WO2022076519A1 - Procédés et systèmes de récolte et de réensemencement de culture cellulaire utilisant des substrats solubles - Google Patents

Procédés et systèmes de récolte et de réensemencement de culture cellulaire utilisant des substrats solubles Download PDF

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WO2022076519A1
WO2022076519A1 PCT/US2021/053711 US2021053711W WO2022076519A1 WO 2022076519 A1 WO2022076519 A1 WO 2022076519A1 US 2021053711 W US2021053711 W US 2021053711W WO 2022076519 A1 WO2022076519 A1 WO 2022076519A1
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cells
cell culture
dissolvable
scaffold
foam
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PCT/US2021/053711
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English (en)
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Martial Hervy
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Corning Incorporated
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    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M25/00—Means for supporting, enclosing or fixing the microorganisms, e.g. immunocoatings
    • C12M25/14—Scaffolds; Matrices
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M47/00—Means for after-treatment of the produced biomass or of the fermentation or metabolic products, e.g. storage of biomass
    • C12M47/02—Separating microorganisms from the culture medium; Concentration of biomass
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N5/00—Undifferentiated human, animal or plant cells, e.g. cell lines; Tissues; Cultivation or maintenance thereof; Culture media therefor
    • C12N5/0068—General culture methods using substrates
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N2513/00—3D culture
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N2533/00—Supports or coatings for cell culture, characterised by material
    • C12N2533/30—Synthetic polymers
    • C12N2533/40—Polyhydroxyacids, e.g. polymers of glycolic or lactic acid (PGA, PLA, PLGA); Bioresorbable polymers
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N2537/00—Supports and/or coatings for cell culture characterised by physical or chemical treatment
    • C12N2537/10—Cross-linking

Definitions

  • the present disclosure generally relates to dissolvable cell culture materials and methods of using them.
  • the present disclosure relates to dissolvable foam scaffolds for cell culture and methods of making and using such dissolvable foam scaffolds, including methods of using them to expand cell cultures using harvesting and reseeding methods.
  • 3D cell culture in contrast to 2D culture, more accurately represents the environment experienced by cells in-vivo, and it has been demonstrated that cell responses in 3D cultures are more similar to in-vivo behavior than the cell responses in 2D cultures.
  • the additional dimensionality of 3D cultures is believed to lead to the differences in cellular responses because not only does it influence the spatial organization of the cell surface receptors engaged in interactions with surrounding cells, but it also induces physical constraints to cells. These spatial and physical aspects in 3D cultures are believed to affect the signal transduction from the outside to the inside of cells, and ultimately influence gene expression and cellular behavior.
  • 3D culture technologies which simulate the natural 3D environment of cells.
  • Some bioreactors include a carrier in the form of a stationary packing material forming a fixed or packed bed for promoting cell adhesion and growth.
  • the arrangement of the packing material of the fixed bed affects local fluid, heat, and mass transport, and usually is very dense to maximize cell cultivation in a given space.
  • Yet another 3D cell culture technology is a porous 3D matrix or scaffold which promotes the growth and proliferation of the cultured cells within pores and other interior spaces of the matrix.
  • a protease treatment may be used to harvest the cells.
  • commonly used harvesting procedures such as protease treatment, subject the cells to harsh conditions which may damage cell structure and function.
  • protease treatment alone often causes only a limited amount of cell detachment.
  • the problem results from the densely packed nature of the fixed bed material which makes it more difficult to circulate the protease agent throughout the bed and increase the yield of cells harvested.
  • it can be difficult to circulate the protease agent through interior spaces of the 3D matrix, which in turn makes it difficult to dislodge cells during the harvest process. This difficulty is compounded by the presence of extracellular macromolecules secreted by the cultured cells that serve to attach the cells to the surface of the fixed bed material or to the surface of the matrix.
  • Existing packed bed substrates are generally made from unwoven plastic fibers or mats offering surface to volume ratios that are large compared to 2D surfaces.
  • a down-side to these substrates is the difficulty or impossibility to efficiently harvest intact and/or viable cells from them, as described above.
  • a number of cells in relation with the available surface must be introduced in the setup. For large surface areas, the number of cells required to do so cannot be banked and an amplification of a cell population from the vial stored in the working cell bank is required.
  • a method of cell seed train expansion includes providing a first cell culture substrate of a dissolvable foam scaffold, and delivering cells and a cell culture media to the first cell culture substrate, the cells being seeded on or in the dissolvable foam scaffold of the first cell culture substrate.
  • the method further includes controlling environmental conditions and composition of the cell culture media to promote culturing of the cells on the first cell culture substrate, and then dissolving the dissolvable foam scaffold of the first cell culture substrate to form a solution containing the cells.
  • the method further includes harvesting the cells from the solution, and reseeding at least a portion of the cells that were harvested onto a second cell culture substrate of the dissolvable foam scaffold, wherein the dissolvable foam scaffold of the first cell culture substrate is the same material as the dissolvable foam scaffold of the second cell culture substrate.
  • the method can include delivering cell culture media to the second cell culture substrate; and controlling environmental conditions and composition of the cell culture media to promote culturing of the cells in the dissolvable foam scaffold of the second cell culture substrate.
  • the dissolvable foam scaffold of the second cell culture substrate can be dissolved and cell harvested therefrom.
  • the method can further include reseeding at least a portion of the cells that were harvested from the second cell culture substrate onto a third cell culture substrate of the dissolvable foam scaffold, wherein the dissolvable foam scaffold of the third cell culture substrate is the same material as the dissolvable foam scaffold of the second cell culture substrate.
  • the cells are seeded on the first cell culture substrate such that the cells enter pores of the dissolvable foam scaffold.
  • the dissolvable foam scaffold can be disposed in a container configured to hold the cell culture media.
  • the container can be a perfusion bioreactor.
  • a volume of the second cell culture substrate is greater than a volume of the first cell culture substrate. Further, a volume of the third cell culture substrate is greater than the volume of the second cell culture substrate.
  • the dissolvable foam scaffold includes an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; and at least one first water-soluble polymer having surface activity.
  • a method of cell seed train expansion for scaling a cell sample to a production scale reactor includes expanding the cell sample containing cells on a first dissolvable foam scaffold; expanding at least a portion of the cells harvested from the first dissolvable foam scaffold onto a second dissolvable foam scaffold; and seeding at least a portion of the cells harvested from at least one of the first dissolvable foam scaffold and the second dissolvable foam scaffold onto a third dissolvable foam scaffold.
  • the first, second, and third dissolvable foam scaffold comprise the same scaffold material.
  • Figure 1 is an illustration of a seed train method for the seeding of a production-scale reactor using 2D surfaces for the production of the cell mass needed to seed a production reactor.
  • Figure 2 is an illustration of a seed train method for the seeding of a production-scale reactor using increasing volumes of dissolvable scaffolds for the production of the cell mass needed to seed a production reactor, according to embodiments of this disclosure.
  • Figure 3 is a perspective view of a dissolvable foam scaffold in accordance with the present disclosure.
  • Figure 4 shows an SEM picture of a foam scaffold prepared in Example 1.
  • Figure 5 shows an SEM picture of a foam scaffold prepared in Example 2.
  • Figure 6 shows an SEM picture of a foam scaffold prepared in Example 3.
  • Figure 7 shows an SEM picture of a foam scaffold prepared in Example 4.
  • Figure 8 shows an SEM picture of a foam scaffold prepared in Example 5.
  • Figure 9 shows an SEM picture of a foam scaffold prepared in Example 6.
  • Figure 10 shows an SEM picture of a foam scaffold prepared in Example 7.
  • Figure 11 shows an SEM picture of a foam scaffold prepared in Example 8.
  • Figure 12 shows an SEM picture of a foam scaffold prepared in Example 9.
  • Figure 13 shows an SEM picture of a foam scaffold prepared in Example 10.
  • Figure 14 shows an SEM picture of a foam scaffold prepared in Example 11.
  • Figure 15 shows four foams prepared in Example 12 where varied amounts of a plasticizer were added to form the four foam scaffolds.
  • Figure 16 shows an SEM picture of a foam scaffold prepared in Example 13.
  • Figure 17 shows spheroids formed in the pores of a foam scaffold prepared in Example 4.
  • Figure 18 shows cells adhered to the foam scaffold prepared in Example 14.
  • Figure 19 shows cells adhered to the foam scaffold prepared in Example 15.
  • Figure 20 shows cells after six days of expansion adhered to the foam scaffold prepared in Example 15.
  • Figure 21 is a bar graph showing the GFP-positive percentage of transfected HEK cells for each of the culture conditions of Example 24.
  • Figure 22 is a bar graph showing GFP-positive percentage of transfected cells per set of foam scaffold of Example 25.
  • Figure 23 is a bar graph showing the number of viral particles (vp) per set of foam scaffold of Example 25.
  • Figure 24 is a bar graph showing the number of viral particles per cell obtained per set of foam scaffold of Example 25.
  • Figure 25 is a bar graph showing the fraction of cells exhibiting GFP expression for each of the sets of foam scaffolds of Example 25 after infection.
  • Figure 26 is an illustration of an experimental design to investigate the impact of previous cell culture conditions on cell growth performance, transfection efficiency, and viral vector production performance.
  • Figure 27 is a bar graph showing cell growth performance on CellBIND® surface of cells previously grown for one (pl) or two (p2) passages in PGA scaffolds compared to cells previously grown on CellBIND® (2D).
  • Figure 28 is a bar graph showing cell growth performance in dissolvable PGA scaffolds of cells previously grown for one (pl) or two (p2) passages in PGA scaffolds compared to cells previously grown on CellBIND® (2D).
  • Figure 29 shows fluorescence microscopy images of GFP expression for cells from the different origins (2D, pl and p2) transfected in 2D conditions (upper lane) or in dissolvable scaffolds (lower lane) 3 days after transfection.
  • Figure 30 is a bar graph showing GFP expression of pl and p2 cells at harvest time, after transfection on CellBIND®, reported to GFP expression ratio of cell previously grown in 2D.
  • Figure 31 is a bar graph showing GFP expression of pl and p2 cells at harvest time after transfection in dissolvable scaffolds, reported to GFP expression ratio of cell previously grown in 2D.
  • Figure 32 is a bar graph showing viral particle/cell production on CellBIND® of pl and p2 cells compared to the VP/cell production of 2D cells.
  • Figure 33 is a bar graph showing viral particle/cell production in dissolvable scaffolds of pl and p2 cells compared to the VP/cell production of 2D cells.
  • Figure 34 is a graph of cell number over days during a seed train method according to embodiments of this disclosure.
  • Figure 35 is a graph of the fold expansion of cells from the seed train of Figure 34.
  • embodiments of the present disclosure use a dissolvable scaffold as a substrate for the packed bed. Using this substrate, it is possible to quickly and easily harvest the totality of the cell population with a minimum stress for the cells and without having to use protease.
  • Cells from a working cell bank can then be expanded in initial steps in increasing volumes of dissolvable scaffolds until the adequate number of cells required to seed the final reactor is reached.
  • This method allows an important scale up of the cell culture with a minimal impact on the cells and avoids the above-discussed stress to cell populations that occurs when the seed train transitions an expanded cell culture from one type of surface to another (i.e., inefficiencies from cells from one surface having to adapt to a new, different type of surface).
  • seed train refers to the practice of running cells through multiple cultivation cycles and/or system to grow the cell population with each passage.
  • the purpose of a seed train is the generation of an adequate number of cells for the inoculation of a production bioreactor.
  • the production bioreactor is inoculated out of the largest seed train scale.
  • the seed train steps have a significant impact on the product titer and cell growth in production scale, as well as the success and reproducibility of the seed train itself.
  • One or more embodiments of this disclosure relate to methods that produce a cell population sufficient to seed a packed bed production-scale bioreactor, where the packed bed is composed of a dissolvable 3D substrate material.
  • the packed bed can be, for example, a foam or a fiber mat.
  • the dissolvable foam scaffolds as described herein include at least one ionotropically crosslinked polysaccharide.
  • polysaccharides possess attributes beneficial to cell culture applications.
  • Polysaccharides are hydrophillic, non-cytotoxic and stable in culture medium. Examples include pectic acid, also known as polygalacturonic acid (PGA), or salts thereof, partly esterified pectic acid or salts thereof, or partly amidated pectic acid or salts thereof.
  • Pectic acid can be formed via hydrolysis of certain pectin esters.
  • Pectins are cell wall polysaccharides and in nature have a structural role in plants.
  • Major sources of pectin include citrus peel (e.g., peels from lemons and limes) and apple peel.
  • Pectins are predominantly linear polymers based on a 1,4-linked alpha-D-galacturonate backbone, interrupted randomly by 1,2-linked L-rhamnose. The average molecular weight ranges from about 50,000 to about 200,000 Daltons.
  • the dissolvable scaffolds can be made with or without functionalization (e.g., grafting/coating) of alginate, of starch, or of foamy protein dissolvable by an enzyme.
  • functionalization e.g., grafting/coating
  • cells are initially expanded on 2D surface until the needed number of cells is reached, and cells are then harvested using proteases and the desirable number of cells is seeded in the packed bed material.
  • cells are seeded in a small volume of the dissolvable scaffold, which is used as a packed-bed material in a bioreactor and expanded for a given time.
  • the scaffold is then dissolved, and the cells released are harvested and reseeded in an increased volume of the same dissolvable material until the desirable cell number required to seed the production-scale reactor is reached.
  • a dissolvable scaffold can be used in both the seed train and the production scale reactor, methods of this disclosure can include a production reactor with a different type of cell culture substrate.
  • the methods of this disclosure having significant advantages over existing seed train and scale up methods.
  • the cells used in methods of the present disclosure do not need to adapt to a new substrate surface — the so-called problem of adaptation. That is, traditionally, if a cell population is started on a 2D surface at the initial stage(s) of the seed train, when the expanded population is passed to a 3D substrate or another type of substrate surface that differs from the 2D surface of the initial stage(s), the cell culture will experience some type of inefficiency (e.g., a slow down in cell growth and expansion, or a negative impact on viral vector production). As will be discussed below, methods of this disclosure can overcome this adaptation problem, including avoiding the decrease in viral vector production. These advantages can increase efficiency by minimizing lag time and adaptation time after reseeding onto a larger volume substrate.
  • advantages include reductions in footprints for the cell culture components or systems to produce the desired numbers of cells for production-scale reactor seeding.
  • the 3D scaffold can produce more cells per area of reactor footprint compared to a 2D surface.
  • the 3D scaffolds can be used in fewer vessels — even a single vessel — and thus can reduce labor requirements and risk of contamination.
  • the dissolvable scaffolds of this disclosure can allow harvesting cells without protease, if desired, and without mechanical agitation. Eliminating these conditions from cell harvesting can improve the quality and viability of harvested cells, and may also improve the yield of harvested cells. For example, according to embodiments of this disclosure, 100% of cells may be harvested, compared to 90% or less of cells when using protease (e.g., trypsin) and/or vibration.
  • protease e.g., trypsin
  • Figures 1 and 2 represent a standard seed train process and a seed train according to embodiments of this disclosure, respectively.
  • Figure 1 after cells are thawed from a cell bank, cells are expanded on 2D surfaces at each step 1-3. With each subsequent step, the two-dimensional surface needed increases and quickly results in a large footprint of 2D surface vessels.
  • Table 1 shows the number of 2D flasks (Coming® CellBIND® 225 cm 2 T-Flasks) are needed at steps 1, 2, and 3 of Figure 1.
  • Figure 2 shows a method in which a dissolvable 3D scaffold is used in each of steps 1, 2, and 3.
  • the volumes of scaffold required at steps 1, 2, and 3 are 25 mL, 500 mL, and 10 L, as summarized in Table 1.
  • embodiments of the current disclosure result in significant footprint savings compared to a 2D seed train.
  • the cells may need to be passed from the 2D surface in step 3 to another surface in the production-scale vessel of step 4.
  • this cell passage between different culture surfaces can result in a cell adaptation phase that negatively impacts cell growth and/or viral vector production and efficiency.
  • embodiments of the current disclosure can avoid the negative impacts of cell adaptation by using the same 3D dissolvable scaffold in all of steps 1-4. As discussed below, this results in improved cell culture performance, viral vector production, and other advantages. Further details of the method in Figure 2 are described in the examples below, including Example 27.
  • Embodiments of the present disclosure relate to dissolvable foam scaffolds for cell culture and methods of making such dissolvable foam scaffolds. Embodiments of the present disclosure further relate to methods of cell culture of adherent cells, cell aggregates, or spheroids, in dissolvable foam scaffolds. Furthermore, embodiments of the present disclosure relate to bioreactors systems including dissolvable foam scaffolds. As will become clearer in the discussions below, foam scaffolds as disclosed herein are described as being dissolvable and insoluble. As used herein, the term “insoluble” is used to refer to a material or combination of materials that is not soluble, and that remains crosslinked, under conventional cell culture conditions which include, for example, cell culture media.
  • dissolvable is used to refer to a material or combination of materials that is digested when exposed to an appropriate concentration of an enzyme that digests or breakdowns the material or combination of materials.
  • Dissolvable foam scaffolds as described herein are porous scaffolds having an open pore architecture and highly interconnected pores. The pores of the scaffolds provide a protected environment for the culturing of cells where the cell-to-cell interactions and formation of ECM in a 3D fashion are aided.
  • the dissolvable foam scaffolds may be completely digested which allows for harvesting cells without damaging the cells using protease treatment and/or mechanical harvesting techniques.
  • FIG 3 is a perspective view of a dissolvable foam scaffold 100 in accordance with the present disclosure.
  • dissolvable foam scaffold 100 is a porous foam that includes an open pore architecture.
  • Dissolvable foam scaffold 100 has a porosity of from about 85% to about 96% and an average pore size diameter of between about 50 pm and about 500 pm.
  • Dissolvable foam scaffold 100 provides a protected environment within the pores of the foam scaffold for the culturing of cells. Additionally, dissolvable foam scaffold 100 is also dissolvable when exposed to an appropriate enzyme that digests or breakdowns the material which facilitates harvesting of the cells cultured in the scaffold without damaging the cells.
  • Dissolvable foam scaffolds as described herein include at least one ionotropically crosslinked polysaccharide.
  • polysaccharides possess attributes beneficial to cell culture applications.
  • Polysaccharides are hydrophillic, non-cytotoxic and stable in culture medium. Examples include pectic acid, also known as polygalacturonic acid (PGA), or salts thereof, partly esterified pectic acid or salts thereof, or partly amidated pectic acid or salts thereof.
  • Pectic acid can be formed via hydrolysis of certain pectin esters.
  • Pectins are cell wall polysaccharides and in nature have a structural role in plants. Major sources of pectin include citrus peel (e.g., peels from lemons and limes) and apple peel.
  • Pectins are predominantly linear polymers based on a 1,4-linked alpha-D-galacturonate backbone, interrupted randomly by 1,2-linked L-rhamnose. The average molecular weight ranges from about 50,000 to about 200,000 Dal
  • the polygalacturonic acid chain of pectin may be partly esterified, e.g., methyl groups and the free acid groups may be partly or fully neutralized with monovalent ions such as sodium, potassium, or ammonium ions.
  • Polygalacturonic acids partly esterified with methanol are called pectinic acids, and salts thereof are called pectinates.
  • the degree of methylation (DM) for high methoxyl (HM) pectins can be, for example, from 60 to 75 mol% and those for low methoxyl (LM) pectins can be from 1 to 40 mol%.
  • the degree of esterification of partly esterified polygalacturonic acids as described herein may be less than about 70 mol%, or less than about 60 mol%, or less than 50 mol%, or even less than about 40 mol%, and all values therebetween. Without wishing to be bound by any particular theory, it is believed that a minimum amount of free carboxylic acid groups (not esterified) facilitates a degree of ionotropic crosslinking which allow for the formation of a dissolvable scaffold which is insoluble.
  • the polygalacturonic acid chain of pectin may be partly amidated.
  • Polygalacturonic acids partly ami dated pectin may be produced, for example, by treatment with ammonia. Amidated pectin contains carboxyl groups (-COOH), methyl ester groups (-COOCHs), and amidated groups (-CONH2). The degree of amidation may vary and may be, for example, from about 10% to about 40% amidated.
  • dissolvable foam scaffolds as described herein may include a mixture of pectic acid and partly esterified pectic acid. Blends with compatible polymers may also be used.
  • pectic acid and/or partly esterified pectic acid may be mixed with other polysaccharides such as dextran, substituted cellulose derivatives, alginic acid, starches, glycogen, arabinoxylans, agarose, etc.
  • Glycosaminoglycans like hyaluronic acid and chondroitin sulfate, or various proteins such as elastin, fibrin, silk fibroin, collagen and their derivatives can be also used.
  • Water soluble synthetic polymers can be also blended with pectic acid and/or partly esterified pectic acid.
  • Exemplary water-soluble synthetic polymers include, but are not limited to, polyalkylene glycol, poly(hydroxyalkyl(meth)acrylates), poly(meth)acrylamide and derivatives, poly(N- vinyl-2-pyrrolidone), and polyvinyl alcohol.
  • dissolvable foam scaffolds as described herein may further include at least one first polymer.
  • the at least one first polymer is water soluble, non-ionotropically crosslinkable and has surface activity.
  • surface activity refers to the activity of an agent to lower or eliminate the surface tension (or interfacial tension) between two liquids or between a liquid and a solid or between gas and liquid.
  • the at least one first polymer may have a hydrophilic-lipophilic balance (HLB) of greater than about 8 or even greater than about 10.
  • HLB hydrophilic-lipophilic balance
  • the at least one first polymer may have an HLB of between about 8 and about 40 or between about 10 and about 40.
  • the at least one first polymer may have an HLB of between about 8 and about 15, or even between about 10 and about 12.
  • HLB provides a reference for the lipophilic or hydrophilic degree of a polymer. A larger HLB value indicates stronger hydrophilicity, while a smaller HLB value indicates a stronger lipophilicity.
  • the HLB value varies in the range of from 1 to 40 and the hydrophilic-lipophilic transition is often considered to be between about 8 and about 10. When the HLB value is less than the hydrophilic-lipophilic transition, the material is lipophilic, and when the HLB value is greater than the hydrophilic- lipophilic transition the material is hydrophilic.
  • Exemplary first polymers in accordance with embodiments of the present disclosure may be any of cellulose derivatives, proteins, synthetic amphiphilic polymers, and combinations thereof.
  • Exemplary cellulose derivatives include, but are not limited to, hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), methylcellulose (MC), hydroxyethylmethylcellulose (HEMC), and hydroxypropyl-methylcellulose (HPMC).
  • Exemplary proteins include, but are not limited to, bovine serum albumin (BSA), gelatine, casein and hydrophobins.
  • Exemplary synthetic amphiphilic polymers include, but are not limited to, a poloxamer available under the trade name Synperonics® (commercially available from Croda International, Snaith, United Kingdom), a poloxamer available under the trade name Pluronics® (commercially available from BASF Corp., Parsippany, NJ) and a poloxamer available under the trade name Kolliphor® (commercially available from BASF Corp., Parsippany, NJ).
  • Synperonics® commercially available from Croda International, Snaith, United Kingdom
  • Pluronics® commercially available from BASF Corp., Parsippany, NJ
  • Kolliphor® commercially available from BASF Corp., Parsippany, NJ.
  • Dissolvable foam scaffolds as described herein may further include at least one second polymer.
  • the at least one second polymer is water soluble and has no surface activity.
  • Exemplary second polymers may be any of synthetic polymers, semisynthetic polymers, natural polymers and combinations thereof.
  • Exemplary synthetic polymers include, but are not limited to, polyethylene glycol, polyvinyl pyrrolidone, polyvinyl alcohol, carboxyvinyl polymer, polyacrylic acid, polyacrylamide, homopolymer and copolymer of N- (2 -Hydroxypropyl) methacrylamide, polyvinyl methyl ether-maleic anhydride, and polyethylene oxide/polypropylene oxide block copolymers.
  • Exemplary semisynthetic polymers include, but are not limited to, dextran derivatives, carboxymethyl cellulose, hydroxyethyl cellulose and derivatives, methylcellulose and derivatives, ethylcellulose cellulose, ethyl hydroxyethyl cellulose, and hydroxypropyl cellulose.
  • Exemplary natural polymers include, but are not limited to, starch and starch derivatives, polymers obtained by microbial fermentation such as curdlan, pullulan and gellan gum, xanthan gum, dextran, proteins such as albumin, casein and caseinates, gelatin, seaweed extracts such as agar, alginates and carrageenan, seed extracts such as guar gum and derivatives and locust bean gum, hyaluronic acid, and chondroitin sulfate.
  • Dissolvable foam scaffolds as described herein may be crosslinked to increase their mechanical strength and to prevent the dissolution of the scaffolds when placed in contact with cell culture medium.
  • Crosslinking may be performed by ionotropic gelation as described below wherein ionotropic gelation is based on the ability of poly electrolytes to crosslink in the presence of multivalent counter ions to form crosslinked scaffolds. Without wishing to be bound by any particular theory, it is believed that ionotropic gelation of the polysaccharide of the dissolvable foam scaffolds is the result of strong interactions between divalent cations and the polysaccharide.
  • scaffolds as described herein are porous foam scaffolds.
  • Foam scaffolds as described herein may have a porosity of from about 85% to about 96%.
  • foam scaffolds as described herein may have a porosity of from about 91% to about 95%, or about 94% to about 96%.
  • the term “porosity” refers to the measure of open pore volume in the dissolvable scaffold and is referred to in terms of % porosity, wherein % porosity is the percent of voids in the total volume of the dissolvable foam scaffold.
  • Foam scaffolds as described herein may have an average pore size diameter of between about 50 pm and about 500 pm.
  • average pore size diameter may be between about 75 pm and about 450 pm, or between about 100 pm and about 400 pm, or even between 150 pm and about 350 pm and all values therebetween.
  • Scaffolds as described herein may have a wet density of less than about 0.40 g/cc.
  • scaffolds as described herein may have a wet density of less than about 0.35 g/cc, or less than about 0.30 g/cc, or less than about 0.25 g/cc.
  • Scaffolds as described herein may have a wet density of between about 0.16 g/cc and about 0.40 g/cc, or between about 0.16 g/cc and about 0.35 g/cc, or between about 0.16 g/cc and about 0.30 g/cc, or even between about 0.16 g/cc and about 0.25 g/cc, and all values therebetween.
  • Scaffolds as described herein may have a dry density of less than about 0.20 g/cc.
  • scaffolds as described herein may have a dry density of less than about 0.15 g/cc, or less than about 0.10 g/cc, or less than about 0.05 g/cc.
  • Scaffolds as described herein may have a dry density of between about 0.02 g/cc and about 0.20 g/cc, or between about 0.02 g/cc and about 0.15 g/cc, or between about 0.02 g/cc and about 0.10 g/cc, or even between about 0.02 g/cc and about 0.05 g/cc, and all values therebetween.
  • Open pores allow for cellular access on both sides of the scaffold and allow for liquid flow and transport of nutrients through the dissolvable scaffold.
  • Partially open pores allow for cellular access on one side of the scaffold, but mass transport of nutrients and waste products is limited to diffusion.
  • Closed pores have no openings and are not accessible by cells or by mass transport of nutrients and waste products.
  • Dissolvable foam scaffolds as described herein have an open pore architecture and highly interconnected pores. Generally, the open pore architecture and highly interconnected pores enable migration of cells into the pores of the dissolvable foam scaffolds and also facilitate enhanced mass transport of nutrients, oxygen and waste products.
  • the open pore architecture also influences cell adhesion and cell migration by providing a high surface area for cell-to-cell interactions and space for ECM regeneration.
  • Dissolvable foam scaffolds as described herein are digested when exposed to an appropriate enzyme that digests or breakdowns the material.
  • Non-proteolytic enzymes suitable for digesting the foam scaffolds, harvesting cells, or both include pectinolytic enzymes or pectinases, which are a heterogeneous group of related enzymes that hydrolyze the pectic substances.
  • Pectinases polygalacturonase are enzymes that break down complex pectin molecules to shorter molecules of galacturonic acid.
  • PectinexTM ULTRA SP-L commercially available fromNovozyme North American, Inc., Franklinton, NC
  • PectinexTM ULTRA SP- L contains mainly polygalacturonase, (EC 3.2.1.15) pectintranseliminase (EC 4.2.2.2) and pectinesterase (EC: 3.1.1.11).
  • the EC designation is the Enzyme Commission classification scheme for enzymes based on the chemical reactions the enzymes catalyze.
  • digestion of the dissolvable foam scaffolds also includes exposing the scaffold to a divalent cation chelating agent.
  • exemplary chelating agents include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic (CDTA), ethylene glycol tetraacetic acid (EGTA), citric acid and tartaric acid.
  • the time to complete digestion of dissolvable foam scaffolds as described herein may be less than about 1 hour.
  • the time to complete digestion of foam scaffolds may be less than about 45 minutes, or less than about 30 minutes, or less than about 15 minutes, or between about 1 minute and about 25 minutes, or between about 3 minutes and about 20 minutes, or even between about 5 minutes and about 15 minutes.
  • scaffolds as described herein may further include an adhesion polymer coating.
  • the adhesion polymer may include peptides.
  • Exemplary peptides may include, but are not limited to BSP, vitronectin, fibronectin, laminin, Type I and IV collagen, denatured collagen (gelatin), and like peptides, and mixtures thereof. Additionally, the peptides may be those having an RGD sequence.
  • the coating may be, for example, Synthemax® II-SC (commercially available from Coming, Incorporated, Coming, NY).
  • the adhesion polymer may include an extracellular matrix.
  • the coating may be, for example, Matrigel® (commercially available from Coming, Incorporated, Coming, NY).
  • Methods as described herein may include forming a first aqueous mixture which includes dissolving a polysaccharide in an aqueous solution.
  • Polysaccharides may be those as described above, such as pectic acid or salts thereof, partly esterified pectic acid or salts thereof, or partly amidated pectic acid or salts thereof, and blends of such polysaccharides.
  • Methods for forming dissolvable foam scaffolds as described herein may further include forming a second aqueous mixture including a water insoluble divalent metal salt in an aqueous solution.
  • Metals of the divalent metal salts may include, but are not limited to, magnesium, calcium, zinc, strontium, barium, and like cations, and combinations thereof.
  • Anions of the divalent metal salts may include, but are not limited to, oxalates, tartrates, phosphates, carbonates, citrates, and like organic and inorganic anions, and combinations thereof.
  • forming a second aqueous mixture may further include adding the at least one first polymer as described above to the second aqueous mixture.
  • methods as described herein may further include adding the at least one second polymer as described above to the second aqueous mixture.
  • the at least one first polymer and the at least one second polymer may be added to the second aqueous mixture separately or may be added to the second aqueous mixture together.
  • the mixture may include about 50% of the at least one first polymer and about 50% of the at least one second polymer.
  • the mixture may include between about 35% and about 65% (and all values therebetween) of the at least one first polymer and between about 35% and about 65% (and all values therebetween) of the at least one second polymer.
  • forming a second aqueous mixture may further include adding a water-soluble plasticizer to the second aqueous mixture.
  • Plasticizers as described herein are non-toxic and do not affect the solubility of the polysaccharides of the dissolvable foam scaffolds.
  • a plasticizer provides flexibility and softness to the resulting foam such that the resulting foam is soft and pliable.
  • Plasticizers as described herein may include, but are not limited to, polyhydric alcohols such as glycerol, sorbitol, ethylene glycol, propylene glycol, polyethylene glycol and combinations thereof.
  • Adding a water soluble plasticizer to the second aqueous mixture may include adding less than about 55 wt.
  • adding a water soluble plasticizer to the second aqueous mixture may include adding less than about 50 wt. %, or less than about 40 wt. %, or less than about 30 wt. %, or less than about 25 wt. %, or between about 15 wt. % and about 55 wt. % ,or between about 15 wt. % and about 50 wt. %, or between about 15 wt. % and about 40 wt. %, or between about 15 wt. % and about 30 wt. %, or between about 15 wt. % and about 25 wt.
  • total solid additives added to form the second aqueous mixture refers to all of the components of the aqueous mixture except for water.
  • forming a second aqueous mixture may further include adding an emulsifying agent to the second aqueous mixture.
  • Emulsifying agents as described herein may include, but are not limited to, Tween® 20, Tween® 80 (each commercially available from commercially available from Croda International, Snaith, United Kingdom).
  • forming a second aqueous mixture may further include adding at least one leachable solid to the second aqueous mixture.
  • Leachable solids as described herein include materials that reinforce or create pores during the formation of the foam scaffold.
  • Leachable solids may be, but are not limited to, nontoxic leachable materials such as salts, biocompatible mono and disaccharides and water-soluble proteins.
  • Exemplary salts include, but are not limited to, sodium chloride, potassium chloride, calcium chloride, sodium tartrate, sodium citrate, and the like.
  • Exemplary biocompatible mono and disaccharides include, but are not limited to, glucose, fructose, dextrose, maltose, lactose and sucrose.
  • Exemplary water-soluble proteins include, but are not limited to, gelatin and agarose.
  • each of the materials described above in relation to the second aqueous mixture may all be optionally added to the second aqueous mixture and may be added to the second aqueous mixture in any order with the possibility that two or more of the materials may be added to the second aqueous mixture simultaneously.
  • forming a second aqueous mixture includes adding a leachable solid to an aqueous solution including a divalent metal salt and mixing the aqueous mixture to facilitate the dissolution of the leachable solid dissolves in the aqueous mixture.
  • the at least one first polymer, the at least one second polymer and/or the water-soluble plasticizer are subsequently added to the second aqueous mixture.
  • Methods for forming a dissolvable foam scaffold as described herein may further include, subsequent to forming the first and second aqueous mixtures, combining the second aqueous mixture with the first aqueous mixture to form a combined aqueous mixture.
  • a foam may be formed from the combined aqueous mixture by introducing gas bubbles into the aqueous mixture through mixing, beating, agitating, aerating, whipping, injecting or other mechanical actions.
  • the gas may be for example, but not limited to, air, nitrogen, helium, hydrogen, argon, carbon dioxide or other inert gas.
  • the method for forming a dissolvable foam scaffold may further include adding a gel inducing agent to the combined aqueous mixture.
  • the gel inducing agent may be an acid that provides a buffering action and/or materials that slowly generate acid.
  • Exemplary acids include, but are not limited to, lactic acid lactone, glycolic acid lactone, glucono delta lactone and acid anhydrides.
  • Methods for forming a dissolvable foam scaffold as described herein may further include, coating the dissolvable foam scaffold with an adhesion polymer coating.
  • Coating the dissolvable foam scaffold may include exposing the scaffold to an aqueous solution having an adhesion polymer in the aqueous solution.
  • the adhesion polymer may include peptides.
  • Exemplary peptides may include, but are not limited to BSP, vitronectin, fibronectin, laminin, Type I and IV collagen, denatured collagen (gelatin), and like peptides, and mixtures thereof. Additionally, the peptides may be those having an RGD sequence.
  • the coating may be, for example, Synthemax® II-SC (commercially available from Coming, Incorporated, Coming, NY).
  • any type of cell may be cultured on the dissolvable foam scaffolds including, but not limited to, immortalized cells, primary culture cells, cancer cells, stem cells (e.g., embryonic or induced pluripotent), etc.
  • the cells may be mammalian cells, avian cells, piscine cells, etc.
  • the cells may be of any tissue type including, but not limited to, kidney, fibroblast, breast, skin, brain, ovary, lung, bone, nerve, muscle, cardiac, colorectal, pancreas, immune (e.g., B cell), blood, etc.
  • the cells may be in any cultured form in the bag including disperse (e.g., freshly seeded), confluent, 2- dimensional, 3 -dimensional, spheroid, etc.
  • Culturing cells on a dissolvable foam scaffold may include seeding cells on the dissolvable foam scaffold. Seeding cells on a dissolvable foam scaffold may include contacting the scaffold with a solution containing the cells. During seeding cells on the dissolvable foam scaffold, the cells enter the pores of the dissolvable foam scaffold. Where the dissolvable foam scaffold includes an adhesion polymer coating, cells may enter the pores of the dissolvable foam scaffold and attach to the scaffold material.
  • Culturing cells on dissolvable foam scaffolds may further include contacting the scaffolds with cell culture medium.
  • contacting the scaffolds with cell culture medium includes placing cells to be cultured on the scaffolds in an environment with medium in which the cells are to be cultured.
  • Contacting the scaffolds with cell culture medium may include pipetting cell culture medium onto the scaffolds, or submerging the scaffolds in cell culture medium, or passing cell culture media over the scaffolds in a continuous manner.
  • continuous refers to culturing cells with a consistent flow of cell culture medium into and out of the cell culture environment.
  • Such passing cell culture media over the scaffolds in a continuous manner may include submerging the scaffolds in cell culture medium for a predetermined period of time, then removing at least some of the cell culture medium after the predetermined period of time and adding fresh cell culture medium such that the volume of cell culture medium in contact with the dissolvable foam scaffold remains substantially constant.
  • Cell culture medium may be removed and replaced according to any predetermined schedule. For example, at least some of the cell culture medium may be removed and replaced every hour, or every 12 hours, or every 24 hours, or every 2 days, or every 3 days, or every 4 days, or every 5 days.
  • Cell culture medium may be for example, but is not limited to, sugars, salts, amino acids, serum (e.g., fetal bovine serum), antibiotics, growth factors, differentiation factors, colorant, or other desired factors.
  • exemplary cell culture medium includes Dulbecco’s Modified Eagle Medium (DMEM), Ham’s F12 Nutrient Mixture, Minimum Essential Media (MEM), RPMI Medium, Iscove's Modified Dulbecco’s Media (IMDM) MesencultTM-XF medium, and the like.
  • Methods for harvesting cells from dissolvable foam scaffolds as described herein may include digesting the dissolvable foam scaffold by exposing the dissolvable foam scaffold to an enzyme.
  • non- proteolytic enzymes suitable for digesting the foam scaffolds, harvesting cells, or both include pectinolytic enzymes or pectinases, which are a heterogeneous group of related enzymes that hydrolyze the pectic substances.
  • PectinexTM ULTRA SP-L commercially available fromNovozyme North American, Inc., Franklinton, NC
  • PectinexTM ULTRA SP-L contains mainly polygalacturonase, (EC 3.2.1.15) pectintranseliminase (EC 4.2.2.2) and pectinesterase (EC: 3.1.1.11).
  • the EC designation is the Enzyme Commission classification scheme for enzymes based on the chemical reactions the enzymes catalyze.
  • Exposing the dissolvable foam scaffold to an enzyme may include exposing the scaffold to enzyme concentrations of between about 1 and about 200 U.
  • the method may include exposing the scaffold to enzyme concentrations of between about 2 U and about 150 U, or between about 5 U and about 100 U, or even between about 10 U and about 75 U, and all values therebetween.
  • Methods for harvesting cells as described herein may further include exposing the material to a chelating agent.
  • exemplary chelating agents include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic (CDTA), ethylene glycol tetraacetic acid (EGTA), citric acid and tartaric acid.
  • Exposing the dissolvable foam scaffold to a chelating agent may include exposing the scaffold to chelating agent concentrations of between about 1 mM and about 200 mM.
  • the method may include exposing the scaffold to chelating agent concentrations of between about 10 mM and about 150 mM, or between about 20 mM and about 100 mM, or even between about 25 mM and about 50 mM, and all values therebetween.
  • Example 1 A first aqueous mixture containing 2.0 wt. % polygalacturonic acid (PGA) was prepared by dissolving about 162 grams of polygalacturonic acid sodium salt in demineralized water in an oil bath set at a temperature of 104°C. The aqueous mixture was cooled to room temperature. A second aqueous mixture was prepared by adding about 1.06 grams of CaCCh to about 24.52 grams of ultrapure water in the bowl of a KitchenAid mixer equipped with a wire loop whip. About 0.125 grams of TWEEN® 20 (commercially available from Sigma- Aldrich, St. Louis, MO) was also added to the bowl of the KitchenAid mixer.
  • PGA polygalacturonic acid
  • sucrose was then added to the mixer bowl and mixed to facilitate dissolution of the sucrose in the second aqueous mixture.
  • About 7.5 grams glycerol, about 1.94 grams Methocel HPMC Culminal 724 and the first aqueous mixture were added to form a combined aqueous mixture in the mixing bowl and mixed at a stir speed (speed 1 of the KitchenAid mixer) for about 5 minutes.
  • the combined aqueous mixture was then whipped at a fast whipping speed (speed 10 of the KitchenAid mixer) for about 20 minutes to introduce air into the combined aqueous mixture.
  • a solution of about 3.77 grams of gluconolactone (GDL) in about 30 mL of water was added to the mixing bowl and whipping was continued for about 1 minute.
  • GDL gluconolactone
  • Example 2 The process as described in Example 1 was repeated except the second aqueous mixture was prepared by adding about 0.53 grams. The resulting foam was observed to be porous with highly interconnected pores.
  • Figure 5 shows an SEM picture of the foam prepared in this Example 2.
  • Example 3 A first aqueous mixture containing 2.0 wt. % polygalacturonic acid (PGA) was prepared by dissolving about 162 grams of polygalacturonic acid sodium salt in demineralized water in an oil bath set at a temperature of 104°C. The aqueous mixture was cooled to room temperature. A second aqueous mixture was prepared by adding about 7.5 grams of glycerol to ultrapure water and heating under a microwave at 800W for about 30 seconds. About 0.97 grams of bovine gelatin was cold-swelled in about 5.8 mL of ultrapure water and then added to the second aqueous mixture and stirred until dissolution was observed.
  • PGA polygalacturonic acid
  • the second aqueous mixture was then sonicated for about 1 minute and then transferred to the bowl of a KitchenAid mixer equipped with a wire loop whip.
  • About 17.5 grams sucrose and about 0.97 grams Methocel HPMC Culminal 724 were then added to the bowl of the KitchenAid mixer and the aqueous mixture was stirred for about 5 minutes.
  • the first aqueous mixture containing 2.0 wt. % PGA were added to form a combined aqueous mixture in the mixing bowl and mixed at a stir speed (speed 1 of the KitchenAid mixer) for about 3 minutes.
  • the combined aqueous mixture was then whipped at a fast whipping speed (speed 10 of the KitchenAid mixer) for about 20 minutes to introduce air into the combined aqueous mixture. While continuing to whip the combined aqueous mixture, a solution of about 3.77 grams of gluconolactone (GDL) in about 30 mL of water was added to the mixing bowl and whipping was continued for about 1 minute.
  • GDL gluconolactone
  • Example 3 The process as described in Example 3 was repeated except that about 0.97 grams of porcine gelatin, instead of bovine gelatin, was cold-swelled in about 5.8 mL of ultrapure water and then added to the second aqueous mixture and stirred until dissolution was observed.
  • the resulting foam was observed to have a wet foam density of about 0.21 g/cc and a dry foam density of about 0.06 g/cc and was observed to be porous with highly interconnected pores.
  • Figure 7 shows an SEM picture of the foam prepared in this Example 4.
  • Example 5 The process as described in Example 1 was repeated except the first aqueous mixture was prepared by dissolving about 172 grams of 3.0 wt. % polygalacturonic acid sodium salt in demineralized water in an oil bath set at a temperature of 104°C. Additionally, Methocel HPMC Culminal 724 was omitted from the second aqueous mixture. The resulting foam was observed to have a wet foam density of about 0.40 g/cc and a dry foam density of about 0.11 g/cc. The foam was observed to be less porous than the foam formed in Example 1 and the pores were less interconnected than the pores of the foam formed in Example 1.
  • Figure 8 shows an SEM picture of the foam prepared in this Example 5. Although a foam having a wet density of greater than about 0.40 g/cc and a dry density of greater than about 0.11 g/cc was demonstrated as being able to support culturing of cells, foams having a wet density of less than about 0.40 g/cc and a dry density of less than about 0.11 g/cc exhibited improved cell culturing conditions as compared to foams having wet and dry densities such as those possessed by the foam as formed in this Example 5.
  • Example 1 The process as described in Example 1 was repeated except the first aqueous mixture was prepared by dissolving about 162 grams of 1.59 wt. % polygalacturonic acid sodium salt in demineralized water in an oil bath set at a temperature of 104°C. Additionally, the second aqueous mixture was prepared by adding 0.53 grams of CaCCh to about 24.52 grams of ultrapure water and about 2.58 grams Methocel HPMC Culminal 724 was added to the second aqueous mixture. The resulting foam was observed to have a wet foam density of about 0.36 g/cc and a dry foam density of about 0.09 g/cc. Figure 9 shows an SEM picture of the foam prepared in this Example 6.
  • Example 10 shows an SEM picture of the foam prepared in this Example 7.
  • Example 11 shows an SEM picture of the foam prepared in this Example 8.
  • Example 1 The process as described in Example 1 was repeated except the second aqueous mixture was prepared by adding 1.94 grams Pluronic® Pl 23, instead of Methocel HPMC Culminal 724, to the second aqueous mixture.
  • the ratio of PGA to Pluronic P123 in the combined aqueous mixture was controlled to be 62.5/37.5.
  • the resulting foam was observed to have a wet foam density of about 0.18 g/cc and a dry foam density of about 0.03 g/cc and was observed to have a greater porosity than the foam as formed in Example 1.
  • Figure 13 shows an SEM picture of the foam prepared in this Example 10.
  • Example 11 [00114] The process as described in Example 1 was repeated except the second aqueous mixture was prepared by adding a 50:50 weight ratio blend of Pluronic P123 and Dextran instead of Methocel HPMC Culminal 724. The resulting foam was observed to have a wet foam density of about 0.20 g/cc and a dry foam density of about 0.038 g/cc and was observed to have a greater porosity than the foam as formed in Example 1.
  • Figure 14 shows an SEM picture of the foam prepared in this Example 11.
  • Example 11 The process as described in Example 11 was repeated to form multiple foams in which varied amounts of glycerol were added to the second aqueous mixture.
  • a first foam of this example 6.5 grams of glycerol was added the second aqueous mixture.
  • Glycerol constituted 19 wt. % of the total solid additives added to form the combined aqueous mixture.
  • the resulting foam was observed to have a wet foam density of about 0.19 g/cc and a dry foam density of about 0.055 g/cc.
  • 7.5 grams of glycerol was added the second aqueous mixture.
  • Glycerol constituted 22 wt.
  • Glycerol constituted 52 wt. % of the total solid additives added to form the combined aqueous mixture.
  • the resulting foam was observed to have a wet foam density of about 0.26 g/cc and a dry foam density of about 0.35 g/cc.
  • the four foams of Example 12 illustrate the effect of the amount of plasticizer on density and porosity when added during the formation of the foams. Slower drying, greater density and less porosity were observed with increasing plasticizer content. Also, as shown in Figure 15, the generally cylindrical shape of the foam was lost as the amount of glycerol increased above about 20-25 wt. % of the total solid additives added to form the second aqueous mixture.
  • foam 152 represents the sample with 19 wt. % glycerol
  • foam 154 represents the sample with 22 wt. % glycerol
  • foam 156 represents the sample with 42 wt. % glycerol
  • foam 158 represents the sample with 52 wt. % glycerol. It was observed that porosity and interconnectivity of the pores of the foam was greatest when the amount of plasticizer added to the second aqueous mixture was less than about 52 wt. % of the total solid additives added to form the second aqueous mixture.
  • Example 13 The process as described in Example 1 was repeated except the second aqueous mixture was prepared by adding a 50:50 weight ratio blend of Pluronic P127 and Dextran. The resulting foam was observed to have a porosity and interconnectivity of pores similar to the foam prepared in Example 11.
  • Figure 16 shows an SEM picture of the foam prepared in this Example 13.
  • Synthemax® II-SC aqueous ethanol solution About 4.0 mL of the 250 pg/ml Synthemax® II-SC aqueous ethanol solution was added to each of the wells and the plates were then left undisturbed at room temperature for about 1.5 hours. Excess solution was removed from the wells and the foams were washed once with about 5.0 mL of a 70% aqueous ethanol.
  • the Synthemax® II-SC coating was then crosslinked by adding about 4.0 mL of a 0.05% v/v glutaraldehyde in 70% aqueous ethanol (prepared by mixing 40pl of 25% glutaraldehyde solution in 6.0 mL water and 14 mL ethanol). The plates were left undisturbed at room temperature for about 1.5 hours to allow time for crosslinking to occur. The foam was then rinsed three times with ultrapure water.
  • Foams formed in accordance with each of the processes in Examples 1-12 were coated with gelatin.
  • a 0.1 wt. % gelatin solution was prepared by swelling about 500 mg of gelatin powder (from porcine skin) in ultrapure water followed by dissolution and homogenization in 20 mL of ultrapure water.
  • Each of the foams which were about 2-3 mm thick and had diameters of about 22 mm, were placed in separate wells of Polystyrene 6-Well Cell Culture Plates. About 4.0 mL of the gelatin solution was added to each of the wells and the plates were then left undisturbed at room temperature for about 1.5 hours.
  • Vero cells (ATCC® CCL-81, commercially available from ATCC, Manassas, VA) were cultured on cell culture plates in IMDM medium supplemented with 10% fetal bovine serum (FBS). The foam was cut into portions that were about 2-3 mm thick and had diameters of about 22 mm. The foam portions were sanitized in 70% aqueous ethanol for about 5.0 minutes, then placed in separate wells of a 6-Well Ultra-Low Attachment Cell Culture Plate. The foam portions were washed twice in ultrapure water and once in IMDM medium. Excess medium was removed from the wells before seeding.
  • FBS fetal bovine serum
  • Vero cells were harvested from the cell culture plates using trypsin, resuspended in IMDM medium and 150 pL containing about 100,000 cells were seeded in each of the foam portions which were positioned in the wells of the 6-Well Cell Culture Plate.
  • the 6- Cell Culture Plate was placed in a cell culture incubator and, after about 2.0 hours, about 3.0 mL of IMDM medium was added to each well. After about 18 hours in the cell culture incubator, the foam portions were visualized using phase contrast microscopy. An image obtained from the phase contrast microscopy is depicted in Figure 17 which shows that the cells did not adhere to the uncoated foam portions, but instead formed spheroids in the pores of the foam portions.
  • the dissolvable foam scaffolds of the present disclosure may be utilized to culture spheroids or non-adherent cells.
  • hMSC Passage 2 (commercially available from RoosterBio Inc., Frederick, MD) were cultured on cell culture plates in MesencultTM-XF medium (a serum-free medium commercially available from STEMCELL Technologies, Vancouver, BC, Canada). The foam was cut into portions that were about 2-3 mm thick and had diameters of about 22 mm. The foam portions were sanitized in 70% aqueous ethanol for about 5.0 minutes, then placed in separate wells of a 6-Well Ultra-Low Attachment Cell Culture Plate. The foam portions were washed twice in ultrapure water and once in the MesencultTM-XF medium. Excess medium was removed from the wells before seeding.
  • hMSC were harvested from the cell culture plates using trypsin, re-suspended in MesencultTM-XF medium and 150 pL containing about 100,000 cells were seeded in each of the foam portions which were positioned in the wells of the 6-Well Cell Culture Plate.
  • the 6-Well Cell Culture Plate was placed in a cell culture incubator and, after about 2.0 hours, about 3.0 mL of MesencultTM-XF medium was added to each well. After about 18 hours in the cell culture incubator, cells were stained with 1 pg/mL Calcein-AM and visualized using fluorescence microscopy.
  • FIG. 18 An image obtained from the fluorescence microscopy is depicted in Figure 18 which shows that the cells were able to adhere to the foam portions, and spread within the pores of the foam portion.
  • the dissolvable foam scaffolds coated with Coming® Synthemax® II-SC of the present disclosure may be utilized to culture adherent cells in addition to spheroids or non-adherent cells and that the scaffolds support cell culture in serum-free medium.
  • hMSC Passage 2 as used in Example 17 were cultured on cell culture plates in IMDM medium supplemented with 10% fetal bovine serum (FBS). The foam was cut into portions that were about 2-3 mm thick and had diameters of about 22 mm. The foam portions were sanitized in 70% aqueous ethanol for about 5.0 minutes, then placed in separate wells of a 6-Well Ultra-Low Attachment Cell Culture Plate. The foam portions were washed twice in ultrapure water and once in the MesencultTM-XF medium. Excess medium was removed from the wells before seeding.
  • FBS fetal bovine serum
  • hMSC were harvested from the cell culture plates using trypsin, re-suspended in IMDM medium and 150 pL containing about 100,000 cells were seeded in each of the foam portions which were positioned in the wells of the 6-Well Cell Culture Plate.
  • the 6- Well Cell Culture Plate was placed in a cell culture incubator and, after about 2.0 hours, about 3.0 mL of IMDM medium was added to each well. After about 18 hours in the cell culture incubator, cells were stained with 1 pg/mL Calcein-AM and visualized using fluorescence microscopy. An image obtained from the fluorescence microscopy is depicted in Figure 19 which shows that the cells were able to adhere to the foam portions, and spread within the pores of the foam portion.
  • Vero cells as used in Example 16 were cultured on Tissue Culture Treated (TCT) plates in IMDM medium supplemented with 10% fetal bovine serum (FBS).
  • TCT Tissue Culture Treated
  • FBS fetal bovine serum
  • the foam was cut into portions that were about 2-3 mm thick and had diameters of about 22 mm.
  • the foam portions were sanitized in 70% aqueous ethanol for about 5.0 minutes, then placed in separate wells of a Polystyrene 6-Well Cell Culture Plate. The foam portions were washed twice in ultrapure water and once in the IMDM medium. Excess medium was removed from the wells before seeding.
  • Vero cells were harvested from the TCT plates using trypsin and re-suspended in IMDM medium. Some foam portions were seeded with 150 pL containing about 25,000 cells and other foam portions were seeded with 150 pL containing about 50,000 cells, wherein the foam portions were positioned in the well of the 6-Well Cell Culture Plate.
  • the 6-Well Cell Culture Plate was placed in a cell culture incubator for about 6 days. After about 6 days, the medium was removed and the foams were dissolved by the addition to each of the wells of about 2.0 mL of a digestion solution containing about 50 U/mL pectinase and about 5.0 mM EDTA. The foam was observed to dissolve in under 5.0 minutes.
  • hMSC Passage 2 as used in Example 17 were cultured on cell culture plates in MesencultTM-XF medium.
  • the foam was cut into portions that were about 2- 3 mm thick and had diameters of about 22 mm.
  • the foam portions were sanitized in 70% aqueous ethanol for about 5.0 minutes, then placed in separate wells of a Polystyrene 6-Well Cell Culture Plate.
  • the foam portions were washed twice in ultrapure water and once in the MesencultTM-XF medium. Excess medium was removed from the wells before seeding.
  • hMSC were harvested from the cell culture plates using trypsin, re-suspended in MesencultTM-XF medium and 150 pL containing about 100,000 cells were seeded in each of the foam portions which were positioned in the wells of the 6-Well Cell Culture Plate.
  • the 6-Well Cell Culture Plate was placed in a cell culture incubator for about 3 days.
  • osteocyte differentiation medium osteocyte differentiation medium, chondrocyte differentiation medium, and adipocyte differentiation medium (commercially available under the trade name StemProTM Osteogenesis Differentiation Kit, StemProTM Chondrogenesis Differentiation Kit and StemProTM Adipogenesis Differentiation Kit respectfully from Thermo Fisher Scientific, Waltham, MA) was added to the wells, wherein each type of differentiation medium was added to foam portions in different wells than the other types of differentiation medium.
  • foam portions exposed to osteocyte differentiation medium were stained with Alizarin Red
  • foam portions exposed to chondrocyte differentiation medium were stained with Alcian Blue
  • foam portions exposed to adipocyte differentiation medium were stained with Oil Red O.
  • hSMC cultured on dissolvable foam scaffolds coated with gelatin of the present disclosure maintain chondrogenic, osteogenic and adipogenic differentiation.
  • cells cultured on dissolvable foam scaffolds of the present disclosure exhibit biological responses similar to biological responses of cells in-vivo.
  • hMSC Passage 2 as used in Example 17 were cultured on cell culture plates in MesencultTM-XF medium.
  • the foam was cut into portions that were about 2-3 mm thick and had diameters of about 22 mm.
  • the foam portions were sanitized in 70% aqueous ethanol for about 5.0 minutes, then placed in separate wells of a 6- Well Ultra-Low Attachment Cell Culture Plate.
  • the foam portions were washed twice in ultrapure water and once in the MesencultTM-XF medium. Excess medium was removed from the wells before seeding.
  • hMSC were harvested from the cell culture plates using trypsin, re-suspended in MesencultTM-XF medium and 150 pL containing about 100,000 cells were seeded in each of the foam portions which were positioned in the wells of the 6-Well Cell Culture Plate.
  • the 6-Well Cell Culture Plate was placed in a cell culture incubator for about 7 days and medium was removed and replaced with fresh medium on day 4. After about 7 days, the medium was removed, and the foams were dissolved by the addition to each of the wells of about 2.0 mL of a digestion solution containing about 50 U/mL pectinase and about 5.0 mM EDTA. The foam was observed to dissolve in under 5.0 minutes.
  • hMSC Human Mesenchymal Stem Cells
  • a 6-Well Cell Culture Plate containing scaffolds as formed in accordance with Example 2 was removed from the incubator and the scaffolds were transferred to separate bioreactors.
  • the other 6-Well Cell Culture Plates remained in the incubator. All of the scaffolds were kept under their respective conditions for about 6 days and were then dissolved by the addition of a digestion solution containing about 50 U/mL pectinase and about 5.0 mM EDTA. Following dissolution of the foams, cells were counted using the trypan blue exclusion protocol previously described. It was observed that the expansion of cells on the dissolvable foam scaffolds coated with Coming® Synthemax® II- SC of the present disclosure was similar under static conditions as under dynamic conditions.
  • Multi-passage culturing of Human Mesenchymal Stem Cells was investigated. As described herein, the passage number of a cell culture is a record of the number of times the culture has been subcultured, i.e. harvested and reseeded. Thus, multipassage culturing in relation to the present disclosure describes a process wherein cells are harvested from one dissolvable foam scaffold and reseeded on a different dissolvable foam scaffold. hMSC were harvested from the cell culture plates using trypsin, re-suspended in MesencultTM-XF medium and 150 pL containing about 100,000 cells were seeded in a first set of foam scaffolds as formed in Example 2 and as coated in Example 14.
  • the scaffolds were placed in MesencultTM-XF medium and placed in a cell culture incubator for about 6 days. After about 6 days, the scaffolds were dissolved by the addition of a digestion solution containing about 50 U/mL pectinase and about 5.0 mM EDTA. Following dissolution of the foams, cells were counted using the trypan blue exclusion protocol previously described. A solution containing about 100,000 cells that were harvested from the first set of scaffolds was then used to seed a second set of foam scaffolds as formed in Example 2 and as coated in Example 14. The scaffolds were placed in MesencultTM-XF medium and placed in a cell culture incubator for about 7 days.
  • the scaffolds were dissolved by the addition of a digestion solution containing about 50 U/mL pectinase and about 5.0 mM EDTA. Following dissolution of the foams, cells were counted using the trypan blue exclusion protocol. A solution containing about 100,000 cells harvested from the second set of scaffolds was then used to seed a third set of foam scaffolds as formed in Example 2 and as coated in Example 14. The scaffolds were placed in MesencultTM-XF medium and placed in a cell culture incubator for about 7 days. After about 7 days, the scaffolds were dissolved by the addition of a digestion solution containing about 50 U/mL pectinase and about 5.0 mM EDTA.
  • HEK Human embryonic kidney
  • Example 11 Human embryonic kidney
  • Example 14 Transfection of Human embryonic kidney (HEK) cells on a foam scaffold formed in accordance with the process of Example 11 and coated in accordance with the process of Example 14 was compared to the transfection of HEK cells on Coming® Synthemax® II-SC Dissolvable Microcarriers (commercially available from Coming Incorporated, Coming, NY). HEK cells were seeded on the Dissolvable Microcarriers. A first set of Dissolvable Microcarriers were placed in 6-Well Cell Culture Plates and exposed to IMDM medium supplemented with 10% fetal bovine semm (FBS). The 6-Well Cell Culture Plates were placed in a cell incubator and expanded in static conditions for about 3 days.
  • FBS fetal bovine semm
  • a second set of Dissolvable Microcarriers were placed in a disposable spinner flask and suspended in IMDM medium supplemented with 10% fetal bovine serum (FBS) for about 3 days with intermittent stirring (stir for 15 minutes every 2.0 hours). After about 3 days, about 150 pL of a transfection reagent was added to the Dissolvable Microcarriers in the wells of the 6-Well Cell Culture Plates and about 1.0 mL of a transfection reagent was added to the spinner flask with continued intermittent stirring.
  • FBS fetal bovine serum
  • FIG. 1 Portions of foam were seeded with HEK cells. Some foam portions were placed in 6-Well Cell Culture Plates, exposed to IMDM medium supplemented with 10% fetal bovine serum (FBS) and then the 6-Well Culture Plates were placed in a cell incubator for about 3 days. Other foam portions were placed in a chamber of a radial flow perfusion cartridge device for about 3 days. The perfusion cartridge device allowed for the continuous removal of spent IMDM medium supplemented with 10% fetal bovine serum (FBS) and addition of fresh IMDM medium supplemented with 10% fetal bovine serum (FBS) from the chamber.
  • FBS fetal bovine serum
  • transfection efficiency refers to the percentage of cells that have a given nucleic acid or biologically active molecule present within the cell after exposure to a transfection reagent.
  • Figure 21 is a bar graph showing the GFP-positive percentage of the transfected HEK cells for each of the culture conditions.
  • bar 1610 represents the GFP-positive percentage of the transfected HEK cells cultured on the dissolvable foams portions in the 6- Well Cell Culture Plates
  • bar 1620 represents the GFP-positive percentage of the transfected HEK cells cultured on the dissolvable foams portions in the perfusion cartridge device
  • bar 1630 represents the GFP-positive percentage of the transfected HEK cells cultured on Dissolvable Microcarriers in 6-Well Cell Culture Plates
  • bar 1640 represents the GFP- positive percentage of the transfected HEK cells cultured on Dissolvable Microcarriers in the spinner flask.
  • AAV vectors Production of Adeno-Associated Virus (AAV) vectors on a foam scaffolds formed in accordance with the process of Example 11 and coated in accordance with the process of Example 14 was demonstrated.
  • a first and a second set of foam scaffolds were seeded with 1 million 293aav cells and transferred to a chamber of a radial flow perfusion cartridge device where they were exposed to IMDM medium supplemented with 10% fetal bovine serum (FBS).
  • FBS fetal bovine serum
  • cells from the first set of foam scaffolds were transfected with an AAV-2 Helper Free Packaging System (commercially available from Cell Biolabs, Inc., San Diego, CA) using a Calcium Phosphate transfection method.
  • cells from the second set of foam scaffolds were transfected with an AAV-2 Helper Free Packaging System using a PEI method.
  • the Calcium Phosphate method cells were incubated for about 18 hours with calcium phosphate/ DNA complexes prepared with a plasmid concentration of 6.4 pg/mL and a 1:1:1 molar ratio of plasmids.
  • the PEI method cells on the foam scaffolds were transfected with 2pg plasmid/mL. In each of the PEI methods, PEI/DNA ratios of 2/1 and 1:1:1 molar ratio of plasmids were used.
  • the radial flow perfusion cartridge devices were operated at a perfusion rate of 20 mL/min for about 2 hours and then at 5 mL/min for about 16 hours. For all sets of cells, medium was removed and replaced with fresh medium after about 18 hours. Cells were then incubated further and harvested 72 hours after transfection.
  • the foam scaffolds were collected and dissolved by the addition of a digestion solution containing about 50 U/mL pectinase and about 5.0 mM EDTA. Following dissolution of the foam scaffolds, cells were collected using centrifugation and washed in dPBS.
  • FIG. 22 is a bar graph showing the GFP-positive percentage of the transfected cells for each of the sets of foam scaffolds. As shown: bar 1710 represents the GFP-positive percentage of the cells transfected using the Calcium Phosphate transfection method in which transfection method in which transfection efficiency was measured to be about 86.4%; and bar 1720 represents the GFP-positive percentage of the cells transfected using the PEI transfection method in which transfection efficiency was measured to be about 73.8%.
  • Figure 23 is a bar graph showing the number of viral particles (vp) per set of foam scaffold.
  • bar 1810 represents the viral particles of the cells transfected using the Calcium Phosphate transfection method in which 8.7 x 10 11 viral particles were measured; and bar 1820 represents viral particles of the cells transfected using the PEI transfection method in which 5.7 x 10 11 viral particles were measured.
  • Figure 24 is a bar graph showing the number of viral particles per cell per set of foam scaffold.
  • bar 1910 represents the viral parti cles/cell of the cells transfected using the Calcium Phosphate transfection method in which 1.17 x 10 5 viral particles/cell were measured; and bar 1920 represents viral particles/cell of the cells transfected using the PEI transfection method in which 6.8 x 10 4 viral particles/cell were measured.
  • the functionality of the viral vectors was assessed by testing the extracts capacity to induce GFP expression in the infected HEK 293 cells.
  • Viral vector infectivity was assessed by infecting HEK 293 cells with extracts prepared using 10 5 viral particles/cell to infect. About 72 hours after infection, GFP-positive percentage of the infected HEK cells was measured by flow cytometry. Infection was observed for cells from each of the sets of foam scaffolds. GFP expression was used to identify the efficiency of gene transfer, which for the present example ranged from about 10% to about 26%. As such, it was concluded that functional AAV vectors can be produced on foam scaffolds as disclosed herein.
  • Figure 25 is a bar graph showing the fraction of cells exhibiting GFP expression for each of the sets of foam scaffolds after infection.
  • bar 2010 represents the fraction of cells exhibiting GFP expression for the cells transfected using the Calcium Phosphate transfection method in which about 26% of the cells exhibited GFP expression
  • bar 2020 represents the fraction of cells exhibiting GFP expression for the cells transfected using the PEI transfection method in which about 10% of the cells showed GFP expression.
  • Figure 26 is an illustration of an experimental design for investigating the impact of previous cell culture conditions on cell growth performance, transfection efficiency, and viral vector production performance.
  • This experimental design explained below, represents the procedures used in the following Example to produce the data shown in Figures 28-33.
  • a seed train procedure involving one or two colony passages (Pl and P2, respectively) using dissolvable scaffolds according to the present disclosure was compared to a cell culture expansion on a 2D surface.
  • the dissolvable scaffold used is a PGA scaffold as disclosed herein.
  • HEK293T cells (ATCC® number: CRL3216TM) are prepared by growing them on a Coming CellBIND® surface in IMDM supplemented with 10% fetal bovine serum (FBS), penicillin/streptomycine, and 2 mM glutamine. Cells were incubated in a cell culture incubator at 37°C in a water-saturated atmosphere supplemented with 5% CO2. Cells were then harvested using trypsin before they reach confluency.
  • FBS fetal bovine serum
  • penicillin/streptomycine penicillin/streptomycine
  • 2 mM glutamine 2 mM glutamine
  • the scaffolds were placed in the culture chamber of the perfusion reactor then l*10 6 cells per cm 3 of scaffold to be seeded are added to the medium tank.
  • Perfusion speed was set to 1 reactor volume per minute for 3 hours, and then set back to the minimal speed needed to maintain a constant oxygenation.
  • the transfection mix is prepared as described previously for the 2D surface.
  • the culture medium is drained from the scaffold, then 500 pL of transfection mix/mL of scaffolds are added dropwise to the scaffold piece. After 4 hours of incubation in a cell culture incubator, 4 mL of complete medium were added to the well. After 14 more hours of incubation, the medium is renewed, and cells are incubated for 72 additional hours during viral vector production.
  • the transfection mix is prepared as previously described, using equimolar ratio of the 3 plasmids and a PEI/DNA ratio of 2:1.
  • a total amount of 2 pg DNA/mL of medium is used for the transfection.
  • the transfection mix is added to the medium tank and the perfusion speed is set to 1 vol/min for 18 hours. After 18 hours of incubation, the medium is renewed, perfusion speed is set back to minimal speed allowing to maintain a constant oxygenation and cells are incubated for 72 additional hours during viral vector production.
  • HEK293T cells were harvested from a CellBIND® surface, and 300,000 of the harvested cells were seeded in Synthemax®-coated PGA scaffolds and expanded for 4 days in static conditions leading to the harvest of 2 million cells after scaffold dissolution. Acceptable seeding densities range from I / IO 4 to l*10 6 cells per slice.
  • HEK293T cells were harvested from a CellBIND® surface, 300,000 of the harvested cells were seeded in Synthemax®-coated PGA scaffolds and expanded for 4 days in static conditions leading to the harvest of 2 million cells after scaffold dissolution. 300,000 of those harvested cells were then seeded again in Synthemax®-coated PGA scaffolds and expanded for 4 more days in static conditions, leading again to the harvest of 2 million cells.
  • Cells from each of the above three culture origins (2D, Pl, and P2 in Figure 26) were used to seed 2D CellBIND® 6-well plates (50,000 cells/well) or dissolvable scaffold slices in 6-well plates (300,000 cells/slice) for a final expansion and transfection. After 3 days of expansion, cells in 2D conditions or in dissolvable scaffolds were transfected with the AAV plasmids as described above. After 3 more days, cells were harvested and cell growth performance, transfection efficiency, and AAV-GFP vector production were characterized.
  • Figure 27 compares the cell growth performance of cells from different origins (2D, Pl, and P2) that were then finally expanded on a 2D surface, where the growth performance is measured in terms of cell growth ratio.
  • the cell growth performance is relatively comparable for cells from 2D, Pl and P2 origins, ranging from about 75% to about 100%, with the cells originating from the dissolvable scaffolds (Pl and P2) being slightly lower than the cells originating from the 2D surface.
  • Figure 28 shows that the cell growth performance, again in terms of cell growth ratio, is compared for cells from the three different origins (2D, Pl, and P2) that are finally expanded on a dissolvable scaffold. The results are again comparable, with the Pl and P2 cells performing about equally with the 2D-originated cells.
  • Figure 28 shows that the dissolvable scaffold-originated cells (Pl and P2) performed better when their final expansion was also performed on a dissolvable scaffold, as opposed to the final expansion being on a 2D surface (see Figure 27).
  • Figure 29 shows fluorescence microscopy images of green fluorescence protein (GFP) expression for cells from the three different origin conditions (2D, Pl, and P2) that were transfected in 2D conditions (upper row) and in dissolvable scaffolds (lower row).
  • GFP green fluorescence protein
  • Figure 30 shows transfection efficiency ratios for cells transfected on the 2D surface as measured using flow cytometry in 2D for the cells from the different origins (2D, Pl, and P2). The efficiency ratios are based on GFP expression ratios at harvest. The overall transfection efficiency in 2D seems comparable for 2D, Pl, and P2 origin conditions.
  • Figure 31 shows transfection efficiency ratios for cells transfected in dissolvable scaffolds for the cells from the different origins (2D, Pl, and P2). Again, the overall transfection efficiency in the dissolvable scaffold is comparable for 2D, Pl, and P2 origin conditions.
  • FIG. 32 presents the number of viral particles expressed per cell (VP/Cell) obtained for cells finally grown and transfected in 2D, comparing the performance obtained with cells originating from each of the three origin conditions.
  • the results indicate that virus production remains comparable for cells previously grown in dissolvable scaffolds for 1 or 2 passages (Pl or P2, respectively).
  • Figure 33 shows the results obtained for cells finally grown and transfected in dissolvable scaffolds, comparing the performance obtained with cells originating from each of the three origin conditions.
  • This example seed train method is for the seeding of 200 liters of dissolvable scaffold.
  • a working cell bank vial containing 2.5 xlO 7 viable cells is thawed and the cells are transferred to a bioreactor containing 25 mL of dissolvable scaffold.
  • the seeding phase can then be performed as described above.
  • Cells are then incubated for 5 days, recirculation is set, and culture conditions are controlled so that oxygenation and nutrient levels are kept in optimal ranges, and cells culture wastes kept below deleterious ranges. Under these conditions, HEK293T cells should exit lag phase 12- 16 hours after seeding.
  • cell harvest 5 days after seeding should at least provide 5*10 8 cells and remain below cell confluency known to have a deleterious effect on transfection performance for this cell line.
  • Cell harvest should be performed as described above and cells reseeded after washing in a bioreactor containing 500 mL of dissolvable scaffold.
  • Cell expansion of 5*10 8 cells for 5 days should at least produce 12.5* 10 9 sub-confluent cells.
  • a two-passage cell culture seed train was carried out and the cell number was plotted versus the days of the cell culture in Figure 34.
  • cells were harvested at day 6 using Pectinase/EDTA and reseeded.
  • cells were harvested a second time at day 11 (5 days after the first harvest), centrifuged, re-suspended in medium and 100K cells per foam scaffold were reseeded.
  • Transfection was performed on day 14, and a final harvest was performed on day 18.
  • the cumulated cell expansion from this seed train is shown in Figure 35, depicted in the fold expansion over days. As shown, this example seed train method resulted in almost 10,000-fold expansion of cells.
  • a dissolvable foam scaffold for cell culture comprises an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; and at least one first water-soluble polymer having surface activity.
  • the dissolvable foam scaffold of aspect 1 is provided further comprising an adhesion polymer coating.
  • the dissolvable foam scaffold of aspect 2 is provided wherein the adhesion polymer coating comprises peptides.
  • the adhesion polymer coating comprises peptides selected from the group consisting of BSP, vitronectin, fibronectin, laminin, Type I collagen, Type IV collagen, denatured collagen and mixtures thereof.
  • the dissolvable foam scaffold of aspect 2 is provided wherein the adhesion polymer coating comprises Synthemax® II-SC.
  • the dissolvable foam scaffold of any of aspects 1-5 is provided wherein the at least one first polymer has a hydrophilic-lipophilic balance (HLB) of greater than about 8.
  • HLB hydrophilic-lipophilic balance
  • the dissolvable foam scaffold of any of aspects 1-6 wherein the at least one first polymer has a hydrophilic-lipophilic balance (HLB) of greater than about 10.
  • HLB hydrophilic-lipophilic balance
  • the dissolvable foam scaffold of any of aspects 1-7 wherein the at least one first polymer may has a hydrophilic-lipophilic balance (HLB) of between about 10 and about 40.
  • HLB hydrophilic-lipophilic balance
  • the dissolvable foam scaffold of any of aspects 1-8 is provided wherein the at least one first polymer comprises a cellulose derivative.
  • the dissolvable foam scaffold of aspect 9 is provided wherein the cellulose derivative is selected from the group consisting of hydroxy ethylcellulose (HEC), hydroxypropylcellulose (HPC), methylcellulose (MC), hydroxyethylmethylcellulose (HEMC), and hydroxypropyl-methylcellulose (HPMC).
  • HEC hydroxy ethylcellulose
  • HPC hydroxypropylcellulose
  • MC methylcellulose
  • HEMC hydroxyethylmethylcellulose
  • HPMC hydroxypropyl-methylcellulose
  • the dissolvable foam scaffold of any of aspects 1-8 is provided wherein the at least one first polymer comprises a protein.
  • the protein is selected from the group consisting of bovine serum albumin (BSA), gelatine, casein and hydrophobins.
  • the dissolvable foam scaffold of any of aspects 1-8 is provided wherein the at least one first polymer comprises a synthetic amphiphilic polymer.
  • the dissolvable foam scaffold of aspect 13 is provided wherein the synthetic amphiphilic polymer comprises a poloxamer.
  • the dissolvable foam scaffold of any of aspects 1-14 comprising at least two first water-soluble polymers having surface activity.
  • the dissolvable foam scaffold of any of aspects 1-15 is provided further comprising at least one second polymer having no surface activity.
  • the dissolvable foam scaffold of aspect 16 is provided wherein the at least one second polymer comprises a synthetic polymer.
  • the dissolvable foam scaffold of aspect 17 wherein the synthetic polymer is selected from the group consisting of polyethylene glycol, polyvinyl pyrrolidone, polyvinyl alcohol, carboxyvinyl polymer, polyacrylic acid, polyacrylamide, homopolymer and copolymer of N-(2- Hydroxypropyl) methacrylamide, polyvinyl methyl ether-maleic anhydride, and polyethylene oxide/polypropylene oxide block copolymers.
  • the synthetic polymer is selected from the group consisting of polyethylene glycol, polyvinyl pyrrolidone, polyvinyl alcohol, carboxyvinyl polymer, polyacrylic acid, polyacrylamide, homopolymer and copolymer of N-(2- Hydroxypropyl) methacrylamide, polyvinyl methyl ether-maleic anhydride, and polyethylene oxide/polypropylene oxide block copolymers.
  • the dissolvable foam scaffold of aspect 16 is provided wherein the at least one second polymer comprises a semisynthetic polymer.
  • the dissolvable foam scaffold of aspect 19 is provided wherein the semisynthetic polymer is selected from the group consisting of dextran derivatives, carboxymethyl cellulose, hydroxyethyl cellulose and derivatives, methylcellulose and derivatives, ethylcellulose cellulose, ethyl hydroxyethyl cellulose, and hydroxypropyl cellulose.
  • the dissolvable foam scaffold of aspect 16 is provided wherein the at least one second polymer comprises a natural polymer.
  • the dissolvable foam scaffold of aspect 21 wherein the natural polymer is selected from the group consisting of starch, starch derivatives, curdlan, pullulan, gellan gum, xanthan gum, dextran, albumin, casein, caseinates, gelatin, agar, alginates, carrageenan, guar gum, guar gum derivatives, locust bean gum, hyaluronic acid, and chondroitin sulfate.
  • the natural polymer is selected from the group consisting of starch, starch derivatives, curdlan, pullulan, gellan gum, xanthan gum, dextran, albumin, casein, caseinates, gelatin, agar, alginates, carrageenan, guar gum, guar gum derivatives, locust bean gum, hyaluronic acid, and chondroitin sulfate.
  • the dissolvable foam scaffold of any of aspects 1-22 is provided further comprising a water soluble plasticizer.
  • the dissolvable foam scaffold of aspect 23 is provided wherein the water soluble plasticizer is selected from the group consisting of glycerol, polyhydric alcohol, sorbitol, ethylene glycol, propylene glycol, polyethylene glycol and combinations thereof.
  • the water soluble plasticizer is selected from the group consisting of glycerol, polyhydric alcohol, sorbitol, ethylene glycol, propylene glycol, polyethylene glycol and combinations thereof.
  • the dissolvable foam scaffold of any of aspects 23-24 is provided comprising less than about 55 wt. % water soluble plasticizer.
  • the dissolvable foam scaffold of any of aspects 23-25 is provided comprising between about 15 wt. % and about 55 wt. % water soluble plasticizer.
  • the dissolvable foam scaffold of any of aspects 1-26 is provided comprising a porosity of between about 85% and about 96%.
  • the dissolvable foam scaffold of any of aspects 1-27 is provided comprising an average pore size diameter of between about 50 pm and about 500 pm.
  • the dissolvable foam scaffold of any of aspects 1-28 comprising an average pore size diameter of between about 75 pm and about 450 pm.
  • the dissolvable foam scaffold of any of aspects 1-29 comprising an average pore size diameter of between about 100 pm and about 400 pm.
  • the dissolvable foam scaffold of any of aspects 1-30 comprising a wet density of less than about 0.40 g/cc.
  • the dissolvable foam scaffold of any of aspects 1-31 comprising a wet density of less than about 0.30 g/cc.
  • the dissolvable foam scaffold of any of aspects 1-32 comprising a wet density of between about 0.16 g/cc and about 0.40 g/cc.
  • the dissolvable foam scaffold of any of aspects 1-33 comprising a dry density of less than about 0.20 g/cc.
  • the dissolvable foam scaffold of any of aspects 1-34 comprising a dry density of less than about 0.10 g/cc.
  • the dissolvable foam scaffold of any of aspects 1-35 is provided comprising a dry density of between about 0.02 g/cc and about 0.20 g/cc.
  • the dissolvable foam scaffold of any of aspects 1-36 is provided comprising an open pore architecture.
  • the dissolvable foam scaffold of any of aspects 1-37 is provided wherein digestion of the dissolvable foam scaffold is complete in less than about 1 hour.
  • the dissolvable foam scaffold of any of aspects 1-38 is provided wherein digestion of the dissolvable foam scaffold is complete in less than about 15 minutes.
  • a method for forming a dissolvable foam scaffold comprises: forming a first aqueous mixture by adding a polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof to an aqueous solution; forming a second aqueous mixture by adding at least one first water- soluble polymer having surface activity and a divalent metal salt to an aqueous solution; combining the first aqueous mixture with second first aqueous mixture to form a combined aqueous mixture; adding a gel inducing agent to the combined aqueous mixture; and introducing gas bubbles into the combined aqueous mixture to form a foam scaffold.
  • a polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof to an aqueous solution
  • forming a second aqueous mixture by adding at least one first water- soluble
  • the method of aspect 40 is provided wherein forming a second aqueous mixture further comprises adding at least one second polymer having no surface activity.
  • adding at least one first polymer and at least one second polymer comprises adding between about 35% and about 65% of the at least one first polymer and between about 35% and about 65% of the at least one second polymer.
  • the method of any of aspects 40-42 is provided wherein forming a second aqueous mixture comprises adding at least two first water-soluble polymers having surface activity.
  • the divalent metal salt comprises: a cation selected from the group consisting of magnesium, calcium, zinc, strontium, barium, and combinations thereof; and an anion selected from the group consisting of oxalates, tartrates, phosphates, carbonates, citrates, and combinations thereof.
  • the method of any of aspects 40-43 is provided wherein forming a second aqueous mixture further comprises adding a water soluble plasticizer to the second aqueous mixture.
  • the method of aspect 45 is provided wherein the water soluble plasticizer is selected from the group consisting of glycerol, polyhydric alcohol, sorbitol, ethylene glycol, propylene glycol, polyethylene glycol and combinations thereof.
  • the method of any of aspects 45-46 is provided wherein the water soluble plasticizer comprises less than about 55 wt. % of the total solid additives of the second aqueous mixture.
  • the method of any of aspects 45-47 is provided wherein the water soluble plasticizer comprises between about 15 wt. % and about 55 wt. % of the total solid additives of the second aqueous mixture.
  • the method of any of aspects 40-48 is provided wherein forming a second aqueous mixture further comprises adding an emulsifying agent to the second aqueous mixture.
  • the method of any of aspects 40-48 is provided wherein forming a second aqueous mixture further comprises adding an emulsifying agent to the second aqueous mixture.
  • the method of any of aspects 40-49 is provided wherein forming a second aqueous mixture further comprises adding at least one leachable solid to the second aqueous mixture.
  • the at least one leachable solid is selected from the group consisting of salts, biocompatible mono and disaccharides and water-soluble proteins.
  • the method of any of aspects 40-51 is provided wherein the gel inducing agent is selected from the group consisting of lactic acid lactone, glycolic acid lactone, glucono delta lactone and acid anhydrides.
  • the method of any of aspects 40-52 is provided, further comprising coating the dissolvable foam scaffold with an adhesion polymer coating.
  • the method of aspect 53 is provided wherein the adhesion polymer coating comprises peptides.
  • the method of aspect 53 is provided wherein the adhesion polymer coating comprises peptides selected from the group consisting of BSP, vitronectin, fibronectin, laminin, Type I collagen, Type IV collagen, denatured collagen and mixtures thereof.
  • the method of aspect 53 is provided wherein the adhesion polymer coating comprises Synthemax® II-SC.
  • a method for culturing cells on a dissolvable foam scaffold comprises: seeding cells on a dissolvable foam scaffold such that cells enter pores of the dissolvable foam scaffold, the dissolvable scaffold comprising: an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; and at least one first water-soluble polymer having surface activity; and contacting the dissolvable foam scaffold with cell culture medium.
  • the method of aspect 57 is provided wherein cells aggregate in the pores of the dissolvable foam scaffold to form spheroids.
  • the method of any of aspects 57-58 is provided wherein the dissolvable foam scaffold comprises an adhesion polymer coating and wherein seeding cells on a dissolvable foam scaffold comprises adhering cells to the surface of the dissolvable foam scaffold.
  • contacting the dissolvable foam scaffold with cell culture medium comprises submerging the dissolvable foam scaffold in cell culture medium.
  • contacting the dissolvable foam scaffold with cell culture medium comprises continuously passing cell culture medium over the dissolvable foam scaffold.
  • the method of aspect 61 comprises removing at least some of the cell culture medium from contact with the dissolvable foam scaffold and contacting the dissolvable foam scaffold with fresh cell culture medium such that the volume of cell culture medium in contact with the dissolvable foam scaffold remains substantially constant.
  • a method of harvesting cells from a dissolvable foam scaffold comprises: digesting the dissolvable foam scaffold by exposing the dissolvable foam scaffold to an enzyme; the dissolvable scaffold comprising: an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; and at least one first water-soluble polymer having surface activity; and exposing the dissolvable foam scaffold to a chelating agent.
  • the method of aspect 63 is provided wherein the enzyme comprises a non-proteolytic enzyme.
  • the method of aspect 64 is provided wherein the non-proteolytic enzyme is selected from the group consisting of pectinolytic enzymes and pectinases.
  • the method of any of aspects 63-65 is provided wherein digesting the dissolvable foam scaffold comprises exposing the dissolvable foam scaffold to between about 1 U and about 200 U of the enzyme.
  • the method of any of aspects 63-66 comprising exposing the dissolvable foam scaffold to between about 1 mM and about 200 mM of the chelating agent.
  • a foamed scaffold product formed from a composition comprises: an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; at least one first water-soluble polymer having surface activity; and less than about 55 wt. % water soluble plasticizer.
  • the foamed scaffold product of aspect 68 is provided further comprising an adhesion polymer coating.
  • the foamed scaffold product of aspect 69 is provided wherein the adhesion polymer coating comprises peptides.
  • the foamed scaffold product of aspect 69 wherein the adhesion polymer coating comprises peptides selected from the group consisting of BSP, vitronectin, fibronectin, laminin, Type I collagen, Type IV collagen, denatured collagen and mixtures thereof.
  • the foamed scaffold product of aspect 69 is provided wherein the adhesion polymer coating comprises Synthemax® II-SC.
  • the foamed scaffold product of any of aspects 68-72 is provided wherein the at least one first polymer has a hydrophilic-lipophilic balance (HLB) of greater than about 8.
  • the foamed scaffold product of any of aspects 68-73 is provided wherein the at least one first polymer has a hydrophilic-lipophilic balance (HLB) of greater than about 10.
  • the foamed scaffold product of any of aspects 68-74 is provided wherein the at least one first polymer may has a hydrophilic-lipophilic balance (HLB) of between about 10 and about 40.
  • HLB hydrophilic-lipophilic balance
  • the foamed scaffold product of any of aspects 68-75 is provided wherein the at least one first polymer comprises a cellulose derivative.
  • the foamed scaffold product of aspect 76 is provided wherein the cellulose derivative is selected from the group consisting of hydroxy ethylcellulose (HEC), hydroxypropylcellulose (HPC), methylcellulose (MC), hydroxyethylmethylcellulose (HEMC), and hydroxypropyl-methylcellulose (HPMC).
  • HEC hydroxy ethylcellulose
  • HPC hydroxypropylcellulose
  • MC methylcellulose
  • HEMC hydroxyethylmethylcellulose
  • HPMC hydroxypropyl-methylcellulose
  • the foamed scaffold product of any of aspects 68-75 is provided wherein the at least one first polymer comprises a protein.
  • the foamed scaffold product of aspect 78 is provided wherein the protein is selected from the group consisting of bovine serum albumin (BSA), gelatine, casein and hydrophobins.
  • BSA bovine serum albumin
  • gelatine gelatine
  • casein casein
  • hydrophobins hydrophobins
  • the foamed scaffold product of any of aspects 68-75 is provided wherein the at least one first polymer comprises a synthetic amphiphilic polymer.
  • the foamed scaffold product of aspect 80 is provided wherein the synthetic amphiphilic polymer comprises a poloxamer.
  • the foamed scaffold product of any of aspects 68-81 is provided comprising at least two first water-soluble polymers having surface activity.
  • the foamed scaffold product of any of aspects 68-82 is provided wherein the foam scaffold composition further comprises at least one second polymer having no surface activity.
  • the foamed scaffold product of aspect 83 is provided wherein the at least one second polymer comprises a synthetic polymer.
  • the foamed scaffold product of aspect 84 is provided wherein the synthetic polymer is selected from the group consisting of polyethylene glycol, polyvinyl pyrrolidone, polyvinyl alcohol, carboxyvinyl polymer, polyacrylic acid, polyacrylamide, homopolymer and copolymer of N-(2- Hydroxypropyl) methacrylamide, polyvinyl methyl ether-maleic anhydride, and polyethylene oxide/polypropylene oxide block copolymers.
  • the synthetic polymer is selected from the group consisting of polyethylene glycol, polyvinyl pyrrolidone, polyvinyl alcohol, carboxyvinyl polymer, polyacrylic acid, polyacrylamide, homopolymer and copolymer of N-(2- Hydroxypropyl) methacrylamide, polyvinyl methyl ether-maleic anhydride, and polyethylene oxide/polypropylene oxide block copolymers.
  • the foamed scaffold product of aspect 83 is provided wherein the at least one second polymer comprises a semisynthetic polymer.
  • the foamed scaffold product of aspect 86 is provided wherein the semisynthetic polymer is selected from the group consisting of dextran derivatives, carboxymethyl cellulose, hydroxyethyl cellulose and derivatives, methylcellulose and derivatives, ethylcellulose cellulose, ethyl hydroxyethyl cellulose, and hydroxypropyl cellulose.
  • the foamed scaffold product of aspect 83 is provided wherein the at least one second polymer comprises a natural polymer.
  • the foamed scaffold product of aspect 88 is provided wherein the natural polymer is selected from the group consisting of starch, starch derivatives, curdlan, pullulan, gellan gum, xanthan gum, dextran, albumin, casein, caseinates, gelatin, agar, alginates, carrageenan, guar gum, guar gum derivatives, locust bean gum, hyaluronic acid, and chondroitin sulfate.
  • the natural polymer is selected from the group consisting of starch, starch derivatives, curdlan, pullulan, gellan gum, xanthan gum, dextran, albumin, casein, caseinates, gelatin, agar, alginates, carrageenan, guar gum, guar gum derivatives, locust bean gum, hyaluronic acid, and chondroitin sulfate.
  • the foamed scaffold product of any of aspects 68-89 is provided wherein the water soluble plasticizer is selected from the group consisting of glycerol, polyhydric alcohol, sorbitol, ethylene glycol, propylene glycol, polyethylene glycol and combinations thereof.
  • the water soluble plasticizer is selected from the group consisting of glycerol, polyhydric alcohol, sorbitol, ethylene glycol, propylene glycol, polyethylene glycol and combinations thereof.
  • the foamed scaffold product of any of aspects 68-90 comprising between about 15 wt. % and about 55 wt. % water soluble plasticizer.
  • the foamed scaffold product of any of aspects 68-91 comprising a porosity of between about 85% and about 96%.
  • the foamed scaffold product of any of aspects 68-92 is provided comprising an average pore size diameter of between about 50 pm and about 500 pm.
  • the foamed scaffold product of any of aspects 68-93 is provided comprising an average pore size diameter of between about 75 pm and about 450 pm.
  • the foamed scaffold product of any of aspects 68-94 comprising an average pore size diameter of between about 100 pm and about 400 pm.
  • the foamed scaffold product of any of aspects 68-95 comprising a wet density of less than about 0.40 g/cc.
  • the foamed scaffold product of any of aspects 68-96 is provided comprising a wet density of less than about 0.30 g/cc.
  • the foamed scaffold product of any of aspects 68-97 is provided comprising a wet density of between about 0.16 g/cc and about 0.40 g/cc.
  • the foamed scaffold product of any of aspects 68-98 is provided comprising a dry density of less than about 0.20 g/cc.
  • the foamed scaffold product of any of aspects 68-99 comprising a dry density of less than about 0.10 g/cc.
  • the foamed scaffold product of any of aspects 68-100 comprising a dry density of between about 0.02 g/cc and about 0.20 g/cc.
  • the foamed scaffold product of any of aspects 68-101 is provided comprising an open pore architecture.
  • a method of cell seed train expansion comprising: providing a first cell culture substrate comprising a dissolvable foam scaffold; delivering cells and a cell culture media to the first cell culture substrate, the cells being seeded on or in the dissolvable foam scaffold of the first cell culture substrate; controlling environmental conditions and composition of the cell culture media to promote culturing of the cells on the first cell culture substrate; dissolving the dissolvable foam scaffold of the first cell culture substrate to form a solution containing the cells; harvesting the cells from the solution; and reseeding at least a portion of the cells that were harvested onto a second cell culture substrate of the dissolvable foam scaffold, wherein the dissolvable foam scaffold of the first cell culture substrate is the same material as the dissolvable foam scaffold of the second cell culture substrate.
  • the method of Aspect 103 is provided, wherein the first and second cell culture substrates are three-dimensional cell culture scaffolds.
  • the method of Aspect 103 or 104 is provided, further comprising: delivering cell culture media to the second cell culture substrate; and controlling environmental conditions and composition of the cell culture media to promote culturing of the cells in the dissolvable foam scaffold of the second cell culture substrate.
  • the method of Aspect 105 further comprising dissolving the dissolvable foam scaffold of the second cell culture substrate and harvesting the cells therefrom.
  • the method of Aspect 106 is provided, further comprising reseeding at least a portion of the cells that were harvested from the second cell culture substrate onto a third cell culture substrate of the dissolvable foam scaffold, wherein the dissolvable foam scaffold of the third cell culture substrate is the same material as the dissolvable foam scaffold of the second cell culture substrate.
  • the method of Aspect 103 is provided, further comprising thawing a cryopreserved cell bank to provide the cells for delivery to the first cell culture substrate.
  • the method of Aspect 103 or Aspect 108 is provided, wherein the cells are obtained from a cryovial.
  • the method of Aspect 103 wherein the cells are seeded on the first cell culture substrate such that the cells enter pores of the dissolvable foam scaffold.
  • the method of Aspect 103 is provided, wherein the dissolvable foam scaffold is disposed in a container configured to hold the cell culture media.
  • the method of Aspect 111 is provided, wherein the container is a perfusion bioreactor.
  • the method of Aspect 103 wherein the cells comprise adherent or semi-adherent cells.
  • the method of Aspect 103 wherein the cells comprise Vero cells, Human embryonic kidney (HEK) cells, or Human Mesenchymal Stem Cells (hMSC).
  • HEK Human embryonic kidney
  • hMSC Human Mesenchymal Stem Cells
  • the method of any of Aspects 103-114 is provided, wherein at least one of the first and second cell culture substrate are arranged as a packed bed within a bioreactor.
  • the method of any of Aspects 103-115 is provided, wherein the dissolvable foam scaffold is dissolved via exposure to an enzyme.
  • the enzyme comprises a non-proteolytic enzyme.
  • non-proteolytic enzyme is selected from the group consisting of pectinolytic enzymes and pectinases.
  • the method of Aspect 119 is provided, wherein a volume of the third cell culture substrate is greater than the volume of the second cell culture substrate.
  • the method of any of Aspects 103-120 is provided, further comprising transfecting the cells after being reseeded.
  • the method of any of Aspects 103-121 is provided, wherein the dissolvable foam scaffold comprises: an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; and at least one first water-soluble polymer having surface activity.
  • the method of Aspect 122 is provided, the dissolvable foam scaffold further comprising a water soluble plasticizer.
  • the method of Aspect 123 is provided, the dissolvable foam scaffold comprising less than about 55 wt. % water soluble plasticizer.
  • the method of any of Aspects 122-124 is provided, the dissolvable foam scaffold further comprising an adhesion polymer coating.
  • the method of Aspect 125 is provided, wherein the adhesion polymer coating comprises peptides.
  • the method of Aspect 125 comprises peptides selected from the group consisting of BSP, vitronectin, fibronectin, laminin, Type I collagen, Type IV collagen, denatured collagen and mixtures thereof.
  • the method of Aspect 125 wherein the adhesion polymer coating comprises Synthemax® II- SC.
  • the method of any of Aspects 122-128 is provided, wherein the at least one first polymer has a hydrophilic- lipophilic balance (HLB) of greater than about 8.
  • HLB hydrophilic- lipophilic balance
  • the method of any of Aspects 122-129 is provided, wherein the at least one first polymer comprises a protein.
  • the method of any of Aspects 122-129 is provided, wherein the at least one first polymer comprises a synthetic amphiphilic polymer.
  • the method of any of Aspects 122-132 is provided, the dissolvable foam scaffold further comprising at least two first water-soluble polymers having surface activity.
  • the method of any of Aspects 122-133 is provided, the dissolvable foam scaffold further comprising at least one second polymer having no surface activity.
  • the method of Aspect 134 is provided, wherein the at least one second polymer comprises a synthetic polymer.
  • the method of Aspect 134 is provided, wherein the at least one second polymer comprises a semisynthetic polymer.
  • the method of Aspect 134 is provided, wherein the at least one second polymer comprises a natural polymer.
  • the method of any of Aspects 122-137 is provided, the dissolvable foam scaffold further comprising an average pore size diameter of between about 50 pm and about 500 pm.
  • the method of any of Aspects 122-138 is provided, the dissolvable foam scaffold further comprising a wet density of less than about 0.40 g/cc.
  • the method of any of Aspects 122-139 is provided, the dissolvable foam scaffold further comprising an open pore architecture.
  • the method of any of Aspects 122-140 is provided, wherein digestion of the dissolvable foam scaffold is complete in less than about 1 hour.
  • a method of cell seed train expansion for scaling a cell sample to a production scale reactor comprising: expanding the cell sample containing cells on a first dissolvable foam scaffold; expanding at least a portion of the cells harvested from the first dissolvable foam scaffold onto a second dissolvable foam scaffold; seeding at least a portion of the cells harvested from at least one of the first dissolvable foam scaffold and the second dissolvable foam scaffold onto a third dissolvable foam scaffold, wherein the first, second, and third dissolvable foam scaffold comprise the same scaffold material.
  • the method of Aspect 142 comprises: seeding the cells on the first dissolvable foam scaffold; expanding the cells to increase the number of the cells; dissolving the first dissolvable foam scaffold to form a first harvest solution; and harvesting the cells from the first harvest solution.
  • the method of Aspect 142 or 143 comprises: seeding the cells on the second dissolvable foam scaffold; expanding the cells to increase the number of the cells; dissolving the second dissolvable foam scaffold to form a second harvest solution; and harvesting the cells from the second harvest solution.
  • a volume of the second dissolvable foam scaffold is greater than a volume of the first dissolvable foam scaffold.
  • the method of any of Aspects 142-145 is provided, wherein the first dissolvable foam scaffold has a volume of about 10 mL to about 300 mL, about 10 mL to about 100 mL, or about 25 mL to about 50 mL.
  • the method of any of Aspects 142-146 is provided, wherein the second dissolvable foam scaffold has a volume of from about 100 mL to about 1000 mL, from about 200 mL to about 900 mL, from about 300 mL to about 800 mL, from about 400 mL to about 600 mL, from about 450 mL to about 550 mL, or about 500 mL.
  • the method of any of Aspects 142-147 is provided, wherein the third dissolvable foam scaffold has a volume of from about 1 L to about 500 L, from about 1 L to about 100 L, from about 100 L to about 200 L, from about 200 L to about 300 L, from about 300 L to about 400 L, from about 400 L to about 500 L, at least about 500 L, from about 1 L to about 20 L, from about 5 L to about 15 L, or about 10 L.
  • the method of any of Aspects 142-148 is provided, wherein at least one of the first, second, and third dissolvable foam scaffolds comprise: an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; and at least one first water-soluble polymer having surface activity.
  • an ionotropically crosslinked polygalacturonic acid compound selected from at least one of: pectic acid; partially esterified pectic acid, partially amidated pectic acid and salts thereof; and at least one first water-soluble polymer having surface activity.

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Abstract

L'invention concerne un procédé d'expansion de chaîne d'ensemencement cellulaire. Le procédé comprend les étapes consistant à utiliser un premier substrat de culture cellulaire constitué d'un support en mousse soluble, à introduire des cellules et un milieu de culture cellulaire dans le premier substrat de culture cellulaire, et à ensemencer avec elles le support en mousse soluble du premier substrat de culture cellulaire. Les conditions environnementales et la composition du milieu de culture cellulaire sont régulées pour favoriser la culture des cellules sur le premier substrat de culture cellulaire, et le support en mousse soluble du premier substrat de culture cellulaire est ensuite dissous pour former une solution contenant les cellules, qui sont récoltées dans la solution. Le réensemencement, avec au moins une partie des cellules qui ont été récoltées, d'un second substrat de culture cellulaire à support en mousse soluble est effectué. Le support en mousse soluble des premier et second substrats de culture cellulaire est constitué du même matériau.
PCT/US2021/053711 2020-10-08 2021-10-06 Procédés et systèmes de récolte et de réensemencement de culture cellulaire utilisant des substrats solubles WO2022076519A1 (fr)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023228182A1 (fr) * 2022-05-23 2023-11-30 Pluri Biotech Ltd. Système et procédés pour la multiplication et l'activation de cellules immunitaires à grande échelle
WO2024029629A1 (fr) * 2022-08-04 2024-02-08 三栄源エフ・エフ・アイ株式会社 Échafaudage poreux pour culture cellulaire et son procédé de production
WO2023217767A3 (fr) * 2022-05-09 2024-02-15 Imperial College Innovations Limited Groupes d'organoïdes portés par un échafaudage pour l'agrégation d'organoïdes in vitro à haut débit contrôlée et formation de motifs organoïdes régionaux
WO2024107344A1 (fr) * 2022-11-14 2024-05-23 Corning Incorporated Structures en mousse solubles pour la culture cellulaire et leurs procédés de fabrication

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Publication number Priority date Publication date Assignee Title
WO2016200888A1 (fr) * 2015-06-08 2016-12-15 Corning Incorporated Substrats digestibles pour culture cellulaire
WO2019104069A1 (fr) * 2017-11-21 2019-05-31 Corning Incorporated Échafaudages solubles de mousse pour la culture cellulaire et procédés pour leur fabrication
WO2020150078A1 (fr) * 2019-01-16 2020-07-23 Corning Incorporated Systèmes et procédés de culture de cellules en suspension

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016200888A1 (fr) * 2015-06-08 2016-12-15 Corning Incorporated Substrats digestibles pour culture cellulaire
WO2019104069A1 (fr) * 2017-11-21 2019-05-31 Corning Incorporated Échafaudages solubles de mousse pour la culture cellulaire et procédés pour leur fabrication
WO2020150078A1 (fr) * 2019-01-16 2020-07-23 Corning Incorporated Systèmes et procédés de culture de cellules en suspension

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023217767A3 (fr) * 2022-05-09 2024-02-15 Imperial College Innovations Limited Groupes d'organoïdes portés par un échafaudage pour l'agrégation d'organoïdes in vitro à haut débit contrôlée et formation de motifs organoïdes régionaux
WO2023228182A1 (fr) * 2022-05-23 2023-11-30 Pluri Biotech Ltd. Système et procédés pour la multiplication et l'activation de cellules immunitaires à grande échelle
US11939562B2 (en) 2022-05-23 2024-03-26 Pluri Biotech Ltd. System and methods for immune cells expansion and activation in large scale
WO2024029629A1 (fr) * 2022-08-04 2024-02-08 三栄源エフ・エフ・アイ株式会社 Échafaudage poreux pour culture cellulaire et son procédé de production
WO2024107344A1 (fr) * 2022-11-14 2024-05-23 Corning Incorporated Structures en mousse solubles pour la culture cellulaire et leurs procédés de fabrication

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