Abstract: A bioreactor carrier is provided using an organic polymer substance having a water absorptivity of 50 to 1,700%, and containing an inorganic salt, organic nitrogen source and/or organic carbon source utilizable as a nutrient by animal cells, plant cells and/or microorganisms which fix to the carrier for uses such as substance production, harmful substance treatment, waste oil treatment, wastewater treatment and deodorization. A preferred polymer substance is a water swellable thermoplastic polyurethane gel having the water absorptivity and a swelling rate of volume of 150 to 4,000%. The polyurethane gel is obtained by reacting together a long-chain diol compound, a short-chain diol compound and a diisocyanate compound. The long-chain diol compound has a number-average molecular weight of 400 to 10,000, and is selected from an ethylene oxide-propylene oxide copolymer having an ethylene oxide content not less than 70% and a polyethylene glycol.

Abstract: Isolated chondrocytes are propagated in the presence of a biological gel such as a fibrin gel to generate a cartilage matrix that firmly bonds together two adjacent cartilage pieces. A bonding composition containing the isolated chondrocytes mixed with the biological gel is applied to a surface of one (or both) of the cartilage pieces, and the surface is contacted with the other cartilage piece. In a different order of steps, the two cartilage pieces are held in apposition, and gaps at the interface are filled with the bonding composition. In another method, either or both of the cartilage pieces are first incubated with the isolated chondrocytes, the biological gel is then applied, and the cartilage pieces are held together. Alternatively, after incubating with isolated chondrocytes, the biological gel can be applied to fill gaps at the interface between cartilage pieces held in apposition.

Abstract: A bioartificial extracellular matrix for use in tissue regeneration or replacement is provided by derivatizing a three-dimensional hydrogel matrix with a cell adhesive extracellular matrix protein or cell adhesive peptide fragment of the protein. Preferably, derivatizing is by covalent immobilization of a cell adhesive peptide fragment having the amino acid sequence, ArgGlyAsp, TyrIleGlySerArg or IleLysValAlaVal. Cartilage or tendon can be regenerated by implanting a matrix containing an adhesive peptide fragment that favors chondrocyte invasion. The matrix can be pre-seeded with cells, and tissue can be reconstituted in vitro and then implanted. A cell-seeded matrix can be encapsulated in a semi-permeable membrane to form a bioartificial organ. An agarose hydrogel matrix having an agarose concentration of 0.5-1.25% (w/v) and an average pore radius between 120 nm and 290 nm is preferred.

Abstract: A bioreactor carrier is provided composed of a water absorption gel of a crosslinked N-vinylcarboxamide resin which has a great moisture content and excellent physical strength, is not eroded by microorganisms and is easily mass-produced on an industrial scale. The gel is obtained by swelling and gelling a crosslinked N-vinylcarboxamide resin made from an N-vinylcarboxamide such as N-vinylacetoamide. The swollen gel may be in the form of beads of 1.0 to 20 mm, and the resin when swollen with water has a water absorption coefficient of 500 to 3500%. Resin beads may be swollen in a suspension of a biocatalyst such as animal cells, plant cells, microorganisms or protozoans to bind and immobilize the biocatalyst to form a bioreactor. The microorganisms can be nitrate bacteria, denitrification bacteria or Hyphomycetes, and the bioreactor may be used to treat waste water or for deodorizing.

Abstract: Microcapsules and composite microreactors are prepared that immunoisolate living cells such as islet cells or genetically engineered cells. A reduced volume microcapsule is formed by coating a gel matrix particle with a polyamino acid of 15,000 daltons or less molecular weight to reduce volume of the particle by at least 30% as compared to volume prior to coating. A composite microreactor includes the microcapsule containing cell embedded in a gel matrix and provides a molecular weight cutoff that prevents molecules larger than about 400,000 daltons from containing the living cell. A double composite microreactor includes an internal particle that includes an internal particle gel matrix containing a living cell and having a coating, a particle that includes the internal particle embedded in a particle gel matrix and a coating, and a gel super matrix in which the particle is embedded. At least one of the coatings is a volume reducing coating of polyamino acid of 15,000 daltons or less molecular weight.

Abstract: A gelling cell culture medium useful for forming a three dimensional matrix for cell culture in vitro is prepared by copolymerizing an acrylamide derivative with a hydrophilic comonomer to form a reversible (preferably thermally reversible) gelling linear random copolymer in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum gelling molecular weight cutoff, mixing the copolymer with an aqueous solvent to form a reversible gelling solution and adding a cell culture medium to the gelling solution to form the gelling cell culture medium. Cells such as chondrocytes or hepatocytes are added to the culture medium to form a seeded culture medium, and temperature of the medium is raised to gel the seeded culture medium and form a three dimensional matrix containing the cells. After propagating the cells in the matrix, the cells may be recovered by lowering the temperature to dissolve the matrix and centrifuging.

Abstract: After the cryopreservation of living cells, the cells in a post-thaw recovery stage are supported by a gas permeable medium. This medium comprises at least one polyfluorinated compound. This compound may be gassed, for example with oxygen where oxygenation is required.

Abstract: A matrix for tissue culture comprising two kinds of sponges having at least one different physical property and/or at least one different chemical property; a method for culturing tissue using said matrix for tissue culture comprising inoculating and culturing first cell on a first sponge, laminating a second sponge thereon, and inoculating and culturing second cell on said second sponge; a method for fixing a cultured tissue comprising placing a cultured tissue in gelatin solution solated by elevating temperature, lowering temperature to gelatinize gelatin to fix the cultured tissue by said gelatinated gelatin; and an artificial skin fixed comprising dermis layer fixed by gelatin and epidermis layer laminated on the dermis layer.

Abstract: The present invention provides a method for producing an expanded non-transformed cell culture of human liver cells comprising the steps of: (1) preparing partially purified, minced human liver tissue, (2) concentrating the resulting cells and tissue pieces, (3) resuspending the concentrated tissue cells and pieces in a growth medium, (4) culturing the resuspended cells in the growth medium for a time and under conditions to effect sustained cell division, and (5) passaging the cultured human liver cells periodically to expand the culture. The growth medium comprises a combination of a basal medium and ingredients to provide a medium in which the cultured human liver cells are selectively proliferated without being transformed, providing an expanded culture of proliferated, functionally differentiated human liver cells that is substantially free of fibroblast, macrophage and capillary endothelial cells.

Abstract: A method and apparatus for forming a permanent, composite skin replacement consisting of an epidermal component and a porous, resorbable, biosynthetic laminated dermal membrane component for use in wound repair. The dermal membrane is formed in the apparatus, which permits regulation of variables affecting membrane structure. The dermal membrane may be modified to incorporate biologically active molecules to enhance wound repair and to reduce infection when the skin replacement is applied to a wound.

Abstract: Haematopoietic stem cells (which term includes early progenitor cells) are immobilized on a substrate coated with a fibrin matrix and including a substance capable of both binding to the fibrin matrix and also having an RGD amino acid sequence for binding to the stem cells. The substance may be fibronectin or thrombospondin. The substrate is generally in the form of a closed bag formed of a carbon dioxide-permeable and oxygen-permeable plastics material which allows culturing of the stem cells. The cultured stem cells may re-engraft a patient following chemotherapy or to correct haemotological deficiencies. Stem cells may be harvested from peripheral blood onto the coated substrate. The stem cells in contact with the coated substrate are good candidates for gene therapy to introduce a heterologous gene e.g. employing a transfection vector.

Abstract: Disclosed are a composition of chemically defined components which support the in vitro chondrogenesis of mesenchymal progenitor cells, a method for in vitro chondrogenic induction of such progenitor cells and a method of forming human chondrocytes in vitro from such progenitor cells.

Abstract: The invention relates to an implant obtained by assembling in vitro various elements in order to form a neo-organ which is introduced preferably in the peritoneal cavity of the recipient. The implant comprises a biocompatible support intended to the biological anchoring of cells; cells having the capacity of expressing and secreting naturally or after recombination a predetermined compound, for example a compound having a therapeutical interest; and a constituent capable of inducing and/or promoting the gelling of said cells. The invention also relates to a kit for the preparation of the implant as well as to a new recombinant retroviral vector comprising a provirus DNA sequence modified in that the genes gag, pol and env have been deleted at least partially so as to obtain a proviral DNA capable of replication. The invention also relates to recombinant cells comprising the new retroviral vector.

Abstract: A supported polyionic hydrogel is prepared by impregnating a support matel with a solution of anionic polysaccharide and a solution of cationic polysaccharide where the anionic polysaccharide and cationic polysaccharide react with each other to form a polyionic hydrogel impregnated in the support material. The hydrogel may be dried such as by lyophilization. Preferably, the anionic polysaccharide is xanthan, dicarboxystarch or dicarboxycellulose and the cationic polysaccharide is chitosan. Especially preferred is a polyionic hydrogel formed from xanthan and chitosan. A paper material or a textile material can be used as the support material. A dry supported polyionic hydrogel can be formed as a bandage without active material incorporated therein. The supported polyionic hydrogel may be formed containing a biologically active material by having the active material in either polysaccharide solution or in another solution impregnated into the support material.

Abstract: The present invention relates to a three-dimensional cell and tissue culture system. In particular, it relates to this culture system for the long term culture of liver cells and tissues in vitro in an environment that more closely approximates that found in vivo. The culture system described herein provides for proliferation and appropriate liver cell maturation to form structures analogous to tissue counterparts in vivo. The resulting liver tissues survive for prolonged periods, perform liver-specific functions, and maintain hepatic tissue architecture following in vivo implantation.The liver cultures have a variety of applications ranging from transplantation or implantation in vivo, to screening cytotoxic compounds and pharmaceutical compounds in vitro, to the production of biologically active molecules in "bioreactors" and to the construction of extracorporeal liver assist device.

Abstract: A bioartificial three-dimensional hydrogel extracellular matrix derivatized with a cell adhesive peptide fragment is provided for use in tissue regeneration or replacement. The choice of adhesive peptide fragment depends on the desired target cell type. Cartilage or tendon can be regenerated by implanting a matrix containing adhesive peptide fragments that favor chondrocyte invasion. The matrix can be pre-seeded with cells, and tissue can be reconstituted in vitro and then implanted. A cell-seeded matrix can be encapsulated in a semi-permeable membrane to form a bioartificial organ. An agarose hydrogel matrix having an agarose concentration of 0.5-1.25% (w/v) and an average gel pore radius between 120 nm and 290 nm is preferred. The peptide fragment preferably contains the sequence, ArgGlyAsp or TyrIleGlySerArg or IleLysValAlaVal, and is covalently immobilized to the matrix.

Abstract: The invention features a method for the selection and expansion of bone marrow stromal cells. The method includes the steps of obtaining bone marrow stromal cells; introducing the stromal cells into a vessel pre-coated on an inner surface with a gelatin, and containing a culture medium including an acidic fibroblast growth factor ("aFGF") polypeptide; and expanding the stromal cells in the culture medium under conditions and for a time sufficient to obtain an increased number of bone marrow stromal cells. The culture medium additionally can include heparin, and the vessel additionally can be precoated with fetal bovine serum.

Abstract: A composition and method are provided for inhibition of vascular smooth muscle cell proliferation following injury to the endothelial cell lining of a blood vessel such as resulting from angioplasty, vascular bypass surgery or organ transplantation. The composition is a matrix such as a biodegradable hydrogel made of a synthetic polymer, protein or polysaccharide seeded with vascular endothelial cells which can be xenografts, allografts or autografts, or genetically engineered cells. Attachment of cells to the matrix can be enhanced by coating with collagen, laminin, fibronectin, fibrin, basement membrane components or attachment peptides. Biologically active compounds such as anti-inflammatory agents may also be contained in the matrix. In the method, the matrix containing endothelial cells is implanted in a patient at a site adjacent the injury such as by wrapping the matrix around the blood vessel.

Abstract: Provided are methods and compositions for the repair of articular cartilage defects in a mammal. Denuded chondrogenic cells are proliferated ex vivo as monolayer cultures in order to expand the pool of available chondrogenic cells. During proliferation the chondrogenic cells stop secreting the extracellular matrix components, type II collagen and sulfated proteoglycans. The proliferated cells then are seeded into a pre-shaped well having a cell contacting, cell abhesive surface. The cells cultured in the well redifferentiate and begin to secrete cartilage-specific extracellular matrix again. Accordingly, essentially unlimited amounts of synthetic cartilage may be prepared from small samples of biopsy tissue. Also provided are methods for surgically repairing articular cartilage defects in mammals using the synthetic cartilage prepared in accordance with the invention.

Abstract: A cell-polymeric solution is injected into an animal where the polymer crosslinks to form a polymeric hydrogel containing dispersed cells and the cells form new tissue in the animal. The polymer is biodegradable and is a natural polymer such as alginate or a synthetic polymer. The cells are chondrocytes, osteoblasts, muscle cells, fibroblasts or cells acting primarily to synthesize, secret or metabolize materials. Crosslinking of the polymer results from using cations or anions, altering the pH or changing the temperature. A polyion such as polyethyleneimine or polylysine can be added before injection to stabilize the polymeric hydrogel. A kit for tissue formation is provided by combining the cell-polymeric solution with a means for injecting the solution into an animal.

Abstract: A supported polyionic hydrogel containing biologically active material is epared by impregnating into a porous support material a solution of anionic polysaccharide, a solution of cationic polysaccharide and a biologically active material. The anionic polysaccharide and the cationic polysaccharide react with each other to form a hydrogel containing the biologically active material. The hydrogel may be dried such as by lyophilization. The biologically active material can be in either polysaccharide solution or in another solution impregnated into the porous support material. A paper material or a textile material may be used as the porous support material. Preferably, the anionic polysaccharide is xanthan, dicarboxystarch or dicarboxycellulose and the cationic polysaccharide is chitosan. Especially preferred is a hydrogel formed from xanthan and chitosan.

Abstract: The present invention provides a method for producing an expanded non-transformed cell culture comprising the steps of: (1) preparing partially purified, minced tissue; (2) concentrating the resulting cells and tissue pieces; (3) resuspending the concentrated tissue cells and pieces in a culture medium capable of supporting sustained cell division that is contained in a culture vessel; (4) incubating the cells; and (5) passaging the cells periodically. The present invention further provides clonal strains of cells derived from the above-mentioned cell culture, medium and conditioned medium designed for the culturing of such cells, including pancreatic, thyroid, parathyroid, and parotid cells, and the use of cultured pancreatic cells to form pancreatic pseudotissues composed of matrix-embedded aggregated (pseudoislets) or individual cells, to treat blood sugar disorders in mammals, and to test for cytotoxicity and autoimmune activities with reference to pancreatic endocrine cells.

Abstract: A method for maintaining hepatocytes in culture includes providing the hepatocytes with a support, the support including extracellular matrix, the support having a configuration that permits each of at least a portion of the hepatocytes to form at least one apical surface and at least two discrete basal surfaces.