate enzyme source particles in acimar cells. Asterisks are stromal cells.

FIG. 15 is a micrograph showing a cross section of a three-dimensional tissue culture model system of the cerebral blood barrier. Dark arrows point to small vascular epithelial cells and white arrows point to nerve cells. Asterisks indicate astrocytes.

Figure 16 is a micrograph showing a cross section of three-dimensional tissue culture of adenocarcinoma.

Figure 17 shows a graph comparing the response of fibroblasts grown in a monolayer with a matrix to full-thick bone marrow grown in the three-dimensional mesh system of the present invention. Substrates show a dose-related response to dadriamycin by neutral-red analysis of cell viability.

Figure 18 shows a graph showing the results of a neutral-red assay showing dose-related responses to cis-platinum by substrate and bone marrow three-dimensional culture.

19 is a photograph showing the surface state of the complete thickness wound to the small pigs 10 days after human body skin transplantation. Minimal shrinkage was observed without rejection or dehydration.

FIG. 20 is a micrograph showing the histological evaluation of the budding dermis showing the cross section of mesh fibers with active fibroblasts and naturally-secreted collagen.

FIG. 21 is a micrograph comparing wounds treated with budding skin (left) and microbial degradation mesh (right), respectively. Examine the shrinkage, pigmentation, and hair growth of wounds with budding buds.

22 is a micrograph showing the histological evaluation of the biopsy removed from the site treated with mesh absorbed by human skin fibroblast lysate. The epithelial cell growth around each mesh fiber is examined.

FIG. 23 is a micrograph showing the histological evaluation of skin measurements 21 days after implantation. If epithelial cells are transferred to the dermis and adhered evenly, normal differentiation and growth can be seen. Late peg growth is a hallmark of transplanted skin. Rate peg degradation can be observed within three to four months.

FIG. 24 is a micrograph showing the upper body of full-tightness 21 days after treatment with budding skin.

FIG. 25 is a micrograph showing the histological evaluation of the epidermal / dermal region depicted in N of FIG. Examine keratinocyte adhesion and even growth on dermis measurement. The mesh fibers appear up to 21 days after transplantation and the fibroblasts surrounded by naturally secreted collagen fibers remain active.

Detailed description of the invention

3D culture system

The present invention relates to a three-dimensional partition wall and also to the use of this as a structure for a three-dimensional multilayer cell culture system. In conventional, known tissue culture systems, cells grow in a single layer. Cells grown in the three-dimensional substrate support according to the present invention grow in multiple layers to form a cell matrix. This matrix system is closer to physiological conditions than the aforementioned monolayer tissue culture system in vivo. The three-dimensional cell culture system is applicable to the proliferation of various cell types and the formation of multiple tissues including bone marrow, skin, liver, pancreas, kidney, adrenal gland and nerve tissue.

Various applications of the culture system. For example, in tissues such as skin and organs, the three-dimensional culture is implanted or transplanted into a living organ as it is. Alternatively, for diffuse tissue such as bone marrow, proliferating cells can be isolated from the culture system for transplantation. Three-dimensional cultures can also be used for in vitro cytotoxicity testing and compound selection. In another application, three-dimensional culture systems can be used as bioreactors to produce large quantities of cell products.

In the present invention, cells derived from desired tissues (tissue-specific cells or parenchymal cells) are inoculated on a preconfigured three-dimensional matrix matrix and cultured. The matrix matrix contains stromal cells grown in a three-dimensional matrix or tissue. Stromal cells include fibroblasts with or without another cell described herein and / or components. Fibroblasts and other cells and / or components include substrates that originate in fetal or adult origin or come from good sources such as skin, liver, pancreas, and the like. Such tissues and / or organs may be obtained according to appropriate biopsy or autopsy. Indeed, it provides abundant stromal cells and components from the cadaveric organs.

Fetal fibroblasts help the growth of a variety of cells and tissues in a three-dimensional culture system, thus inoculating the matrix to form a general substrate support matrix for culturing a variety of cells and tissues. In some cases, however, it is desirable to use specificity rather than the usual matrix support matrix, resulting in the acquisition of stromal cells and components from particular tissues, organs or individuals. For example, when in vivo transplantation or in vivo transplantation by three-dimensional culture, it is desirable to obtain stromal cells and components from the graft or the individual to receive the endograft. This approach is particularly advantageous where there is likely to be an immunological rejection of the graft and / or graft against host disease. Furthermore, fibroblasts and other stromal cells also and / or components are induced in homologous tissue to be cultured in a three-dimensional culture system. This is beneficial for culturing tissues, where specialized stromal cells have a specific structural / functional role, for example, glial cells of neurological tissues, Kupffer cells of liver, and the like.

When inoculated on a three-dimensional matrix, stromal cells proliferate in the matrix and aid in tissue-specific cell growth inoculated into the three-dimensional culture of the present invention. Indeed, when inoculated with tissue-specific cells, the three-dimensional matrix support matrix actively propagates the culture for a long time. Growth and regulators may be added to the culture but are not necessary because they are assimilated by the substrate support matrix.

In the present invention, since it is important to recreate the microscopic environment found in specific tissues in vivo during the culture, the extent of the growth of the substrate prior to inoculation of the parenchymal cells depends on the type of tissue grown in the three-dimensional tissue culture. For example, in a three-dimensional culture of bone marrow, it is preferable to inoculate hematopoietic cells into a semi-conjugated matrix matrix. However, in the three-dimensional tissue culture of the skin according to the present invention, it is preferable that the stromal cells join before inoculation with keratinocytes and / or pigment cells to recreate the endothelial component structure of the skin. Importantly, the stromal cells in culture exit through the pores of the mesh, confluent matrix cells show no contact inhibition and the stromal cells continue to grow, isolate, and remain functionally active.

The present invention is based, in part, on the discovery that three-dimensional stromal cell growth can continue to proliferate actively in matrix and also tissue-specific cells for longer periods of time than monolayers. Moreover, the three-dimensional system assists in the maturation, differentiation and isolation of in vitro cultured cells, resulting in components of mature tissue similar to the counterparts found in vivo.

Although the Applicant has no obligation or responsibility to explain the mechanism of the practice of the invention, a number of factors adhered to the three-dimensional culture system contribute to the successful outcome:

(a) Three-dimensional matrices increase the surface area to which proteins adhere and consequently the stromal cells will adhere to.

(b) Because of the three-dimensionality of the matrix, stromal cells continue to grow actively, which contrasts with cells in monolayer cultures that gradually merge and exhibit contact inhibition, where growth and division are stopped. Growth and regulatory factors following stromal cell replication stimulate, regulate and differentiate the proliferation of cells in culture.

(c) Three-dimensional matrices allow spatial distribution of cellular components more similar to those found in the corresponding tissues of living organisms.

(d) Increasing the potential volume for cell growth in the three-dimensional system contributes to constructing localized microenvironments that contribute to cellular maturation.

(e) Three-dimensional bulkheads offer the possibility of expanding the movement of mobile cells, such as macrophages, monocytes, and lymphocytes in the adhesion layer, maximizing cell-cell interactions.

(f) It was recognized that not only growth / differentiation factors but also appropriate cell interactions are required to sustain differentiated cell phenotypes. The present invention effectively recreates the tissue microenvironment.

Three-dimensional substrate support, culture systems and their maintenance, and the various uses of three-dimensional cultures are described in detail in the following subsections.

5.1. Composition of 3D Substrate Matrix

The three-dimensional support is in (a) a cell to which it can be grafted (or deformable for cell grafting), and (b) also in a substance or / or form that allows the cell to grow in more than one layer. Nylon (polyamide), Taken (polyester), Polystyrene, Polypropylene, Polyacrylate, Polyvinyl compound (i.e. polyvinyl chloride), Polycarbonate (PVC), Polytetrafluoroethylene (PFE; Teflon), Ter The matrix is made from a variety of materials, including mannox (TPX), nitrocellulose, cotton, polyglycolic acid (PGA), cat gut sutures, cellulose, gelatin, and textran. These materials are then woven into a mesh to form a three dimensional matrix. Materials such as nylon and polystyrene are not suitable for cell grafts. When used as a three-dimensional support matrix, the matrix is pre-treated prior to stromal inoculation to improve stromal cell grafting to the matrix. For example, the nylon septum is treated with 0.1 M acetic acid before inoculation with stromal cells and then cultured in polylysine, FBS, and / or collagen to coat the nylon. Polystyrene is similarly treated with sulfuric acid.

When the three-dimensional culture is directly implanted into a living body, it is preferable to use a biodegradable matrix such as polyglycolic acid, cat visceral suture or gelatin. If the culture is to be preserved for a long time or stored cold, it is preferable to use non-degradable materials such as nylon, teqron, polystyrene, polyacrylate, polyvinyl, teflon, cotton and the like. A convenient nylon mesh for use in the present invention includes Nitex, a nylon filter mesh having an average pore size of 210 µm and a nylon fiber diameter of 90 µm (# 3-210 / 36 Tetko, Inc., N.Y.).

Stromal cells of fibroblasts with or without the cells described below are seeded into the matrix. These fibroblasts are derived from organs such as skin, liver, and pancreas that can be obtained by biopsy (adequate) or by necropsy. Indeed, fibroblasts can be obtained in large quantities in organs of appropriate carcasses. As described above, fetal fibroblasts can be used to form a common three-dimensional matrix of matrix that aids in the growth of various cells and / or tissues. However, specific substrate matrices can be prepared by inoculating a three-dimensional matrix with cultured allogeneic tissues or with fibroblasts derived from individuals who will subsequently receive cells or tissues grown in culture according to the three-dimensional system of the present invention. .

Fibroblasts are easily isolated by degrading the appropriate organ or tissue that has been supplied as a source. This is easily accomplished using methods known to the skilled person. For example, tissues or organs are treated or mechanically degraded with chelating agents or degrading enzymes that can weaken the binding forces between neighboring cells and disperse the tissue into cell suspensions without cell destruction. Enzymatic degradation can be achieved by breaking down the tissue and treating the broken tissues alone or in combination with other enzymes. Such enzymes include, but are not limited to, trypsin, chymotrypsin, collagen, elastase, and / or hyaluronidase, DN enzyme, pronase, dispase and the like. Mechanical disturbances are also possible in a number of ways, including grinders, blenders, sieves, shredders, pressure cells or insulators. (For tissue digestion methods, Freshney, Culture dof Animal Cells.A Manual of Basic Technique, 2d Ed. , AR Liss, Inc., New York, 1987, Ch. 9, pp. 107-126).

When tissue is broken down into individual cell suspensions, these suspensions can be classified into subpopulations to obtain fibroblasts and / or other stromal cells and / or components. This also includes cloning and also screening for specific cell types, selective destruction of unwanted cells (negative selection), separation based on split cell adhesion of mixed populations, freeze-thawing, fractional adhesion of mixed population cells, filtration, conventional This can be achieved by standard methods for cell separation, including regional centrifugation, centrifugal elutriation (reflux centrifugation), unit gravity separation, countercurrent distribution, electrophoresis, and fluorescence-active cell separation. See Freshney, Culture of Animal Cells for sex screening and cell separation methods (A Manual of Basic Techniques, 2d Ed., AR Liss, Inc., New York, 1987, Ch. 11 and 12, pp. 137-168). ).

For example, fibroblast separation is performed as follows: fresh tissue specimens are washed thoroughly and ground in Hanks' equilibrium salt solution (HBSS) to remove serum. Crushed tissue is incubated for 1 hour to 12 hours in a digestive enzyme solution such as trypsin. The isolated cells are then suspended, pelleted by centrifugation, and placed in a culture dish. Fibroblasts adsorb before other cells to selectively separate and regrow the appropriate amount of stromal cells. Isolated fibroblasts grow, join, remove from confluent cultures and inoculate on a three-dimensional matrix (Naughton et al., 1987, J. Med. 18 (34): 219-250). Inoculation of high concentration stromal cells, ie, cells of about 10 ⁶ to 5 × 10 ⁷ cells / ml, into the three-dimensional matrix constitutes a three-dimensional substrate support in a short time.

In addition to fibroblasts, other cells are added to form the three-dimensional matrix matrix necessary to aid long-term growth in culture. For example, other cells found in loose connective tissue are inoculated with the fibroblasts on the three-dimensional substrate support. Such cells include epithelial cells, perivascular cells, macrophages, monocytes, plasma cells, mast cells, adipocytes and the like. These stromal cells can be easily induced in appropriate organs such as skin and liver according to the known methods discussed above. In one embodiment of the present invention, stromal cells specific for the particular tissue to be cultured are added to the fibroblast matrix. For example, stromal cells of hematopoietic tissues include fibroblasts, epithelial cells, macrophage / monocytes, adipocytes, reticular cells and the like, which are used to form three-dimensional semiconfluent substrates for long-term culture of bone marrow in vitro. Hematopoietic matrix cells are readily obtained from 'buffy coatings' formed in bone marrow suspensions by low speed centrifugation at 3,000 × g. Stromal cells of the liver include fibroblasts, Cooper cells, blood vessels and biliary epithelial cells. Similarly, it is used as a glial substrate to assist in the proliferation of neurological cells and tissues; Glial cells for this purpose can be obtained following trypsinization or collagen digestion of immature or mature brains (Ponten and Westermark, 1980, in Federof, S. Hertz, L., eds. Advances in Cellular Neurobiology, Vol. 1, New York, Academic Press pp. 209-227).

Again, when using cultured cells for biotransplantation or internal transplantation, it is desirable to obtain stromal cells from the tissue of the patient. Proteins (e.g. collagen, elastic fibers, reticular fibers), glycoproteins, glycosaminoglycans (i.e. heparan sulfate, chondroitin-4-sulfate, chondroitin-6-sulfate, sulfuric acid) in the matrix in the presence of a three-dimensional substrate support matrix Dermatan, keratin sulfate, etc.) support matrix or other substances are added to the matrix or coated with the matrix support to improve cell growth.

After inoculation of the stromal cells, the three-dimensional matrix is incubated in an appropriate nutrient medium. Commercially available media such as PRMI 1640, Fisher's Iscove's, McCoy's, etc. are suitable. It is important to maximize the proliferative activity of the three-dimensional matrix matrix suspended or suspended in the incubator during the incubation period. In addition, the culture is injected periodically to remove spent media, reduce released cells, and add fresh media again.

In culture, the stromal cells grow linearly along the three-dimensional matrix and cover them and grow toward the pores of the matrix. Prior to inoculation of the matrix matrix with tissue-specific cells, it is important to grow the cells to a certain degree that reflects the amount of stromal cells present in the living tissue.

The holes in the septum are of an appropriate size, allowing stromal cells to grow across them. Maintaining active growth of the stromal cells that extend across the septum enhances the production of growth factors assimilated by the stromal cells, thereby assisting organ cultures. For example, if the hole is too small, the stromal cells will merge quickly and will not easily exit the mesh; The collected cells show contact inhibition and also stop the production of the appropriate factors necessary to maintain organ culture while aiding proliferation. If the pores are too large, the stromal cells cannot stretch across the pores; It also reduces stromal cell production of appropriate factors necessary to maintain organ culture while aiding proliferation. When using meshed matrices, it has been found that hole sizes in the range of about 150 μm to 220 μm are satisfactory to carry out as practiced here. However, other sizes may be used, depending on the complexity of the three-dimensional structure and the matrix. Indeed, any form can be used in accordance with the present invention as long as the stromal cells are capable of expanding, continuously replicating and growing for a long time.

Different kinds of collagen of various kinds attached to the matrix can affect the subsequent inoculation of tissue-specific cell growth. For example, for ideal growth of hematopoietic cells, the matrix preferably comprises collagen types (III), (IV) and (I) in an approximately 6: 3: 1 ratio in the initial matrix. In three-dimensional skin culture systems, collagen type (I) and (III) are preferably deposited on the initial matrix. The proportion of collagen species deposited can be controlled or enhanced by selecting fibroblasts that produce the appropriate type of collagen. Complement can be activated and can be achieved using appropriate heterologous or subclass monoclonal antibodies that define specific collagen types. This antibody and supplement are used to reversely select fibroblasts that express the desired collagen type. Alternatively, the substrate used to inoculate the matrix may be a cell mixture that synthesizes the appropriate collagen form. The distribution and origin of the five collagen types are shown in Table 1.

Therefore, appropriate stromal cells can be selected according to the tissue to be cultured and the desired collagen type to inoculate the three-dimensional partition wall.

During the culture of the three-dimensional substrate support, proliferating cells are released from the matrix. The release cells adsorb to the vessel walls of the culture and continue to proliferate to form a confluent monolayer. For example, this phenomenon should be minimized or prevented by removing the releasing cells or moving the three-dimensional matrix matrix to new blood vessels during the feeding process. The presence of a confluent monolayer in the tube stops cell growth in a three-dimensional matrix or culture. The confluent monolayer is removed or the matrix is transferred to fresh medium in a new tube to preserve the proliferative activity of the three-dimensional culture system. This should only be done in culture tubes where the confluence of the substrate monolayer exceeds 25%. Alternatively, it is also possible to stir the culture system to prevent release cells from adhering or to fix the culture system and to continue injecting fresh medium through this system instead of periodically supplying the culture. The inflow rate maximizes the proliferation in the three-dimensional culture and is adjusted to a value that can be removed by washing the cells released from the matrix, which in turn prevents the cells from adhering to the wall of the tube and gradually joining. In preparation for future use, the stromal cells may be harvested and stored cold.

5.2. Tissue-specific Cell Inoculation and Culture Preservation in Three-Dimensional Matrix

When the three-dimensional matrix is properly grown, tissue-specific cells (reticular cells) for culturing are seeded on the matrix. The cells of the inoculum are preferably higher concentrations than low concentrations and the growth in culture increases much more rapidly. The cells to be selected for inoculation vary depending on the tissue to be cultured, including bone marrow, skin, liver, pancreas, kidneys, nervous system tissue, and also the adrenal gland.

For example, but not by way of limitation, various epithelial cells may be cultured in a three-dimensional biological substrate support. Such epithelial cells include oral mucosa and gastrointestinal (G.I.) vascular cells. Such epithelial cells can be isolated by enzymatic treatment of tissues according to known methods and then expanded in culture and the epithelial cells are applied to a three-dimensional stromal support cell matrix (neo-mucosa). If submucosal tissue is present, oral mucosal cells and G.I. It supplies growth factors and other proteins that will promote normal division and degradation of cells inside the tube. This method can also be used to successfully grow other epithelial cells, including nasal epithelium, respiratory tract epithelium, vaginal epithelium, and corneal epithelium.

Various types of tumors are grown on three-dimensional living substrate support. Examples of such tumors include adenocarcinoma and malignant melanoma, which are caused in situ or metastatic. Such cultures are constructed in a manner similar to other three-dimensional epithelial cultures. In summary, stromal cells from a patient's tumor or normal tissue or an allogeneic source are constructed on the mesh. After nearly reaching confluence, stromal cells are inoculated with tumor cells. Tumor cells continue to divide rapidly and form three-dimensional solid tumors. Tumor cells grown in three-dimensional support exhibit and resemble the bioenvironment-like morphology and also escape the antigen surface in a manner similar to that in solid tumors; Malignant cells grown in a monolayer do not exhibit the same similarity as tumor tissue in vivo. The physiological growth of tumor cells can be applied to the research and development of new chemotherapeutic agents, individual chemotherapeutic regimens and transfer mechanisms. In addition, these tumor cultures can be used for individual immunotherapy. In the practice of CR release studies, Lak cells produce a much greater response to tumor cells grown in three dimensions compared to cells cultured in a single layer. Traditional techniques are used to take immune cells from patients and give them sensitivity to their own tumor cells grown in three-dimensional culture.

Typically, this inoculum contains stem cells (also called reserve cells) for this tissue; These cells mature into specialized cells that form various tissue components.

Parenchymal or tissue-specific cells used in the inoculum are obtained from cell suspensions prepared by isolating the desired tissue using the standard methods described for obtaining stromal cells in section 5.1. The whole cell suspension is used to inoculate the 3D substrate support matrix. As a result, while regenerative cells in homogenized material properly differentiate on proliferation, maturation and septum on the matrix, non-regenerative cells do not. Specific cell types can be isolated from the appropriate fragments of cell suspensions according to the standard methods described in Section 5.1 for known cell sorting. If liver or preliminary cells are easily isolated, these cells can be used to preferentially inoculate the three-dimensional substrate support. For example, in bone marrow cultures, three-dimensional substrates can be inoculated with fresh or cold preserved bone marrow cells. In skin culture, three-dimensional substrates are inoculated with pigment cells and keratinocytes. In liver culture, three-dimensional substrates are inoculated with pancreatic endocrine gland cells. A method for obtaining reticular cells from various tissues was studied (Freshney, Culture of Animal Cells) (A Manual of Basic Technique, 2d Ed., AR Liss, Inc., New York, 1987, Ch. 20, pp 257-288 ).

During the culturing process, the three-dimensional cell culture system is suspended or suspended in nutrient medium. The cultures are fed periodically with fresh culture. Care must be taken to ensure that cells released from the culture do not adhere to the wall of the tube where they multiply and form a confluent monolayer. Cell release in three-dimensional cultures occurs more readily when culturing diffuse tissues relative to constructed tissues. For example, the three-dimensional skin culture of the present invention is histologically and morphologically typical; The different inner and outer layers do not release the cells to the surrounding medium. In contrast, the three-dimensional bone marrow cultures of the present invention release into the medium in a manner similar to the release of mature non-adherent cells into the bone marrow of the living body. As described above, the released cells adhere to the culture tube to form a confluent monolayer, and the proliferation of the three-dimensional culture is stopped. Remove the released cells during feeding, transfer the three-dimensional culture to a new tube, stir the culture, refeed nutrients from the culture and remove the released cells to prevent the cells released on the tube wall from adsorbing This problem can be avoided by continuously feeding fresh medium at a rate sufficient to be below. In preparation for future use, the released cells can be collected and stored cold.

Growth and regulators do not need to be added because they are made by three-dimensional stromal cells. However, adding these factors or inoculating other specialized cells enhances, changes or modulates proliferation and cell maturation in culture. The growth and activity of the cells in culture were determined by insulin, growth hormone, somatomedin, colony stimulating factor, erythropoietin, envelope growth factor, hepatocellular hematopoietic factor (hepatopoietin), and liver cell growth factor. Influenced by growth factors. Other factors for regulating proliferation or differentiation include prostaglandins, interleukins, naturally occurring calons and the like.

5.3. Use of 3D culture system

The three-dimensional culture system of the present invention can be variously applied. Transplanting or transplanting the cultured cells or the matrix itself from the matrix into a living body; In vitro selection of cytotoxic compounds, allergens, growth / regulators, pharmaceutical compounds, etc .; Interpretation of disease mechanisms; Study of the mechanism by which drugs or growth factors act; Diagnosing and observing the cancer of the patient; Gene therapy; It also includes the preparation of biologically active substances.

In biotransplantation or endogenous transplantation, cells or three-dimensional cultures obtained from the culture can be internally transplanted according to relevant tissue types. For example, three-dimensional bone marrow cultures can be preserved in vitro for long periods of time; Cells isolated from the culture are used for transplantation or the entire culture is internally transplanted. In contrast, in the case of skin culture, the three-dimensional culture itself may be implanted into a living body to treat burns, skin ulcers, wounds, and the like.

In the present invention, three-dimensional tissue culture endografts are used to replace or augment discharge tissue, insert new or deformed tissue, change into artificial organs, or combine with biological tissue or constructs. For example, but not by way of limitation, in a particular embodiment of the present invention (iii) a three-dimensional bone marrow culture graft used to replace bone marrow destroyed during chemotherapy; (Ii) three-dimensional liver tissue grafts used to enhance liver function in patients with cirrhosis; And (iii) genetically modified cells grown in a three-dimensional culture (such as a three-dimensional culture of fibroblasts expressing a recombinant gene encoding insulin); (Iii) hip artificial organs coated with three-dimensional culture or cartilage; In addition, (i) artificial tooth organs and the like which are bonded to the three-dimensional culture of the oral mucosa.

Three-dimensional cultures select a wide variety of compounds, such as cytotoxic compounds, growth / regulatory factors, pharmaceutical agents, etc. in vitro. When this is done, the culture is retained in vitro and exposed to the test compound. The activity of a cytotoxic compound is measured according to its ability to damage or kill cells in culture. This can easily be evaluated by biostaining. Efficacy of growth / regulatory factors can be assessed by analyzing the cell content of the matrix, ie total cell number and discriminator cell number. This can be accomplished by standard cytological or histological methods, including immunocytochemistry, in which an antibody is used to determine form-specific cell antigens. The efficacy of various drugs in normal cells cultured in a three-dimensional system is evaluated. For example, drugs that enhance red blood cell formation can be tested in three-dimensional bone marrow cultures. Drugs that are effective in cholesterol metabolism, ie, lower cholesterol formation, can be tested in a three-dimensional interculture. Three-dimensional culture of tumor-cells is used as a model system for, for example, anticancer efficacy test.

The three-dimensional culture of the present invention can be used as a model system for the study of physiological or pathological conditions. For example, in certain embodiments of the invention a three-dimensional culture system is used as a model of blood-brain barrier; This model system is used to study the penetration of matter through the blood-brain barrier. In another embodiment, a three-dimensional culture system of mucosal epithelium is used as a model system for the study of herpesvirus or papillomavirus infection; This model system can be used for anti-barrier drug testing.

In addition, with the help of three-dimensional cell cultures can diagnose and treat malignancies and diseases. For example, biopsies of tissues (ie bone marrow, skin, liver, etc.) are taken from malignant patients. When biopsy cells are cultured in the three-dimensional system of the present invention, the malignant cells are cloned during the growth of the culture. As a result, the chance of detection of malignant substances is increased, thus increasing the accuracy of diagnosis. This is particularly useful for diseases such as AIDS that bleed in vivo in infected populations of cells. Moreover, the patient's culture is used to screen for cytotoxic or pharmaceutical compounds in vitro to identify compounds that are most effective, ie killing malignant or diseased cells, while normal cells have the capacity to preserve well. . This agent is used again in the patient and treated therapeutically.

In the present invention, a relatively small amount of bone marrow is obtained from a diseased patient and destroyed by chemotherapy or radiation. Again, the appropriate chemotherapeutic agent is used to remove the diseased cells from the bone marrow specimens, expand the sample in vitro, and administer to the patient again. A three-dimensional culture system can be utilized for larger volumes of purified bone marrow, with treatment of diseased small volumes of bone marrow to be more effectively removed and then expanded in vitro. The side effects of most purifying agents are the destruction and division of normal hematopoietic skin cells, which take longer to transplant and increase mortality from secondary infections. One effective purifying agent for severe non- lymphocytic leukemia is 4-hydroxyperoxyiolo phosphamide (4HC), which inevitably leads to the death of malignant cells. In conventional treatment, diseased 50 ml to 1,000 ml of bone marrow is treated by culturing the bone marrow at 60-100 ng 4HC / ml ex vivo. The bone marrow is then cryopreserved and re-administered to patients 2-3 weeks after clinical chemotherapy treatment. In the present invention, a comparative amount of bone marrow is taken, purified with 4HC and expanded in three-dimensional culture in vitro, which allows for faster transplantation and reduces patient mortality.

In vitro methods are useful for reducing the rejection of cells required for transplantation to both animals (marrow bone marrow transplants) and humans (heterogeneous epithelial transplants). Three-dimensional bone marrow cultures can also promote cell resistance to external antigens. At this point, the donor's hematopoietic cells grow in the recipient's three-dimensional stromal cells. These cultures grow in the presence of a three-dimensional thymic culture that supplies additional growth and differentiation factors that will induce the growth of lymph in the bone marrow system. When hematopoietic cells are cloned and matured, they are positive to give their own recipient cell antigens, and as a result, resistance to cells outside of them is developed.

Depending on the use of proliferated cells and tissues, various specialized cells can be added to the three-dimensional culture. For example, long-term proliferation of bone marrow cells can be enhanced by adding mononuclear cell populations to cultures in three-dimensional cultures, adding growth factors to culture media, or by using controlled stromal cells to produce the desired growth factor (s). Can be. Cells collected in these cultures are implanted and banked with angioplasty. Adding lymphocytes taken from the patient to three-dimensional skin cultures can help to assess and diagnose immunological diseases such as autoimmune diseases. Similarly, adding lymphocytes and mast cells taken from a patient to a three-dimensional skin culture can assess allergic reactions to various allergens without exposing the patient to allergens. The lymphocytes and mast cells of the patient are then exposed to various allergens. When the patient is bridged with sensitive allergens, binding of lymphocyte-producing IgE to surrounding mast cells releases a vasoactive modulator such as histamine. It may be determined that in response to an allergen exposed to a three-dimensional culture, such modulators exhibit allergic reactions in patients. This allows for allergy testing without exposing the subject to dangerous and potentially harmful allergens. This system is similarly used for testing cosmetics in vitro.

Also provided are excipients for injecting genes and gene products in vivo for use in gene therapy in the three-dimensional culture system of the present invention. For example, the prepared DNA method can be used to include genes deficient in a patient under the control of viral tissue—especially promoters. Recombinant DNA constructs containing genes can be used to transform or transfect host cells that are first cloned and then cloned into a three-dimensional culture. Three-dimensional cultures expressing the active gene product can be internally transplanted into individuals lacking the gene product.

There are several advantages to using a three-dimensional culture system for gene therapy. First, because the culture contains eukaryotic cells, the gene product is properly expressed and processed in the culture to form an active substance. Second, gene therapy is only useful when a large number of transfected cells have increased in clinical value, search value and utility; According to the three-dimensional culture of the present invention, a plurality of transfected cells can be expanded and amplified (via cell division).

Expression control components allow for regulated expression of genes and the resulting product is only synthesized when required in vivo. The choice of promoter depends on the type of tissue and cell cultured. Preferred are tissues and cells capable of secreting proteins (ie, characterized by abundant endoplasmic reticulum and Golgi complex). Liver and other granular tissues can be selected for this purpose. When using hepatocytes, hepatic specific viral promoters, such as the Hepatitis B virus component, can be used to inject foreign genes into the hepatocytes and also regulate the expression of these genes. These cells are then cultured in the three-dimensional system of the present invention. Alternatively, liver-specific promoters such as albumin promoters can be used.

Transcriptional regulatory parts having tissue specificity as described above include, but are not limited to: Elasta I gene regulatory region active in pancreatic aquinar cells (Swift et al., 1984, Cell 38: 639-646; Ornitz et al., 1986, Cold Spring Harbor Symp. Quant. Biol. 50: 399- 409 MacDonald, 1987, Hepatology 7: 42s-51s); Insulin gene regulatory region active in pancreatic beta cells (Hanahan, 1985, Nature 315: 115-122); Immunoglobulin gene regulatory region active in lymphocytes (Grosschedl et al., 1984, Cell 38: 647-658; Adams et al., 1985, Nature 318: 533-538; Alexander et al., 1987, Mol. Cell Biol. 7: 1436-1444); Active albumin gene regulatory region in the liver (Pinkert et al., 1987, Genes and Devel. 1: 268-276); Alpha-fetoprotein gene regulatory region active in the liver (Krumlauf et al., 1985, Mol. Cell. Biol. 5: 1639-1648; Hammer et al., 1987, Science 235: 53-58); Alpha-1-antitrypsin gene regulatory region active in the liver (Kelsey et al., 1987, Genes and Devel. 1: 161-171); Beta-globin gene regulatory region active in myeloid cells (Magram et al., 1985, Nature 315: 338-340; Kollias et al., 1986, Cell 46: 89-94); Myelin protein gene regulatory regions active in oligodendrosite cells in the brain (Readhead et al., 1987, Cell 48: 703-712); Myosin light chain-2 gene regulatory region active in bone muscle (Shani, 1985, Nature 314: 283-286); Gonadotropin releasing hormone gene regulatory regions active in the hypothalamus (Mason et al., 1986, Science 334: 1372-1378) and the like.

In another embodiment of the invention, three-dimensional cultures are used to facilitate gene transduction. For example, a three-dimensional culture of fibroblasts containing a recombinant viral expression vector can deliver the recombinant virus into cells in contact with the matrix matrix, and as a result, mimic the viral gene in vivo. Three-dimensional culture systems are a way to achieve more efficient gene transduction than current DNA transfection methods.

In another embodiment of the present invention, a three-dimensional culture system is used in vitro to produce high yield biological products. For example, cells that naturally produce large quantities of particular biological products (ie, growth factors, regulators, peptide hormones, antibodies) or host cells that form genetically engineered exogenous products may be cultured in vitro in three dimensions. The system can be used to expand clonally. Once the transformed cells secrete the gene product into the nutrient medium, the product can be separated from the medium using standard separation methods (ie, HPLC, column, chromatography, electrophoresis, etc.). Bioreactors can be designed in a form that favors continuous infusion methods to supply three-dimensional cultures in vitro. Basically, when fresh medium is passed through a three-dimensional culture, the gene product is washed in the culture along with the cells released during the culture. Gene products may be separated from the media effluent used (ie by HPLC column chromatography, electrophoresis, etc.).

In the following subsections various embodiments of the invention are described. This is for illustrative purposes only and is not limiting. The three-dimensional culture system of the present invention will be described based on the types of cells and tissues used in various systems. This description includes, but is not limited to, especially bone marrow, skin, liver, and pancreas. On the other hand, it is understood that the three-dimensional culture system can be applied to other kinds of cells and tissues. The invention also shows by way of example the characteristic data obtained in each system described.

6. 3D bone marrow culture system

Provided is a three-dimensional culture system of the present invention for bone marrow cell replication in a test comparable to physiological conditions. Importantly, the bone marrow cells replicated in this system include all cells present in normal bone marrow, and it is presumed that all these kinds of cells are in the original bone marrow inoculation source to initiate culture.

Bone marrow cells in culture alone are limited, but long-term growth of cultures is possible if stromal cells or their secretion products are contained (Long-Term Bone Marrow Culture, DG Wright JS Greenberger, eds., AR Liss). , New York, (1984), pp. 141-156).

In the present invention, a bone marrow cell is a mixture of stromal cells including fibroblasts (fetal or bone marrow) or cells containing stromal components of normal bone marrow, including fibroblasts, macrophages, reticular cells, adipocytes, and the like. Grow in three-dimensional aids in co-cultures together. Factors from the media or stromal cell subsets of spleen or hepatic macrophage cultures may be added to the culture. The three-dimensional culture system of the present invention is a multi-potent hematopoietic lineage cell that has the ability to reassemble the bone marrow when the bone marrow is destroyed by an intrinsic or environmental disease or by treating such a disease with chemotherapy or / or radiation. It is shown that the proliferation can be maximized.

Using conventional monolayer cell cultures, stem cells with bone marrow reactivation activity (MRA) have been shown to continually replicate long-term bone marrow cultures in mice. However, in this system, mature hematopoietic cell expression is mainly limited to the bone marrow system and the mononuclear cell line. Monolayer cultures of bone marrow cells from liver and non-human primates show a constant decrease over time in analytical progeny (CFU-GM, CFU-GEMM, GFU-E, etc.). The mouse mature cells expressed in this monolayer culture of mice are granulocytes. In contrast, hematopoietic hematoma and hematopoietic progenitors of all blood cell lines appear to replicate and proliferate in the three-dimensional matrix culture system of the present invention. Moreover, differentiation occurs in a physiological way. For example, red blood cells, bone marrow cells, lymphocytes, macrophages, megakaryocyte colonies occur in the same culture using the system of the present invention as described. Sustained proliferation of the identified species can predict the lineage of this system.

6.1. Obtaining Bone Marrow Cells

Bone marrow cells used as inoculum are obtained directly from the donor or obtained from cold storage stocks. The cells are first separated from the reticular cells by physical means. Thus, a small amount (10-15 cc of bone marrow per peripheral blood suspension) is aspirated through the iliac crest of the donor. For transplant purposes, (a) each individual is 40 years of age or younger when taking bone marrow for culture or cold preservation, and (b) the most ideal result is obtained when the subject is disease free: It does not limit these criteria. Methods of aspirating a donor's bone marrow are also known. Examples of bone marrow aspirate devices and methods are shown in US Pat. Nos. 4,481,946 and 4,486,188.

When culturing bone marrow to treat patients with metastatic disease or blood related incurable disease, malignant cells must be removed by physical or chemotherapy prior to culturing the patient's bone marrow. Currently, significant samples are required because physical and chemotherapy ablation indiscriminately kills malignant and normal cells. However, alternative methods for malignant cell removal have also been developed recently. For example, antibodies with specificity to malignant cells are tested to target toxic agents or specifically to kill malignant cells. This selective removal method is effective when the sample size is small. The three-dimensional culture system of the present invention can effectively remove small samples and make them suitable for expanding the remaining healthy cells. Bone marrow isolated from donor is replicated or preserved for future replication. When bone marrow is stored, it is gradually frozen using a computerized refrigeration unit. For example, samples are taken in equal volumes from fresh bone marrow / blood suspension and placed in sterile Nunc tubes and placed in a beaker of crushed ice until the temperature of 4 ° C. is reached in a cold storage room. A solution is added to each Nunc tube using sterilization immediately before the sample is lost to bring the cold preservatives dimethyl sulfoxide and glycerol to 7% and 5% final concentrations, respectively. The freezing program will begin immediately after loading the sample. Use Refrigeration Program 1 (with CryoMed Model Number 1010 controller).

Using this method, cell viability after cooling and rapid thawing in an 80 ° C. water bath exceeds 90% when analyzed by trypan blue excretion. In addition, at least 80% of the original colony forming unit culture (CFU-C) can be recovered after freezing. An example of a system for driving bone marrow and biological material according to pre-measured temperature and time curves is disclosed in US Pat. Nos. 4,107,937 and 4,117,881. It is desirable to store the liquid nitrogen at -196 ° C, the temperature at which all cell metabolism activity is stopped.

6.2. Formation of 3D Substrate Bulkhead

The stromal cells from the bone marrow flotation are isolated from other bone marrow components. This is accomplished using appropriate known methods. For example, the bone marrow flotation is centrifuged at low speed, ie, 3,000 × g, for 20 minutes to give a white base of cells (ie, buffy coats) including macrophages, fibroblasts, adipocytes, monocytes, reticular cells, endothelial cells, etc. (guffy coat)). Buffy coat cells can be suspended in appropriate media such as FBS, HS, hydrocortisone hemisuccinate and RPMI 1640 medium supplemented with appropriate antibiotics.

The cells are then placed on a three dimensional matrix. When high concentrations of stromal cells are used as the inoculum, the substrate support matrix reaches an appropriate subconfluence level for a short time. For example, about 10 per ml To 10 The stromal cells are placed on a three-dimensional matrix like a sterile nylon mesh in a culture dish or other appropriate disappearance (ie Titer-Tek containers) (Tetko Corp. of New York, New York, USA).

The inoculated mesh is placed in a culture flask containing an appropriate volume of nutrient medium. The three-dimensional culture is suspended and partially precipitated below the medium surface. The culture is incubated at ambient air at a relative humidity of at least about 90% and also at about 5% CO. Stromal cells, primarily fibroblasts, grow along nylon fibers, wrap, and grow into mesh pores. Depending on the concentration of cells used as inoculum, this treatment takes about 5 to 18 days. The subconfluence of the stromal cells is shown in Figure 1 before hematopoietic cell inoculation.

Suspended stromal cells growing in a three-dimensional matrix can be cryopreserved according to the same technique described above for bone marrow cells. To cool the semi-confluent cells on the mesh, round the nylon mesh in a Nunc tube containing appropriate media, such as RPMI 1640 supplemented with cold preservatives such as dimethylsulfoxide and glycerol, with final concentrations of 5% and 15%, respectively. Wrap it up. Stromal cells on the mesh can be frozen at an initial cooling rate of −1 ° C./min at + 10 ° C. to −40 ° C. It is optimal to run at a cooling rate of -2 to 13 DEG C / min until the temperature of the last step is -84 DEG C. In this process about 20-25% of the stromal cells fall out of the nylon mesh.

6.2.1. Strengthening myeloid matrix cell growth

The initial rate limiting factor in the growth of bone marrow stromal cells is the relatively low mitotic index of fibroblasts contained in the bone marrow stromal cells. Growth of these cells and deposition of extracellular matrix components are enhanced by the addition of self-regulated growth factors or hydrocortisone hemisuccinate from the culture of cultured human fetal fibroblasts with high speed cell division.

In addition, adhesion and growth of fibroblasts to the mesh are pre-coated with solubilized collagen types I to IV, or subsets of adult fibroblasts based on their ability to synthesize fibroblasts or any collagen form of the fetal human body. It can be reinforced by using a mesh coated or surrounded by collagen secreted by (hereinafter referred to as growth-enhancing fibroblasts). In this regard, growth-enhanced fibroblasts are enhanced by mild trypsin treatment from the mesh when reaching confluence (5-7 days for fetal human fibroblasts, 14-18 days for adult fibroblasts) and described above. As inoculated with stromal bone marrow cells or cold preserved for future use.

In one embodiment of the invention, growth-enhancing fibroblasts that synthesize matrix components of collagen and other cells grow in the mesh until they reach subconfluence. A mixture of hematopoietic and stromal bone marrow cells is inoculated into the semiconfluent growth enhancing fibroblast mesh network.

Growth, subsetting and cryopreservation methods of growth-enhanced fibroblasts are as follows.

(a) Growth-enhanced fibroblast culture

Incubate growth-enhanced fibroblasts using appropriate methods. For example, RPMI supplemented with 2-10% FBS or 2-10% HS supplemented with antibiotics such as 1 μg / ml hydrocortisone hemisuccinate and 2 μg / ml gentamicin, penicillin, streptomycin, or fungizone Grow fibroblasts in a suitable medium, such as 1640. At ambient temperatures of 35 ° C. to 37 ° C. with relative humidity of at least about 90%, the cultures are grown at about 5% CO.

(b) Subsetting of growth-enhanced fibroblasts

There are a number of methods available for subsetting fibroreinforced fibroblasts. For example, about 5.0 × 10 from a buffy coat of bone marrow flotation. Fibroblasts, endothelial-fibroblasts, or fibroblasts taken from the liver of the body were collected in microtiter wells (1 mm). ), Grow and join. Ca Me Mg Repeated washing 4 to 5 times with no Hanks equilibrium salt solution to separate the cells from the culture well. The matrix remaining on the microtiter plate can be examined by indirect immunofluorescence using monoclonal antibodies against various partition components visualized by direct or indirect labels. For example, enzyme-labeled or fluorescent isothiocyanate-labeled rabbit anti-mouse immunoglobulin G can be used to visualize the binding of unclassified mouse IgG monoclonal antibodies specific for a particular matrix component and therefore present. Collagen type can be confirmed. In many ways counter-selection is possible. For example, suspended cells can activate complement (IgG, IgM) and each is treated with an isotype monoclonal antibody that becomes a specific matrix component (ie, collagen types I to IV, elastin, tropoelastin, or fibronectin). Isolate cell sub-populations capable of synthesizing the product. Subsequent treatment of these cells with guinea pig complement damages or destroys the cells to which the single antibody binds. The surviving cells remaining in the sample are improved by placing them back in the microtiter wells and growing as described above. The effect of the isolation method can be confirmed by examining the matrix secreted by viable cells containing appropriate monoclonal antibodies visualized by direct or indirect labeling techniques.

For optimal growth of hematopoietic cells, the initial matrix should contain collagen III, IV, and I in a ratio of 6: 1: 1.

(c) cold preservation of growth-enhanced fibroblasts

Growth-enhanced fibroblasts can be cryopreserved using methods such as those described above for stromal cells. Similar to stromal cells, growth-enhanced fibroblasts are separated from the mesh during the freezing process. However, this matrix still adheres to myeloid matrix cells, thus reducing the time required to form a matrix that aids hematopoietic cell growth.

6.3. Inoculation with Hematopoietic Cells

Bone marrow cells are suspended in appropriate medium (eg FBS, HS, RPMI / 1640 supplemented with ahydrocortisone and appropriate antibiotics can be used) and inoculated in three-dimensional substrate support. These cells may be fresh or quickly warmed up, for example, in hot water at 80 ° C. in a cold preserved sample. Inoculate the appropriate concentration cells into the semi-conjugated stromal cell mesh network. For example 10 To 10 Cells are injected into a three-dimensional substrate matrix in a 25 mm plastic culture flask and grown in about 33 ° C. to 34 ° C. and 5% CO circulating air. Humidity associated with these cultures should exceed about 90%. After 3 days, the incubation temperature should rise to about 35 ° C to 37 ° C.

Usually, hematopoietic cells will grow in natural pockets formed by semiconfluent stromal cells and progeny cells will remain in the cell adhesion layer. Such adhesive layers are those that are indirectly connected by attaching to cells directly attached to the mesh or to cells directly attached to the mesh. Although hematopoietic colony formation occurs rapidly, substrate inoculation appears to be a rate limiting step in the hematopoietic stage because the inoculum is mainly inoculated in the region with the substrate support matrix. Colony formation occurs in the natural lattice formed by the partially generated substrate layer and also appears on the outermost surface of the matrix. Surface colonies are somewhat smaller than colonies in the matrix and sometimes appear to be part of the non-adsorbed region. In practice they are loosely attached and remain after supply. The cells consistently seen in the monolayer LTBMC are called pseudo-adherent layers (Coulombel et al. 1983, Blood 62; 291-297).

After 4 and 5 days mature granulocytes, monocytes, and erythrocytes appear in the non-adsorbed layer as observed in cytospin preparation. After 7-10 days, a number of hematopoietic colonies can be observed in the mesh lattice and are morphologically compatible with CFU-C mixed colonies and lymphoid colonies. Giant nuclear cell growth is limited but can be observed in such matrices as well. Average 3.6cm The culture produces 450-950 CFU-C per week.

Strains consisting of stromal cells and hematopoietic cells derived from the same individual (Autologos) should be supplied twice a week. Strains consisting of a patient's bone marrow injected into stromal cell meshwork derived from another individual (heterotype) should be fed three times per week to ensure adequate reduction of mature immune-sensitized cells from the non-adsorbed layer.

6.4. Long-term growth of steric bone marrow strains

Optionally, three-dimensional bone marrow cultures can be conjugated with monocytes to enhance long term growth. Peripheral blood mononuclear cells can be prepared from heparinized suspensions using Ficoll-hypaque or Percoll. Peripheral blood cells and bone marrow hematopoietic cells are preferably derived from the same antologous. They are obtained by venipuncture and are stored cold by taking a bone marrow specimen. Another peripheral blood cell can be procured from the patient if necessary during the culturing process. However, if there is a suspicion of metastatic disease, the sample should be purged as mentioned above. Monocytes can be seeded in three-dimensional culture immediately after inoculation into bone marrow cells. For example, 5 × 10 To 10 Mononuclear cells (monocyte subpopulations are the preferred cell type in the mononuclear cell layer for this step) can be inoculated into the meshwork 4,5 days after initial inoculation with myeloid hematopoietic cells and then every three weeks. This process can be observed weekly to improve hematopoiesis by 10-13%.

In our experience, confluent stromal cell strains only support hematopoietic at best. Human hematopoietic progenitors can grow indefinitely if they are provided with the necessary substrate-derived growth / regulatory factors. The tertiary culture system of the present invention allows the stromal cells to remain semiconfluent and thus produce the factors necessary for hematopoiesis for a long time. However, this period can be extended by further manipulation of the tertiary culture system.

For example, an initial bone marrow sample may be divided into multiple aliquots, each about 10 Contains hematopoietic cells. Each of these is inoculated into a subconfluent stromal cell meshwork. Strains can be directly observed using reversed phase microscopy and monitored by differential counting of non-adsorbed cells as seen in cytospin material of the medium used after feeding. Prior to confluence, the strains are treated with collagenase and lightly sonicated for about 6-10 minutes. Hematopoietic and stromal cells isolated from the culture are sorted by density difference method. Hematopoietic cells can be counted using hematopoietic plaques and stored about 50% cold using the method described above. The remaining 50% of hematopoietic cells are about 10 Aliquot the cells to include and inoculate semi-confluent stromal cells. If they join, repeat the same process. This technology allows us to create a continuous bank that (a) provides a microenvironment that produces the necessary growth factors, thereby sustaining the growth of hematopoietic cells, and (b) depositing hematopoietic progenitor cells until a number suitable for transplantation is achieved.

6.5. Hematopoietic Regulation in Three-dimensional Long-term Bone Marrow Cultures

Various cellular components of human bone marrow can be passaged to a third culture as a separate culture. Macrophages, reticular cells, adipocytes and fibroblasts are grown separately and treated with various substances to modify their secretory activity. The regulation of fibroblast activity is described above.

Hematopoieticity in long-term human bone marrow cultures on three-dimensional meshwork can be modulated by the secretion of bone marrow macrophages (Kupffer cells) when grown in culture. Kupffer cells can be isolated from these organ substrates, for example by pronase treatment. In summary, tissue samples are incubated for 1 hour in Pronase solution [0.2% Pronase (Calbiochem) and Geys' Balanced Salt Solution (BSS)]. The pH of such solutions should be maintained at 7.3 to 7.5 using, for example, 1N NaOH. Deoxyribonuclease (0.5 mg; Calbiochem) is added every 30 minutes during this process and the resulting cell suspension is filtered and centrifuged at 350 × g for 10 minutes. Pellets are resuspended with Geys' BSS and mesenchymal cells (macrophages and epithelial cells) are separated from debris and mature blood cells using Percoll (Pharmacia) concentration differences. The resulting cell aliquots should be washed three times for three minutes using modified Dulbecco's medium supplemented with 10% fetal calf serum and about 3-4 × 10 Place in a petri dish in an amount containing canine cells.

After one day of incubation, non-adsorbed cells are washed off with culture medium and adsorbed cells are kept at 33 ° C. in a gas mixture of about 6% CO in an indoor environment of about 80% relative humidity. The growth and secretion of these cells involves (a) converting CO: O ratios, (b) treating the cultures with latex beads, (c) treating the cultures with silica, and (d) prostagla in the medium. It can be promoted by adding Dean E, E or F, and (f) supplementing Interleukin 1 or Interleukin 2 with the medium. Macrophage secretion products can be modulated by these processes / drugs.

Medium conditioned with the secretion products of these macrophages can be used to adjust the long-term bone marrow culture hematopoietic / granulation ratio.

6.6. Use of tertiary bone marrow culture system

6.6.1. transplantation

The tertiary bone marrow cultures of the present invention are used in the treatment of diseases that destroy healthy myeloid cells or suppress their capacity. Such treatment is particularly effective in treating malignant blood and other tumors that metastasize to bone marrow. This feature of the present invention is intended to treat patients whose bone marrow is adversely affected by environmental factors (e.g. radiation, toxins, etc.), chemotherapy and radiation required for diseases that do not directly affect the bone marrow. effective. In these cases, bone marrow cells from healthy patients should be taken out and preserved and regenerated and administered to patients with diseases that directly destroy the bone marrow or adversely affect the bone marrow.

The three-dimensional strain system of the present invention provides several advantages to patients in need of bone marrow transplantation. If a patient receives his or her cells, this is called an autologous transplant, which eliminates the cause of bone marrow transplant rejection, or host rejection of the graft. If the bone marrow contains malignant or diseased cells, the tertiary culture system of the present invention can be used to sweep more effectively than ever before. As described above, an optional method for sweeping malignant or diseased cells is also appropriate for small amounts of bone marrow cells. The three-dimensional culture system described here makes this possible. Thus, a small amount of sample obtained from a patient can be erased more efficiently using an optional method of killing malignant cells without affecting healthy cells. The remaining healthy cells can then be greatly expanded using the three-dimensional culture system of the present invention. In addition, the process of the present invention allows the use of chemotherapeutic agents and radiation to more actively treat renal disease. Currently, such treatments are limited in scope due to the toxicity of the bone marrow.

6.6.2. Patient disease monitoring

In patients with cancer or other diseases, it is effective to monitor the patient's condition by sucking the patient's bone marrow and testing the sample. This method can detect metastasis or reoccurrence before it becomes clinically clear. Patients with other diseases that can be detected by testing bone marrow cells can also be detected in this way.

Long-term growth of cells derived from aspirated but unerased (uncleaned) bone marrow specimens using the tertiary system of the present invention enhances detection of metastatic and hematopoietic cells with chromosomal abnormalities. Such cells will be expanded by asexual reproduction in the tertiary culture system of the present invention and thus will be more easily detected. These cells may not be detected in conventional specimens of freshly absorbed (uncultured) bone marrow.

6.6.3. Compound screening

Cytotoxicity to bone marrow by medicines, anti-tumor agents, carcinogens, food additives and other substances can be tested using the in vitro bone marrow cloning system of the present invention.

First, a safe growth strain of bone marrow cells (including both stromal and hematopoietic cells) is made. The following cultures are exposed to various concentrations of test substance. After incubation with these test substances, they are tested under an microscope to determine the maximum tolerated dose (HTD) of the cultures-the concentration of the test substance when the first morphological abnormalities appear. Cytotoxicity tests can be performed using a variety of chejuvitae dyes to assess cell viability in such steric systems using techniques well known to those skilled in the art. HTD determinations provide concentration ranges for further testing.

Once the test range has been determined, their effects on the viability, growth, and shape of the different cell types by varying the concentration of the test substance and making bone marrow cultures by means known to those skilled in the art. You can test

Likewise, the useful effects of drugs can be assessed using a tertiary culture system in vitro. For example, growth factors, hormones, and drugs that can improve blood cell formation can be tested. In such cases, the test substance is exposed to a stable growth culture. After incubation, the cultures are tested for viability, growth, shape, cell type, etc., which show the effect of the test substance.

Other tertiary cell culture systems detailed in the present invention can be employed for cytotoxicity testing and drug selection. Examples of the use of tertiary bone marrow cultures used in cytotoxicity assays are provided in section 18.

7. Stereoscopic Skin Culture System

The tertiary culture system of the present invention provides in vivo trademark epidermal and epidermal replication in a system comparable to physiological conditions. Cells that replicate in such a system are properly isolated to form morphologically and histologically normal trademark epidermal and epidermal components.

The use of tertiary co-culture systems for the growth of trademark and epidermal cells has several advantages over the single layer systems currently used. This model allows for normal cell-cell interactions and the secretion of natural growth factors, resulting in the same connective tissue networks found in vivo, in particular stromal cells producing specific types and specific collagen. The resulting complete movable meshwork can be implanted and cold-preserved or used as a target tissue in the study of cytotoxic and pharmaceutical mechanisms. This model also allows fibroblast growth with fibroblasts alone or with keratinocytes and black blood cells for full-thickness epidermal equivalents to form epidermal equivalents. All cells in this tertiary system remain metabolically active and divide, which is an advantage that no other model has.

The tertiary epidermal culture of the present invention has various uses, such as being used as a substrate for compound screening, transplantation and skin transplantation, and the study of skin diseases and treatments. For example, a thorough examination of potential toxic chemicals is generally recognized as necessary, and it is clear that there is a need to develop short-term, in vitro sensitive and renewable assays for medicine, cosmetics and food additives. The tertiary skin model described herein allows the use of tissue-equivalents as an analyte and offers the advantage of normal intercellular interactions in systems that closely resemble in vivo conditions.

Skin replacement of the injured patient is necessary. In the United States and Europe, several centers have used human keratinocyte allografts and autografts in culture to permanently cover burns and chronic ulcer wounds (Eisinger et al., 1980, Surgery 88: 287-293; Green et al. , 1979, Proc. Natl. Acad. Sci. USA 76: 5665-5668; Cuono et al., 1987. Plast.Reconstr, Surg. 80: 626-635). These methods are unsuccessful and recent studies have shown blisters and skin destruction in treated implants because one or more connective tissue components formed under the implanted trademark cortex are abnormal (Woodley et al., 1988). , JAMA 6: 2566-2571). The tertiary skin culture system of the present invention provides a skin equivalent of both trademark and epidermis and overcomes the characteristic problems in cultured keratin cell transplantation currently used. In addition to cytotoxicity and skin replacement; Tertiary skin cultivation may be used in a number of industries, including as a model for studying skin diseases, developing new medicines and therapeutic modalities, and as a naturally occurring pharmaceutical ingredient.

7.1. Establishment of tertiary substrate support and formation of epidermal equivalents

Fibroblasts are inoculated in a tertiary matrix, grown and submerged to make epidermal equivalents. In one preferred embodiment of the present invention, fibroblasts proliferate until the entire growth matrix is covered, and fibroblasts continue to divide until the fibroblasts reach confluence because the tertiary culture allows the cells to escape. This is because it prevents contact inhibition. Although any fibroblasts may be used in the inoculum, it is advantageous to use dermal fibroblasts because they deposit the appropriate type of collagen and elaborate other epidermal components. Fibroblasts can be allogeneic or autologous. Skin fibroblasts are readily obtained from cell suspensions prepared by mechanical and enzymatic separation of epidermal tissue. When the cell suspension thus obtained is placed on a plate the fibroblasts will attach more quickly than other cells and can thus grow and merge, lifted by weak enzymatic treatment and incubated in a tertiary matrix as described above.

Once inoculated into the tertiary matrix, the adsorption of fibroblasts is readily visible (eg within hours) and the fibroblasts begin to unfold across the matrix opening within days. These fibroblasts are metabolically active and secrete a matrix of cells and rapidly form epidermal equivalents of active fibroblasts and collagen. About 60% confluence of fibroblasts on the tertiary matrix is required to support the growth of later inoculated epithelial cells.

Fibroblasts alone are sufficient to form a tertiary matrix matrix that acts as an epidermal equivalent, while other stromal cells can be used to culture the tertiary matrix. These include endothelial cells, blood peripheral cells, bone marrow cells, single cell lymphocytes, plasma cells, adipocytes.

7.2. Inoculating epithelial cells into epidermal equivalents

Epithelial cells are incubated in epidermal counterparts to incubate skin of full thickness including both epithelial and epidermal layers. For this purpose, black blood cells and keratinocytes are inoculated simultaneously or sequentially. For example, keratinocytes can be inoculated onto semi-conjugated black blood cells previously inoculated on a matrix matrix.

Black blood cells and keratinocytes may be allogeneic or autologous in relation to fibroblast stromal cells, and from the skin using known procedures such as culturing the skin with digestive enzymes such as trypsin to separate epidermal and epithelial layers. Can be separated. For example, keratinocytes and black blood cells can be separated as follows. For example, tissue samples, such as the epidermis, are cut off so that the entire surface is easily exposed to antibiotics. Tissues are first washed with concentrated antibiotic solution for about 20 minutes, then washed twice for 10 minutes each. Next, the outer part of the tissue is broken into small pieces and placed in a 0.15% trypsin solution (in PBS without calcium or magnesium) and immediately taken out into a new container containing the same trypsin solution (so that all tissues are covered with the solution). Refrigerate overnight at -8 ° C. The next day, the tissue pieces are removed from the trypsin solution and the bent tongs are used to separate the epidermis from the epidermis. The epithelium is placed in a conical tube and the tissue is cut into a single cell suspension using about 0.15% trypsin in PBS (without calcium or magnesium) and the sample is repeatedly aspirated in and out of Pasteur pipettes to perform this process. Black blood cells are selected by centrifugation at 1400 g for about 7 minutes when the sample is in a single cell suspension and resuspended in growth medium or growth medium containing 0.01 mg / ml PMA. Thus, keratinocyte or black blood cell culture can be made. Epithelial cells can be used to suspend and inoculate epidermal counterparts. Alternatively, when the epithelial cell suspension is smeared, the black blood cells and keratinocytes are separated by differential adhesion. The isolated black blood cells are first inoculated into the epidermal equivalents and allowed to grow for several days prior to inoculation of keratinocytes. Such tissues grow rapidly and can be maintained in nutrient media without externally supplied growth factors.

A disadvantage of all skin replacements is the lack of hair follicle cells and sweat and fatty glands in the implanted area. This deficiency eventually results in the loss of the patient's ability to regulate body temperature normally, causing the patient's skin to become severely dry and out of control. To reduce this problem, biopsies are removed from unaffected areas of the skin and implanted into the epidermal equivalents. By strategically positioning them, the gland associated with the biopsy follicle cells is inserted into the implantation site. The biopsy size is about 4 cm to 8 cm and is pulled out using a standard Baker's punch. An equally sized biopsy can be removed from the epidermal graft and replaced with a graft containing follicle cells, thus creating a histologically normal and functionally normal skin and implanted site.

As an example, a three-dimensional skin cell culture system can be made as follows:

(a) Fibroblasts are attached to the mesh and grown for about 7-9 hours to semi-merge and deposit collagen types I and III as described above to enhance the growth of fibroblasts used in the in vitro bone marrow replication system.

(b) The black blood cells are placed on the substrate mesh and grown for about 5 days to quench.

(c) Keratinocytes are inoculated into semiconfluent black blood cells.

In a preferred embodiment of the present invention, the three-dimensional skin cell culture system can be made as follows:

(a) Fibroblasts are attached to the mesh and allowed to grow for about 14 days to join and to deposit collagen I and III.

(b) Fibroblasts are placed on the matrix and allowed to grow for about 5 days to allow semi-incorporation.

(c) Keratinocytes are inoculated into semiconfluent black blood cells.

In particular, embodiments of the present invention, for example, in the case of burn patients, has the advantage of covering the wound immediately after the injury, in this case corresponds to the epidermis (hereinafter referred to as the renal epidermis), mainly composed of fibroblasts The tertiary cell culture according to the invention can be placed on the wound, followed by application of keratinocytes and black blood cells. The renal epidermis is composed of cells that are allogeneic to the patient's self-cognition. Epithelial cells may be allogeneic or preferably patient autologous. The present invention includes the transplantation of live and growable renal epidermis into which epithelial cells can be added in vivo or in vitro, and the patient's own cells can be adapted to diffuse the transplanted renal epidermis.

7.3. Morphological features of three-dimensional skin culture

The morphological feature of the three-dimensional matrix is that the fibroblasts inoculated into the matrix extend across the opening, exhibit matrix deposition and migrate to the grid of the mesh. Figure 1 illustrates the ability of fibroblasts to arrange them in parallel layers between naturally secreted collagen bundles. These fibroblasts divide cells rapidly and secrete proteins. Black blood cells normally grow in a tertiary culture system, show dendritic shape, retain pigments, and retain the ability to deliver pigments (FIGS. 6-8).

Skin with full thickness can be grown in many ways and allows for air interface. Exposing keratinocytes to air causes keratinocytes to differentiate more rapidly and promote more secretion of the stratum corneum, which is critical for skin permeation studies.

The major advantage of this cell culture system over others currently used in skin and transplant studies is that fibroblasts in tertiary matrices maintain metabolic activity in the joined or quasi-conjugated state, as described above, Secrete collagen types I and III. The normal metabolic activity of these cells is useful not only in the study of diseases in which such systems directly affect collagen secretion, but also in studies where the interaction between epidermal and epithelial cells causes pathological alterations consistent with the disease, as well as for cytotoxicity testing. Do it.

7.4. In vivo transplantation

For transplantation, it is desirable to use a three-dimensional matrix of biodegradable materials such as enteric sutures and gelatin. They allow all the advantages of a three-dimensional culture, but allow the transplanted tissue to remain intact and the mesh is naturally broken down and replaced by normal cells that are taken up by the body and migrate to that site.

Preference is given to using dermal fibroblasts obtained from patients to be transplanted to form a tertiary matrix matrix. Or fetal fibroblasts or a mixture of fetal fibroblasts and a patient's fibroblasts may be used. However, according to the invention self-derived, allogeneic or heterologous fibroblasts can be used, and Example 19 demonstrates that human fibroblasts are cultured according to the invention and successfully implanted into pigs. However, it is important to note that epithelial cells seeded later are derived from the patient to minimize the risk of transplant rejection.

In another embodiment of this aspect of the invention, the three-dimensional matrix support matrix that forms the renal epidermis can itself be implanted into the wound of a patient. In this case, the patient's own epithelial cells at the wound site infiltrate the matrix matrix and proliferate on the matrix matrix in vivo, forming both full-thick skin, ie epithelial and epidermal layers. Alternatively, epithelial cells may be inoculated into the renal epidermis and applied to a sheet of epithelial cells. If the wound is large, it is appropriate to implant a complete tertiary skin culture or use a combination of renal skin and full thickness skin strain culture. For example, the renal skin is implanted with a full-thick culture at the edge of the wound and at the center of the wound to promote growth and healing and to minimize scar formation.

7.5. In Vitro Use of Stereoscopic Skin Cultures

Tertiary skin cultures can be maintained in vitro and used for a variety of uses, such as classifying compounds for the study of toxicity, medicinal mechanisms of action, skin destruction and the study of disease.

Tertiary skin cultures can be used as substrates for testing the cytotoxicity of compounds and other materials. For example, for use in cytotoxicity assays, human cells are cut to 6 mm thick and placed in 96-well flat tissue culture microtest plates and fed with appropriate media. The following test substance is added to each sample. Dilution can advantageously make use of the test substance, in which case the concentration range of the toxic substance can be tested. Each tissue type is provided in three lines in the mesh to triple the data. Properly adjusted analysis can proceed as follows: mesh alone; Mesh inoculated with fibroblasts; Mesh inoculated with fibroblasts and keratinocytes; And mesh cultured with fibroblasts, black blood cells and keratinocytes; Chemicals are added to each substrate and incubated for 24 hours. The cytotoxic effects of these substances can be assessed in several ways. For example, a well-known and well-known neutral-red assay can be used. To do this, after removing the medium, each well is washed off and a neutral-red dye 0.4% aqueous stock solution is added. The dye is removed at various time intervals and the cells are quickly washed with 4.0% formaldehyde, 1.0% CaCl. After about 20 minutes, the amount of dye present in each sample tissue can be measured by reading the absorbance with a Dynatech microplate reader equipped with a 540 nm filter. The amount of bio dye absorbed is directly proportional to the number of viable cells in each well. The readings are averaged and the result is the absorbance that appears above the baseline in the reference culture.

Recent studies have shown that skin is an integral and active component of the immune system (Cooper et al., 1987, The mechanobullous diseases. In: Dermatology in General Medicine, 3d, Ed., McGraw Hill, NY, pp 610-626 One major cell in the skin responsible for various immune activities is Langerhans cells. These cells are prepared from new skin samples and added to the three-dimensional skin culture to create an immunologically complete tissue system. It is difficult to grow cells in long term culture using conventional tissue culture techniques. The ability to grow cells in a three-dimensional culture system will be very important in research involving transplantation, cytotoxicity and disease mechanisms. This type of skin culture system has a significant impact on self-immune destruction studies involving the skin, directly or indirectly (such as lupus erythematosus and bullous heredity).

As described above, tertiary skin cultures were used to test sensitivity to allergens. For allergy testing, skin cultures are inoculated with lymphocytes (or plasma cells) and mast cells obtained from patients. Exposing the culture to an allergen that bridges an IgE antibody (generated by lymphocytes) that is bound to mast cells releases vascular active mediators such as histamine by the mast cells. Release of histamine in culture can be measured, which is associated with the body's allergic response to test allergens.

8. 3D Liver Tissue Culture System

Liver cells are isolated by conventional methods (Berry and Friend, 1969, J. Cell. Biol. 43: 506-520) suitable for human liver biopsy or absence of cadaver. In short, the cannula is inserted into the portal vein or portal branch and perfused with a calcium- or magnesium-free buffer until the tissue is free of force. It is then perfused to the organ with proteolytic enzymes, such as collagen enzyme solution, at an appropriate flow rate. This cuts the connective tissue framework. It is then washed in buffer and the cells are scattered. The cell suspension is filtered through a 70 μm nylon mesh to remove debris. Liver cells can be selected from the suspension by 2-3 centrifugation.

To permeate the lobes of the cut human body, HEPES buffer can be used. The perfusion rate of collagen enzyme in HEPES buffer is about 30 ml / min. Single cell suspensions are obtained by further incubation with collagen enzymes at 37 ° C. for 15-20 minutes (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).

The isolated liver cells are then used to culture three-dimensional substrates. The cultured substrate is replicated by culturing in vitro liver cells in situ comparable to physiological conditions as described for bone marrow and skin. This increases functional expression by liver cells.

The liver culture maintained in this way can be used for various purposes, including cytotoxicity testing, drug selection, and the like. In one example, three-dimensional liver cultures were used to screen for carcinogens and mutants in vitro. Many compounds, in particular, do not act as mutants in test organisms such as bacteria and fungi, but are known to cause tumors in laboratory animals such as mice. This is due to metabolic activity, i.e. some chemicals are metabolically altered by enzymes in the liver (oxidase- and hydroxylated P450s) or other tissues, creating new compounds with both mutagenic and carcinogenic properties. do. To identify these carcinogens, a test was devised to culture and screen chemical compounds with liver extracts prior to exposing metabolic products to test organisms (Ames et al., 1975, Mut. Res. 31: 347-364). Although somewhat complicated, Ames's analysis lacks sensitivity. In contrast, three-dimensional liver cultures can be used as both metabolic converting agents and test organisms to determine mutagenicity and carcinogenicity of the substance being tested.

9. Three-dimensional model system for blood-brain gateway

According to the present invention, a three-dimensional tissue culture model system for blood-brain barrier can be made. In short, such stereocultures culture endothelial cells derived from small blood vessels in the brain and join in a three-dimensional mesh to regenerate the endothelial cell barrier, which separates the central nervous system from the bloodstream. First, astrocytes and neurons feed to the confluent matrix formed by endothelial cells, allowing endothelial cells to form a barrier between the culture surface above and the neurons below. Substances applied to the endothelial cell surface must pass through the endothelial layer to reach the neurons below.

For example, endothelial cells can be isolated from small brain blood vessels according to Larson et al. (1987 Microvasc. Res. 34: 184) and their numbers can be expanded by incubation in vitro using standard methods. These small vascular endothelial cells are then inoculated into a suitable mesh (e.g., nylon filtration screens made by Tetko, Inc., # 3-210 / 36) and grown to reach confluence and using silver stain Identify the presence of hermetic junctional complexes specific to the small vascular endothelium and associated with endothelial gateway function.

Neurons and astrocytes are obtained from the next embryo or pre- and postpartum mice and separated from each other using standard techniques (Hattan et al., 1988. J. Cell. Biol. 106). For example, neurons are separated from astrocytes by differential adsorption to the substrate, and the stellate cells are attached to a culture dish precoated with 100 μg / ml poly-D-lysine and the neurons precoated with 500 μg / ml poly-D-lysine. Attached to the prepared culture dish.

Astrocytes are seeded in the confluent endothelial tertiary matrix matrix and incubated for about 5 days and inoculated together again into neuronal cells.

The multi-layered three-dimensional tissue culture system includes one layer of small vascular endothelial cells and another layer of astrocytic cells and neurons, and regenerates the blood-brain barrier structure found in vivo, where the blood material is the endothelial of the small blood vessels. Pass through to reach the neuronal tissue of the brain. This system is used to test the ability of a substance to cross the blood-brain barrier. Since many materials cannot pass through these barriers, there is a need for long felt to quickly screen the permeability of the test material in the test tube. For example, many antibiotics cannot cross the blood-brain barrier. Will be useful for quickly screening newly developed antibiotics for permeability; Relatively few antibiotics are used to treat central nervous system infections, most of which are related to penicillin and are associated with allergic reactions and the development of new CNS-active agents is urgent.

10. Three-dimensional Pancreas Tissue Culture System

Pancreatic leaflet cell suspensions are prepared using techniques described by: Ruoff and Hay, 1979, Cell Tissue Res. 204: 243-252; and Hay, 1979, in Methodological Surveys in Biochemistry.Vol. 8, Cell Populations.London, Ellis Hornwood, Ltd., pp. 143-160). In short, tissue is chopped and washed in calcium free, magnesium free buffer. Finely chopped tissue debris are incubated in a solution of trypsin and collagen enzyme. The isolated cells are filtered using 20 μm nylon mesh and resuspended in appropriate buffer, such as Hank balance saline solution, to make pellets by centrifugation. The resulting cell pellet is resuspended in a minimum amount of appropriate medium and seeded into the prepared three-dimensional substrate as described above. Such mesenchymal cells can be identified based on enzymatic elemental incorporation. Incubation of pancreatic lobe cells in the tertiary matrix system prolongs cell survival in culture.

EXAMPLE

11.Examples: Three-dimensional Bone Marrow Culture System

One of the following sections can be used to create long-term bone marrow cultures for use in humans, non-human primates and mice using a three-dimensional culture system. Tertiary cultures can be evaluated by injecting an electron microscope, and the cell contents can be evaluated using a number of methods. Progenitor cell contents are assessed by CFU-C and BFU-E and cell contents are assessed by differential hemocytosis and by cell flow analysis using monoclonal antibodies labeled specifically for different hematopoietic cell lines.

The results show that the three-dimensional culture system supports multiple blood tissue lineages, as evidenced by the non-adsorption and adsorption zone differential hematology of human, primate and mouse cells. Cytofluorograph analysis of the cells attached to the tertiary substrate, ie the adsorption zone, reveals the presence of early and late bone marrow precursors, mature granulocytes, B and T lymphocytes, megakaryocytes / platelets and unicellular / macrophages. Although progenitor cells located within the matrix are variable, it is derived from a random population of stromal cells used to form the support matrix.

Because hematopoiesis depends on growth-related activity and factors produced by support cells, tertiary cultures are grown in flasks containing stromal cells in confluent monolayers. It can be seen that hematopoietic and stromal cell growth in tertiary cultures is limited when confluent stromal cells are present. That is, the confluent monolayer of stromal cells in the flask appears to shut off the tertiary culture system. Hematopoietic recovery is observed when the tertiary culture is transferred to a new flask. These results indicate that stromal cells affect not only hematopoietic cells but also other stromal elements.

The methods, results and data are described in more detail in the following sections.

11.1. Preparation of Bone Marrow Samples

11.1.1. Bone marrow of the human body

Bone marrow is aspirated at various sites on the posterior iliac crest of hematopoietically normal adult volunteers after obtaining informed consent. Samples are collected in heparinized tubes and suspended in 8 ml of RPMI 1640 medium conditioned with 10% FBS and 5-10% HS and added hydrocortinone, Hunzizone and streptomycin. 5 × 10 scattered cell population Divide into cell aliquots with dog nuclei.

11.1.2. Non-human Primate Bone Marrow

Primitive synomagus monkey monkey femurs were purchased from the Charles River Primate Center (Porter Washington, NY). The phalanx of the femur was removed from the bone in sterile condition. Remove the red bone marrow and suspend in the medium 5 × 10 Aliquot into cells that constitute the nucleus of the dog.

11.1.3. Mouse bone marrow

Adult male Long-Evnas mice (225-400 gm) are anesthetized with ether to remove these femurs, and blood is drawn from the abdominal aorta using a heparinized syringe. Splitting the femur to the bone marrow contents with 10% FNS and 10% HS and Fischer medium with hydrocortisone, fungizone, heparin and antibiotics (Naughton et al., 1987, J. Med. 18: 219-250) Gibco, NY) scrape into a culture ground containing 3ml. 5-7 × 10 Prepare an aliquot of the cell.

11.2. Generation of 3D Substrate Matrix

Nylon filtration screens (# 3-210 / 36, Tetko Inc., NY) were used as templates to support all LTBMCs described in the examples below. The screen was assembled in a square knitting pattern with a diameter of 90 μm and a hole of 210 μm. Stromal cells were seeded according to the protocol described in the following sections. Adsorption and subsequent growth of substrate elements were monitored by using an inverse contrast microscope and scanning with an electron microscope (SEM).

11.2.1. Screening and inoculation of stromal cells for human LTBMC

An 8 mm x 45 mm screen was immersed in 0.1 M acetic acid for 30 minutes and treated with a 10 mM polylysine suspension for 1 hour to enhance support cell adsorption. They were placed in a sterile petri dish and 5 × 10 Inoculate human bone marrow cells or equivalent human fetal fibroblasts (1M 1380, Coriell Institute, NY). Human fetal fibroblasts were singled using RPMI 1540 medium conditioned with 10% FBS, 5-10% HS and added hydrocortisone, fungizone and streptobis at 35 ° C., 5% CO and at least 90% relatively moist state. Grow into confluence layer. These cells were selected using collagenase (10 μg / ml for 15 minutes) and transferred to the screen. After 1-2 hours incubation at 5% CO Place in culture flask and float in additional 5 ml medium. Screens inoculated with bone marrow stromal cells were transferred in a similar manner.

11.2.2. Screening and inoculation preparation of stromal cells for non-human primate LTBMC

Two matrices were used for LTBMCs of monkey cells. Human fetal fibroblasts were inoculated in nylon mesh (as described above) and 5 × 10 from cynomalgus monkeys. Femoral bone marrow was inoculated into nylon mesh. Culture conditions and screen pretreatment protocols are the same as those for human culture described above.

11.2.3. Screening and inoculation of stromal cells for mouse LTBMC

The 8 mm x 45 mm nylon screen was immersed in 0.1 M acetic acid for 30 minutes and coated with molten type IV rat collagen (GIBCO Labs, NY) for 1-2 hours. 5-7 × 10 on the screen After inoculating bone marrow cells of Long-Evans rat femur and incubating for 1-2 hours in 33% 5% CO, the mesh was 25cm Transfer to culture flask. 5 ml of medium is added to float the screen.

11.3. Inoculation and Culture of Hematopoietic Cells into 3D Matrix Matrix

When approximately 70% of the mesh pores were bridged into support cells (10-14 days for mouse stromals, 7-13 days for human or monkey substrates, and 4-7 days for human fetal fibroblasts), the screen was sterilized. Transfer to a plate and 5 × 10 Bone marrow cells or 2-5 × 10 cells with the nucleus of a human body or monkey Each mouse was inoculated with fetal femoral cells. After 2 hours incubation in 5% CO, each screen is 25 cm with 5 ml of medium It was slowly suspended in Corning flask. The culture is fed every 5 days by replacing the used medium with fresh medium. Culture vessels were also examined for the appearance of a single cell layer on the vessel wall. If such monolayers joined more than 225%, the tertiary culture was transferred to a new flask.

11.4. Evaluation of Three Dimensional Bone Marrow Culture

Growth of myeloid cells and cell content of steric cultures were analyzed histologically by differential coefficients CFU-C and BFU-E assays and cytofluorograph analysis described below.

11.4.1. Histological analysis

For electron microscopy studies, the cultures are detached at various intervals following the inoculation of the first stromal cells and the second hematopoietic cell inoculation. In brief, the nylon screen is cut into approximately 4 equivalent portions, fixed in 3% gluter aldehyde phosphate buffer solution, washed, dehydrated in acetone, and placed in a Denton Critical Point Dryer. In some cases, the stratum corneum can be physically destroyed to show underlying cell growth (Naughton et al., 1987, J. Med. 18: 219-250). Samples were coated with 60% gold and 40% palladium and studied by Amray SEM.

The growth pattern of human and monkey cells in tertiary LTBMC was similar to that of mouse bone marrow. In brief, stromal cells (derived from bone marrow or derived from fetal fibroblasts) grow linearly, enclosing each nylon strand and extending into mesh pores (Figure 1). Hematopoietic (and stromal) cells of the second inoculation inoculated into the natural lattice formed by the stromal cells are 3.6 cm Proceed to about 70% of the holes in the mesh (Figure 2). Hematopoietic cells do not bind directly to nylon but appear to bind to the site where the support cells attach. Colony formation is evident in all cultures 3-6 days after the second inoculation of hematopoietic cells. To express hematopoietic, myeloid and other colonies, a 210 μm body provides a sufficient site (Figure 2). Hematopoietic cells are observed on the outer surface of nylon screen LTBMC but are most widespread in the supporting cell lattice that occur.

11.4.2. Total Cell Count and Cytospin Analysis in the Used Medium of Tertiary LTBMC

Total cell counts and cytospin analysis were performed using the removed medium after the culture was fed (every 5 days). Cytometry is performed using the hemocytometry method. Cytospins are colored with Wright's-Giemsa and randomly counted. Analyzes of cytospin slides are prepared after each feed reveals the presence of later stage precursors of erythroid, myeloid and inlet permeation lines in human and monkey cultures (Table 2). Although the cell types varied, the incubation periods of the various tested species (39 weeks for mice and 12.5 weeks for primates) were consistent. Macrophages / monocytes / fibroblasts released into non-adsorbed sites of human culture increase over time, primarily at the expense of myeloid cells (Table 2).

11.4.3. Computational site total cell count and cytospin analysis of stereoscopic LTBMC

Adsorbed site cell numbers were performed by treating the screens at different time intervals with a collagen enzyme and trypsin 1: 1 mixture (10 μg / ml) and weak ultrasound. This adsorption site analysis of human and cynomalgus monkeys LTBMC showed that the relative ratio of stromal cells to hematopoietic cells increased over time in culture (Table 3). In particular, as hematopoietic colonization progressed, the relative proportions of substrate elements decreased. However, in the later period of LTBMC stromal cells grew at the expense of hematopoietic cells.

Cell proliferation took steady state after several weeks in culture; When LTBMC was tested on a weekly basis, a similar number of cells were found in the adhesive and non-adhesive regions (Figure 3). In the first 1 to 2 weeks of culture, the cell numbers in the non-adsorption zones were somewhat wrong. They fall off easily, resulting in a significantly higher cell count in the non-adsorption zone. Similarly, due to the relatively low inoculation efficiency, the inoculation volume is 5 × 10. 5 × 10, even in cells To 10 Only cells initially adhere to the mesh. This masks 2-3 times the cell proliferation that occurs in the mesh during the first week of culture.

11.4.4. CFU-C and BFU-E Contents of Adhesion Region of 3D LTBMC

The CFU-C content of the adhesion region of rat LTBMC was determined by modifying the method of Bradley and Metclaf (1966, Austr, J. Exptl. Biol. Med. Sci. 44: 287-300). In short, 4 × 10 Cells were plated and incubated at 37 ° C. in 7-7.5% CO. Colony-stimulating activity (CSA) on CFU-C of rats counted after 14 days in culture was measured using splenocyte conditioned media of Pokeweed mitotic substance mice. Human CFU-C is 10 per ml in Iscove's Modified Dulbecco's medium supplemented with 20% FBS Aliquot into cells with nuclei and 10 in 0.5% agar Human CFU-C was measured by plating on layers of PBLs (Griffin et al., 1981, J. Clin. Invest. 68: 932). Colonies were evaluated on days 7 and 14 after plate (37 ° C. at 7% CO). Human BFU-E 30% FBS, 1% Bovine Serum Albumin, 10 M mercaptoethanol, 2.5-5 I. U / ml, partially purified human urinary erythropoietin (Naughton et al., 1985, J. Surg. Oncol. 30: 184-197) and 4.5% phytohemagglutin LTBMCs were tested at multiple intervals with 0.8% methylcellulose in Iscove medium containing stimulated human leukocyte controlled medium (Cashman et al., 1983, Blood 61: 876-884).

A significant number of CFU-Cs were recovered in the adhesion regions of rat and human LTBMCs related to those present at the initial inoculation (Figure 4). Preliminary findings indicate that BFU-E persists in human LTBMCD (Table 4).

11.4.5. Cell Fluorescence Photography of Cell Contents of 3-D LTBMC Adhesion Regions

Cytofluorescence analysis of the cell content of the adsorption region of human and monkey LTBMC was carried out using EPICS system (Coulter Electronics, Hialeah, Fla). Cells were separated from nylon mesh using collagenase enzyme and trypsin, washed well and inoculated with hematopoietic cells at various intervals. Then Ca cells Me Mg Incubated in Hank's salt solution for 45-60 minutes. They reacted with monoclonal antibodies conjugated to fluorescent isothiocyanates (FITC) from Mo01, T-3, B-1, Plt-1 and MY-9 (Coulter Immunology, Fla). IgM-FITC-treated cells of guinea pigs were used as reference. The classification window was selected from the criteria of fluorescence and optical scanning histogram. The 0.255 window was approximately sweet and the cell profile was measured.

Cytofluorescence analysis of adhesion regions in human cultures at 2,7 and 10.5 weeks showed early (MY9) and late (Mo-1) myeloid cells, B (B-1) and T (T-3) lymphocytes, megakaryocytes The presence of platelets (Plt-1) and single cells / macrophages (Mo-1) was confirmed (Table 5).

Human and monkey LTBMCs could form in the layer of fibroblasts of the human fetus, but this matrix does not support the growth of rat LTBMCs. Fetal fibroblasts reach a subconfluence stage that allows for continuous inoculation of bone marrow cells much faster than the bone marrow matrix. The phenotypic profile of the adsorption region when the red marrow's bone marrow grows in the supporting structure of fetal fibroblasts responds more to Plt-1 antibodies than other cultures studied, but also shows other hematologic lineages (Table 5). It is not known to what extent these findings reflect displacements in cell populations of fetal cell-mediated adsorption regions or cross-reactivity of antibodies.

11.4.6. Effect of Confluent Stromal Cell Monolayer on Cell Growth in Three-Dimensional Cultures

Femoral bone marrow cells from Long-Evans rats or cynomolgus red monkeys were harvested through a packed Fenwal column as described by Boswell and co-workers (Boswell et al., 1987, Exptl. Hematol. 15: 46-53). Spilled. In short, 10 -10 Femoral bone marrow cells were placed in 4 ml of medium and poured onto a nylon hair column pre-incubated for 45 minutes at 37 ° C. in the medium. For 45 minutes, after further incubation, non-adsorbent cells were drained and adsorbed cells were washed off strongly and removed by eluting with EDTA-Versene solution (1: 5000 in saline, GIBCO, Grand Island, NY). About 10 25cm cells The flasks were inoculated side by side and grown to 50% to 100% confluence. Pre-formed nylon screen LTBMCs, standardized over time after the second inoculation, were inserted into each flask. Growth on monolayers with nylon screen LTBMC was observed microscopically. Cell counts and cytospins in the non-adsorbed region were performed every 5 days. Differential coefficients of cytospin products of the enzyme-dissociated adsorbed cells were performed 5 days after insertion of the nylon screen LTBMC.

When confluent stromal monolayers were co-cultured with nylon screen LTBMC, both hematopoietic and stromal cells grown in suspended cultures had no adhesive substrate (less than 0.05) or stromal cells at approximately 50% confluence. Inhibition was compared to LTBMC suspended in flasks (p less than 0.05) (Table 6). Co-culture with confluent substrate monolayer also caused detachment and release of mesh-associated stromal cells into non-adhesive regions. Hematopoietic colonies fused and stopped growing. If LTBMC is transferred to a new flask, recovery of hematopoiesis occurs on 3-5 days.

12. Example: Three-Dimensional Skin Culture System

The following subsections describe the three-dimensional culture system of the present invention for culturing skin in vitro. Briefly, cultures of fibroblasts were formed on pre-sterilized nylon mesh. Adsorbed fibroblasts within 6-9 days of culture began to grow into mesh pores and precipitated bundles of collagen. Indirect immunofluorescence using monoclonal antibodies also showed a predominantly Form I collation with several Form IIIs. After 7 days co-cultures of human black blood cells and keratinocytes were plated on the fibroblast mesh. No TPA or cholera toxin was added because nutrients are produced in semi-conjugated fibroblasts in the adsorption layer. Electron microscopy studies revealed skin cells with normal morphology and cell-cell adhesion.

12.1. Formation of three-dimensional substrate

Dermal fibroblasts were isolated with skin tissue, trypsinized for 2 hours and separated into suspension by physical means. Fibroblasts 25cm Falcon tissue culture dishes were grown, joined, and supplied RPMI 1640 (Sigma, MO) supplemented with 10% fetal bovine serum (FBS), fungizone, gentamycin and penicillin / streptomycin. Lightly trypsinize the fibroblasts to plate the cells onto a nylon filtration mesh and the filtered fibers are collected in a square fabric having a diameter of approximately 90 μm and a mesh hole of 210 μm (Tetko, Inc., NY). The mesh is washed with weak acid, pretreated and incubated in polylysine and FBS. Adsorption of fibroblasts occurs within 3 hours and fibroblasts cross the mesh hole within 5-7 days after initial inoculation. These fibroblasts are metabolically active, secrete extracellular matrix and form skin equivalents composed of active fibroblasts and collagen. 1 is a scanning electron micrograph showing the extension of cell treatment over fibroblast adhesion and mesh openings.

12.2. Inoculation of black blood cells and keratinocytes

Black blood cells were isolated using the method of Eisinger and Marko (1982, Proc. Natl. Acad. Sci. USA 79: 2018-2022). Briefly, skin samples are incubated for 4-6 hours in trypsin to separate epidermal and skin layers. Epithelial cells are suspended in medium and 25 cm The Falcon tissue culture flasks were plated. Black blood cells were isolated from keratinocytes. Isolated black blood cells are plated on fibroblast-coated nylon mesh and grown for 3 days before keratinocytes are added. Black blood cells normally grow in these systems, create dendritic processes in the genus, still retain the pigment, and retain the ability to transfer the pigment to keratinocytes. 6 shows the appearance of black blood cells after 3 days in a three-dimensional culture system. Isolated keratinocytes were plated on black blood cells after 3-4 days. This tissue grows rapidly and is maintained in RPMI 1640, 10% FBS and appropriate antibodies. As external growth factors are secreted by skin elements, externally supplied factors (eg, TPA, cholera toxin, etc.) (as described by Sengel, 1983, in Biochemistry and Physiology of Skin, Vol. 1, pp. 102-131, oxford Univ, Press, NY; and Eisinger et al., 1988, Proc. Natl. Acad. Sci. USA 85: 1937-1941).

12.3. Histological Analysis of Skin Cultures

Skin cultures were evaluated histologically using light microscopy using the following method; All tissues are fixed in 2.5% buffered gluteraldehyde, dehydrated in ethanol, washed with xylene and placed in paraffin. The sections were cut to a thickness of 6-8 μm, stained with hematoxylline-eosin and examined for normal and altered morphological properties.

Cross sections of the skin model are shown in the micrographs of FIGS. 7 and 8. Normal cell arrangement and morphology are clear. Epithelial and skin components completely surround the mesh fibers, and a distinct skin-skin bond is evident (Figure 7). Keratin cells have a normal form, contain pigment particles, and cell maturation is evidence of the formation of keratin (FIG. 8).

12.4. 3D skin transplantation in vivo

Transplantation studies in rats show that this three-dimensional system allows the skin and the skin to bond quickly without rejection.

Twenty four rats were used in the skin transplantation study. The mesh is cut into 6 mm round pieces, steam sterilized, treated with weak acid, cultured with collagen IV, incubated with fetal bovine serum and seeded with stromal cells with or without secondary keratinocytes. A mesh covered with skin and epithelial cell components was sutured to the wound and examined closely every 12-24 hours as follows; Rats were lightly ether anesthetized, their back surfaces were shaved and washed with betadine solution. Four 6 mm punches were made using a disposable Baker punch biopsy needle and the implanted mesh was held in place using small-epidermal sutures. Mice were closely tested until 12 hours after surgery and then monitored every 24 hours.

The area of mesh graft showed no signs of erythema, swelling, exudate or fragility. Meshes were removed 7, 14 and 21 days after implantation. The results of this transplant are described in Figures 9 and 10. All skin cells were shown 7 days after transplantation (FIG. 9). 10 illustrates keratinocytes (k) fibroblasts (f), collagen (c), adipocytes (a) and lotus root cells (s), all of which have a native array around nylon mesh fibers (m). There is no rejection in vivo due to the strong natural adsorption of cells on the mesh and the absence of lymphocytes and other immune components.

A parallel study was performed in which a mesh with skin and epithelial components was implanted into a 10 mm x 10 mm skin biopsy and then maintained in culture for 14 days and histologically examined. Similar cell migration, adherence, and differentiation patterns were also observed in these in vitro implants. Grafting studies to date help to substantiate the hypothesis that their three-dimensional substrate system, in which all cellular components are activated and natural growth factors are produced, is a realistic physiological system.

Although the invention has been described in detail with respect to these specific embodiments, it will be appreciated that various changes can be made without departing from the spirit of the invention as described above and in the claims that follow.

13. Example: Three-dimensional liver culture system

13.1. Materials and methods

13.1.1. anesthesia

0.3 ml of injectable pentbarbital sodium was injected into the intraperitoneal cavity of grown Long-Evan mice weighing approximately 300 gm.

13.1.2. Anatomy

The animals are picked up with sharp tweezers to ensure proper anesthesia. A central line incision is made between the examination process and the groin area, followed by an additional incision to allow the flap to enter the cavity of the abdomen. The intestines and other organs were pushed to the right of the animal to expose the portal portal gate of the liver. The portal vein of the liver is dissected and reexposed, and 4.0 sutures are tightened around the vein end of the portal vein of the liver and a catheter is placed there. A second suture is placed around the venous base of the portal vein of the liver and a catheter is placed there. A small gauge was made in the portal vein of the liver using a 21 gauge needle. Run the peristaltic pump and inject 500 ml HEPES buffer (containing 4.1 gm NaCl, 0.25 gm KCl, 3 ml of 1 M NaOH ac 10 ml 0.24% w / v HEPES strain); Immediately afterwards, the lower vena cava is cut out of the buffer solution. After completion of the infusion, stop the pump, remove the liver and place it in a Buckner pennel, followed by collagenase solution (0.4 gm NaCl, 0.05 g KCP, 10 ml HEPES species (above), 0.07 gm CaCl2HO, 6.6 ml 1M NaOH , 50mg collagen in 100cc at pH 7.6 at 37 ° C). Perfusion continued for 15-20 minutes. The contents of the Buckner Fennel were filtered, liver removed and placed in a collagenase solution containing 1.5% (w / v) BSA.

13.1.3. Cell solution preparation

The perfused liver lobe was separated and the outer parenchyma was removed. The medial parenchyma is then physiological And Mg Hanks balanced salt solution (HBSS) containing. Settle the large liver tissue fragments, centrifuge the cell suspension through Percoll gradient (5 ml of DMEM and 0.5 Iu / ml insulin infusion, 0.007 mg / ml glucagon and 20% fetal serum) and place in a 50 ml conical centrifuge tube. HBSS and Physiological Ca And Mg Was added to 50 ml label and 5 ml of Percoll working solution [70% preservation Percoll + 30% PBS; Preserved Percoll [9 parts Percoll and 1 part 10X concentrated Dulbecco's medium] was centrifuged at 800 g for 10 minutes and placed on top of HBSS. Liver parenchymal cells were harvested from the bottom of the slope and added to a three-dimensional mesh culture with a subconfluent substrate.

13.1.4. Preparation of Three-dimensional Substrate Matrix

Nylon filter screen (# 3-210 / 36, Tetko, Inc., NY) 8 mm x 45 mm pieces were immersed in 0.1M acetic acid for 30 minutes and treated with 10 mM polylysine suspension for 1 hour. This mesh was placed in a sterile culture dish and 1 × 10 collected from rats. Fibroblasts were seeded in DMEM complete medium. Corning 25 cm after 1-2 h inoculation at 5% CO Place in a tissue culture flask and add additional 5 ml medium at 3 day intervals to allow for suspension and subconfluence.

13.1.5. Maintenance of 3D Liver Tissue Cultures

After inoculation of hepatic parenchymal cells into the three-dimensional matrix matrix, the cells were maintained in 5% CO in a 37 ° C humidified atmosphere in DMEM medium and fresh medium was fed every three days.

13.2. Results and discussion

The grown hepatocytes cultured in this form showed activity against mitosis and continued to secrete protein for more than three weeks. Hepatocytes themselves were arranged into the cell's cord (Figure 11) and during the first 10-12 days of three-dimensional culture histologically resembled hepatoblasts or regenerated hepatocytes (Figure 12). Because cultures are highly confluent, parenchymal cells begin to resemble bile duct cells, Kupfter cells resemble mature hepatocytes, and other numbers of hepatic stromal cells. Cells were split approximately every 24 hours during the first 10-12 days of culture and continued to split every 72 hours for up to three weeks. Albumin is secreted over three weeks of culture and hepatocytes carry enzymes that are activated to metabolize their products in vitro. After the cultures have reached complete confluence they can remain as live substrates for up to 12 weeks.

14. Example: Three-dimensional mucosal epithelial tissue culture system

14.1. Materials and methods

14.1.1. Preparation of mucosal epithelial cells

Oral mucosal tissue samples were obtained from orthodontic specimens. Tissues were washed with fresh MEM containing antibiotics (2 ml antibody antifungal solution taken from GIBCO, Cat. # 600-5240 AG; GIBCO per 100 cc MEM, 0.01 ml gentamicin taken from Cat. # 600-5710 AD) , Cut into small pieces, then washed with 0.02% EDTA (W / V), 0.25% trypsin (Ca Or Mg To PBS without); After a few seconds, this piece of tissue is removed and fresh 0.25% trypsin (Ca Me Mg In PBS) and refrigerated overnight at 4 ° C. The tissue was then removed and placed in fresh trypsin solution and gently stirred until the cells appeared to form a single-cell suspension. Subsequently, the single cell suspension was diluted with MEM containing serum of fetal bovine inactivated by 10% heat treatment, and centrifuged at 1400 g for 7 minutes. The supernatant was discarded and pellets containing mucous epithelial cells were placed in the inoculation medium. The medium consisted of 2% Ultrocene G, 1 × L-Glutamine, 1 × Non-Essential Amino Acids, Phenylsyrine and Streptomycin. The cells were then inoculated into a three dimensional matrix (see below).

14.1.2. Preparation of 3D Substrate Matrix

The three-dimensional matrix matrix used for the culture of mucosal epithelium was subjected to the three-dimensional liver culture in Section 13.1.4 using 8 mm x 45 mm pieces of oral fibroblasts and nylon filtration screen (# 3-210 / 36, Tetko Inc., NY). It occurred as described.

14.1.3. Maintenance of three-dimensional mucosal epithelial tissue culture

Mucosal epithelial cells were inoculated on the three-dimensional matrix matrix and the cultures were maintained at 37 ° C., 5% CO in DMEM complete medium, and fresh medium was injected every three days.

14.2. Results and discussion

13 is a cross-sectional micrograph of a three-dimensional mucosal epithelial tissue culture prepared by the method described above. This tissue culture was found to outline the stratified outer sheath of the oral mucosa in vivo; As the cells approached the surface of the culture, the nuclei were flattened and arranged in planes parallel to the surface as they occur in vivo.

15. Example: 3D Pancreatic Tissue Culture System

15.1.1. Preparation of Pancreatic Stem Cells

Pancreatic progenitor cells (Ruoff and Hay (1979, Cell Tissue Res. 204: 243-252) and Hay (1979 in Methodological Surveys in Biochemistry, Vol. 8, Cell Populations, London, Ellis Hornwood, Ltd. pp. 143-160 The tissues were harvested from mature male Long-Evan rats and washed with HBSS buffer without chopped calcium and magnesium Crushed tissue solution containing 0.25% trypsin and collagenase Dissociated cells were filtered using a 20 μm nylon mesh, resuspended in HBSS and pelleted by centrifugation at 300 g for 15 min .. The regenerated pellet was resuspended in a small amount of DMEM medium and placed on a three-dimensional substrate. Inoculation (see below).

15.1.2. Preparation of 3D Substrate Matrix

Three-dimensional substrate templates used for pancreatic tissue culture were grown as described above for three-dimensional liver cultures in section 13.1.4 of mouse pancreatic fibroblasts and nylon filtration screens (# 3-210 / 36, Tetko, Inc.). , NY) is made using 8mm × 45mm pieces.

15.1.3. Maintenance of Three-Dimensional Pancreatic Tissue Cultures

After inoculation of pancreatic progenitor cells into the three-dimensional matrix, the cultures were maintained at 37 ° C., 5% CO in DMEM complete medium and fresh media was injected every three days.

15.2. Results and discussion

14 is a cross-sectional micrograph of three-dimensional pancreatic tissue culture prepared by the method described above. Tissue cultured progenitor cells can also be identified based on enzyme source droplet inclusions (arrows) as compared to more homogeneous appearance of stromal cells (asterisks). Islet cells remained concentrated in the center of each mesh hole, 1-2 × 10 A structure comprising insulin-secreting cells was formed.

16. Example: Three-dimensional model system for blood-brain barrier

16.1. Materials and methods

16.1.1. Preparation of Small Vascular Endothelial Cells

Small canal endothelial cells isolated from the brain were cultured in vitro using T-75 tissue culture flasks according to the method of Larson et al. (1987, Microvasc. Res. 34: 184). Cells were maintained in Dulbecco's modified Eagle's medium / Hams-F-12 medium combination (this solution is commercially available as a 1: 1 mixture). The medium was heat treated at 20% to supplement serum inactivated fetal bovine serum (FCS), glutamine and antibiotics. Cells were seeded at a concentration of 1 × 10 cells per flask and reached confluence within one week. The cells were passed once a week and injected once a week with DMEM / Hams-F-12 containing FCS, glutamine and antibiotics as described above. To passage the cells, the flask was placed in 5 ml PBS (Ca Or Mg Without) and trypsinized with 3 ml 0.05% trypsin and 0.53 mM EDTA. The cells were pelleted, resuspended, tested for viability by trypan blue extrusion, inoculated and 25 ml of DMEM / Hams-F-12 supplemented medium was injected. Positive endothelial cells were positively identified using antigen-associated factor VIII (Grulnick et al., 1977, ann.Int. The complex was identified.

16.1.2. Preparation and Inoculation of Mesh

Nylon filtration screen mesh (# 3-210 / 36, Tetko, Inc., NY) was prepared as described above for tissue culture systems such as liver, pancreas, bone marrow, and the like. The mesh is immersed in an acetic acid solution (1 ml glacial acetic acid and 99 ml of distilled water) for 30 minutes, rinsed with the same amount of distilled water, and then steam sterilized. The mesh was covered with 6 ml of fetal bovine serum per 8 × 8 cm mesh and incubated overnight. Stack this mesh to three heights, 3 × 10 Small vascular endothelial cells (cultivated as described above) were inoculated onto the stacked mesh and incubated for 3 hours at 37 ° C. at 5% CO in a humidified atmosphere. 10 ml DMEM / Hams-F-12 was injected every 3-4 days until the inoculated mesh reached full confluence (after approximately 2 weeks).

16.1.3. Preparation of Neurons and Astrocyte Populations

Neurons and astrocytes were isolated from the cerebellum of mice. The cerebellum taken from five rats was dissected and placed in PBS buffer. PBS was removed and 1 ml trypsin solution (10 mg trypsin, 1 ml PBS with 0.01 g MgSO-7HO and 6 μl 1N NaOH) was added to each. After 3 minutes the tissues were rinsed with 2 ml of preservative solution containing about 1 ml PBS buffer and 7.5 mg DNAse and 15 ml Earles BME. Individual cells were transferred into suspension by aspirating tissue through gradually smaller needles ranging from 18 to 25 gauge until solution became cloudy. The resulting single cell suspension was centrifuged at 800 g for 5 minutes and the cell pellet was resuspended in medium and passed through a 33 μm filter. Cells were then placed on 60% / 35% Percoll slopes and centrifuged for 800g for 10 minutes. The cells at the 0% / 35% interface are mostly glia and astrocytes; Most of the cells at the 35% / 60% interface were neurons. Both groups were harvested, diluted separately with 5 ml PBS, washed, and harvested by centrifugation at 2500 g for 5 minutes. Cells were re-suspended in medium (BME containing horse-serum inactivated by 10% heat treatment). Both cell types were plated separately in poly-D-lysine coated petri dishes. First they are plated in 100 μg poly-D-lysine precoated plates, incubated for 20-45 minutes, rinsed with PBS; Glia and astrocytes were selectively attached to the culture dish and neurons were rinsed off. Rinse buffer was plated in a culture dish coated with 500 μg poly-D-lysine, in which case neurons were attached to the culture dish.

16.1.4. Inoculation of Astrocytes in 3D Endothelial Cell Culture

Remove the medium from the mesh, inoculate the astrocytes into the mesh and incubate for 1 hour at 37 ° C. with 5% CO under a humidified atmosphere to 5 × 10 on a mesh coated with confluent endothelial cells (described above). Astrocytes were inoculated. DMEM-K12 containing interferon, transferrin, and selenium is injected into the mesh, followed by successive 2-3 days intervals.

16.1.5. Sowing of Neurons in Three-dimensional Endothelial Cell-astrocytic Tissue Culture

After approximately 5 days the neurons were seeded into endothelial cell-space cell tissue cultures. Neuronal cell cultures showing axon byproducts (observed after about 1 week in culture) were harvested and approximately 5 × 10 Cells were seeded into endothelial / space cell three-dimensional culture mesh. The neuronal cells are seeded in a minimal volume of culture medium and then incubated for 3 hours at 37 ° C. with 5% CO in a wet atmosphere, followed by infusion of standard volume of DMEM / F12, cultured, followed by 2-3 days apart Injected into.

16.2. Results and commitment

The nylon mesh was pre-coated with fetal serum and seeded onto small vascular endothelial cells grown to join standard monolayer cultures and grown to complete confluence.

Neurons and astrocytes were prepared from the cerebellum of fetal mice and separated by differential adsorption. Astrocytes were grown on the combined endothelial three-dimensional matrix matrix and subsequently neuronal cells were added to the three-dimensional tissue culture.

The resulting endothelial cells / astrocytes / neurons three-dimensional tissue cells were maintained until a second, semiconjoined step covering the layer of endothelial cells was reached. As shown in FIG. 15, one layer consists of confluent small vascular endothelial cells and the other layer consists of astrocytes and neurons regenerating the structure of the vascular-brain barrier found in vivo. In this case, substances in the blood penetrate the endothelium of small blood vessels to reach neuronal tissues of the brain. Such a vascular-brain barrier model system can be used to study the passage of compounds or viruses into the brain or their deficiency; This is beneficial for determining which antibiotics such as antivirus can cross the vascular-brain barrier to treat central nervous system infections. Moreover, this model system can be used as a substance to study the activity and potential of various neurotoxicities.

17. Example: 3D Adenocarcinoma Tissue Culture System

17.1. Materials and methods

17.1.1. Preparation of adenocarcinoma stroma and parenchymal cells

Tumor cells were compacted in HBSS, cells were incubated for 24 hours at 37 ° C. in 0.27% trypsin, and cells suspended in DMEM complete medium for 12 hours at 37 ° C. in a plastic dish were further cultured from stromal cells. Separated. The stromal cells are optionally attached to a plastic dish.

17.1.2. Preparation of 3D Substrate Matrix

Three-dimensional matrixes used for adenocarcinoma tissue culture were obtained from tumors (see section 17.1.1. Above) and nylon filtration screens (# 3-210 /) as described for three-dimensional liver culture in Section 13.1.4. 36, Tetko, Inc., NY) is made using 8 mm x 45 mm pieces.

17.1.3. Maintenance of three-dimensional adenocarcinoma tissue culture

After inoculation of the adenocarcinoma cells into the three-dimensional tumor matrix matrix, the cultures were kept in 5% CO at 37 ° C humidification in DMEM medium with high glucose, 15% FBS and 0.03% glutamine and fresh medium every three days. Injected.

17.2. Results and discussion

16 is a micrograph of a three-dimensional adenocarcinoma tissue culture. Adenocarcinoma cells exhibited three-dimensional tumor-like structures with overlapping and arranged characteristics. The cells retained these epithelial-like shapes.

18. Example 3D Tissue Culture Cytotoxicity Test System

18.1. Materials and methods

18.1.1. Preparation of 3D Bone Marrow Tissue Culture

Three-dimensional bone marrow tissue culture was prepared according to the method described in section 11 above.

18.1.2. Exposure to Cytotoxic Agents in Three-Dimensional Bone Marrow Cultures

Individual three-dimensional bone marrow cultures were maintained in 96 well tissue-culture wells for cytotoxicity testing purposes.

Cultures were exposed for 24 hours to 10-fold dilutions of adriamycin in the 0.1-10 μm range. Criteria were exposed to 10-fold dilutions of bovine serum albumin (BSA).

Similarly, other three-dimensional bone marrow cultures in 96-well multi-well tissue culture units were exposed to 10-fold dilutions of cis-platinum in the 1-75 μm range for 24 hours. Criteria were exposed to BSA serial dilutions.

In all cases a monolayer of human fibroblasts cultured by conventional techniques was compared to a three-dimensional culture with stromal cells only or hematopoietic cells.

18.1.3. Cytotoxicity Test

The medium was removed from the cells and 0.2 ml neutral-red dye-mediated solution (see section 18.1.4. Below) was added to each well. The cultures were then incubated for 3 hours at 37 ° C. Well 1A was used as a reference in culture trays containing three-dimensional cultures, which contained only mesh without cells.

After incubation, the dye / medium is removed, and each well is quickly washed with formal-calcium (see section 18.1.4. Below) to remove unbound neutral-red and adhesion of cells to the underlying substrate. Increased.

A 0.2 ml acetic acid / ethanol solution (see section 18.1.4. Below) was added to each well, and the culture was kept at room temperature for 15 minutes (dye extraction) and stirred for several seconds on a shake plate.

The culture tray was transferred to a Dynatech microplate reader equipped with a 540 nm filter for automated spectroscopic reading and recording. Reference wells are based on acetic acid / ethanol solution.

18.1.4. Cytotoxicity Test Solution

Neutral red / medium was prepared as follows. Neutral-Red was prepared in 0.4% aqueous solution and blocked with light using foil. A new 1:80 dye dilution was made. Immediately before use, the dye medium solution was centrifuged at 1500 g for 5 minutes and the supernatant was used for the neutral red assay.

Formal-calcium was prepared as follows. 5 g of CaCl (anhydride) was added to 497.5 ml sterile fed HO and 2.5 ml 40% formaldehyde was added to prepare a formal-calcium solution of 1% CaCl and 0.5% formalin.

An ethanol acetate solution was prepared as follows. 1.09 ml glacial acetic acid was added to 99 ml 50% ethanol.

Adriamycin and cis-platinum are described in Sigma Chemical Co., St. It was purchased from Louis, MO.

18.2. Results and discussion

17 and 18 show the results of a three-dimensional bone marrow culture cytotoxicity test using adriamycin and cis-platinum respectively. In each case, the three-dimensional culture system showed a dose-related response to the test agent. Importantly, either Adriamycin or cis-platinum, the TD for myeloid three-dimensional cultures differed from the TD measured using conventional fibroblast monolayer cultures. Importantly, these results may not be a precise measure of the cytotoxicity of monolayer cultures, which may possibly result in cells growing in an extremely unnatural environment, and monolayer cell cultures being more sensitive to toxic agents. It is difficult to measure the actual toxicity of the test substance; For example, it may be important to administer the highest dose that can be tolerated to remove malignant cells from chemotherapy. The maximum dose may be underestimated so that the anticancer agent is administered in an amount less effective. In addition to providing bone marrow and other normal tissues as well as three-dimensional tissue cultures of tumor tissues, the present invention enables the determination of optimal doses of chemotherapeutic agents in vitro.

19. Example: Three-dimensional skin culture system for transplantation using renal skin in a pig

Skin transplantation was performed on four Charles River micropig. The experiments were aimed at comparing the effect of epithelialization and treatment of the split-thickness and whole-thickness upper body on renal skin, mesh substrates permeated with cell eluate, and contraction. A number of side-by-side wounds were compared along the dorsal surface of each animal to ensure a precise assessment of the treatment at each site. In this study the biodegradable mesh was inoculated with porcine skin fibroblasts and implanted as a skin substitute. Other meshes included human skin fibroblasts and porcine skin fibroblasts were inoculated with porcine keratinocytes. By monitoring the total changes in the implanted area and shape (exudates, erythema, etc.) through histological sections, the efficacy of the three-dimensional skin system as a transplant model could be studied.

19.1. Materials and methods

19.1.1. Preparation of a Wounded Bed

In order to properly assess epithelial grafts, it is essential to make a graft bed so that there are no lines of dermis, hair vesicles, sweat or sebum left. To accomplish this, the thickest skin was removed from the upper side of the pig using Browne skin nodes at settings of 0.075-0.090 inches. 5cm × 5cm wounds were made. The setting was adjusted to 0.60-0.75 inches when the lower side region was made. The mesh alone or with the cultured cells was placed directly above the fascia on the bed. Sterile skin-prepared beds reduced the likelihood of contamination, allowing absolute hemostasis in the transplant bed.

If there was some bleeding after skin removal, the dry gauze dressing was placed on the wound and pressured for 10-15 minutes. In all cases the sterile bed was covered with sterile gauze pre-soaked with PBS until the implant was placed in the fascia. Press the compression stent into place by placing the silk sutures 3-0 approximately 1 to 1/2 inches apart on each side of the implant bed. The cultured implants (mesh with cells) were removed from the tissue culture flasks with sterile forceps and sutured in place using conventional subcutaneous needle moxa. The implant is covered with waselline gauze and tightened with silk thread to provide a compression stent. This pig is bandaged with an elastic platter. Wound dressings changed after 4 days.

19.1.2. anesthesia

Pigs were anesthetized with ketamine hydrogen chloride (Ketalar) and kept anesthetized with halotan, nitrogen dioxide and oxygen. The skin surface was washed with povidone-iodine (betadine) and 7% alcohol and four full-thick graft beds were prepared on the side of the pig as described above.

19.1.3. Animal maintenance

After 4 to 5 days the wound dressing was removed and the implanted side was examined for signs of infection and / or bottom and once again with Waselin gauze and covered with an elastic flask. The wound treated side was observed at 4 day intervals with a biopsy. Animals were anesthetized with Ketalar to enable 4 mm biopsy disinfectants using disposable Baker punches and sterilization techniques. Samples were sent for histological evaluation to assess graft attachment and wound care.

19.1.4. Epithelial implants

The selected animals received semi-transplantation of self-recognized keratinocytes 10 days after implantation with skin equivalents. Keratin cell sheets made from isolated cells grown in over-confluence were incubated for 10-14 days prior to transplantation into skin equivalents. The sheet is attached by four topical seals, and the cells are attached by covering it with waseline gauze and a bandage.

19.2. result

In animal treatments, skin equivalents were attached well, preventing contraction and dehydration and providing a bed of living tissue where epithelial cells could migrate or be placed in autologous transplantation. 19 is representative of treatment 10 days after transplanting human skin equivalents (new skin) into the wound of full thickness. They show the use of allogeneic fibroblasts for transplantation, with minimal contraction but no rejection. This aspect showed histological evaluation of fibroblasts' active growth and deposition of collagen with minimal white cell infiltration (FIG. 20). Branch thickness wounds showed significant differences in growth, epithelialization, pigmentation and hair growth as compared to wounds treated with skin equivalents (left) and biodegradable mesh alone (right) (FIG. 21). The mesh impregnated with fibroblast lysates showed an increase in epithelial growth above the mesh fibrotic area (FIG. 22) but a slower overall treatment than the treatment with live renal skin.

Renal skin increased epithelial migration to the therapeutic side. As shown in FIG. 23, keratinocytes formed deep rete peg when migrated to and attached to the raw dermis equivalent. This form is characteristic of epithelialization at the healing site.

Autologous keratinocytes adhere well and are even cured on new skin. Figure 24 shows a comparison of wound treatment, of which half received autologous epithelial transplantation and the other half received only new skin. Epithelial transplantation was treated uniformly, further shrinkage was prevented and firmly attached to the underlying skin equivalent. 25 shows uniform growth and adhesion of skin cells to new skin. The new skin appeared to be composed of actively growing fibroblasts and naturally-secreted fibroblasts. Mesh fibers were still present as seen in the cross-section.

19.3. discussion

To date, transplantation experiments have shown that new skin (naturally secreted collagen from fibroblasts and biodegradable meshes) provided excellent treatment for full-thick wounds. The ability to use allogeneic renal skin in burn victims and patients with pressure sores using heterogeneous implants has been described. The transplant allows for the support and growth of autologous epithelial sheets as well as migration of epithelial cells to the transplanted surface. The implants were permanent after 4 months with no signs of overlap or deep scars.

Claims (19)

A method of testing the effectiveness of a drug, comprising: (a) exposing the drug to a three-dimensional cell culture, wherein the three-dimensional cell culture consists of parenchymal cells grown in living stromal tissue made in vitro and is alive. The stromal tissue is a connective tissue protein naturally secreted by the stromal and stromal cells that attach to and surround a structure composed of a biocompatible non-living substance with interstitial spaces connected by the stromal cells. Consisting of; And (b) determining the effect of the drug on the cells in the three-dimensional cell culture. The method of claim 1, wherein the stromal cells comprise fibroblasts. The method of claim 1, wherein the stromal cells are endothelial cells, perivascular cells, macrophages, unicellular cells, leukocytes, plasma cells, mast cells or adipocytes and fibroblasts. The method of claim 1, wherein the construct is comprised of a biodegradable material. The method of claim 4, wherein the biodegradable material is selected from cotton, polyglycolic acid, cat intestinal suture, cellulose, gelatin or dextran. The method of claim 1, wherein the construct is comprised of a material that is not biodegradable. 7. The non-biodegradable material according to claim 6, characterized in that it is selected from polyamides, polyesters, polystyrenes, polypropylenes, polyacrylates, polyvinyls, polycarbonates, polytetrapuloethylene or nitrocellulose compounds. How to test drug effects. 8. The method of any one of claims 4,5,6 or 7, wherein the construct is precoated with collagen. The method of claim 1, wherein the structure is a mesh. The method of claim 8, wherein the structure is a mesh. The method of claim 1, wherein the parenchymal cells comprise hematopoietic cells. The method of claim 1, wherein the parenchymal cells comprise black blood cells and keratinocytes. The method of claim 1, wherein the parenchymal cells comprise liver cells. The method of claim 1, wherein the parenchymal cells comprise pancreatic progenitor cells. The method of claim 1, wherein the parenchymal cells comprise mucosal epithelial cells. The method of claim 1, wherein the parenchymal cells comprise virus-infected mucosal epithelial cells. The method of claim 1, wherein the parenchymal cells comprise mucosal epithelial cells infected with a herpesvirus. The method of claim 1, wherein the parenchymal cells comprise mucosal epithelial cells infected with papillomavirus. The method of claim 1, wherein the parenchymal cells comprise tumor cells.