Abstract: A material for suppressing proliferation of cancer cells is produced by entrapping cancer cells in a selectively-permeable structure such as a bead, and culturing the entrapped cells in a culture medium. Entrapment restricts growth of the cancel cells during culturing and causes the cells to produce in the culture medium a material having a molecular weight of at least about 30 kd as measured by filtration that suppresses proliferation of cancer cells. The material is separated from the culture medium by filtering the medium through a filter that separates material having a molecular weight of at least about 30 kd from material having a molecular weight of less than 30 kd. The structure that entraps the cells may contain 10,000 to 500,000 cells. The material or the structure containing the entrapped cells that produce the material can be administered to a subject to suppress cancer cell proliferation.

Abstract: Cells, preferably isolated pancreatic islet cells, are treated with a compound or a combination of compounds selected from an antioxidant, an anti-cytokine, an anti-endotoxin and an antibiotic. The compound or combination of compounds is in a medium for culturing the cells before microencapsulation, in a medium for cryopreserving the cells by freezing followed by thawing and microencapsulation, in a medium for culturing the cells after microencapsulation, or in a medium for culturing the cells before microencapsulation and in a medium for culturing the cells after microencapsulation. In a preferred method, isolated pancreatic islet cells are cultured for about 12 to about 36 hours in a medium containing an antioxidant as the compound, cryopreserved by freezing in a medium containing the compound or combination of compounds, thawed and microencapsulated. The microcapsule contains a hydrogel core such gelled alginate and a semipermeable outer membrane such as formed with polylysine.

Abstract: A device that includes a living cell or tissue and an agent that inhibits the ability of a host molecule to damage the cell or tissue. The device can be constructed in various forms including an implantable device, a composite microreactor and a double composite microreactor. The composite microreactor includes an internal particle that includes a living cell or tissue, an internal particle matrix that includes the living cell or tissue and an internal semipermeable coating enclosing the internal particle matrix, a gel super matrix in which the internal particle is embedded, and an agent that inhibits the ability of a host molecule to damage the cell or tissue. The double composite microreactor includes an internal particle, a particle that includes a particle matrix in which the internal particle is embedded, a super matrix in which the particle is embedded, and an agent that inhibits the ability of a host molecule to damage the living cell or tissue.

Abstract: An angiogenic material is provided which promotes extensive vascularization when implanted in animal tissue. The angiogenic material contains a biocompatible polymer and a vascularizing polymerizable compound capable of forming anions. The polymer may be a polyacrylate, and the polymerizable compound includes compounds having ionizable groups selected from sulfates, sulfonic acid groups and carboxyl groups. These compounds include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, vinylsulfonic acid and vinylacetic acid. The angiogenic material is preferably used in microcapsule coatings and microspheres for implantation in animals. In microcapsules, the angiogenic material promotes better exchange of nutrients, waste products and cellular products between encapsulated cells and the circulatory system of the host animal.

Abstract: Microparticles such as propagules of eukaryotic biocontrol agents are encapsulated in cellular-scale polymer capsules that have a diameter similar to normal eukaryotic cells in a range of about 10 &mgr;m to about 400 &mgr;m. The microparticles are encapsulated by adding a hydrophobic dispersion medium such as a mixture of chloroform and hexane or a mixture of corn oil and n-hexadecane having a specific gravity of about 1 and containing an emulsifier such as lecithin to an aqueous suspension of the microparticles and a polymer matrix precursor such as alginate, agitating vigorously to form a stable emulsion of microscopic globules containing a microparticle, and adding the emulsion to an aqueous solution containing a polymerizing agent such as calcium chloride to polymerize and precipitate the globules to form microparticles encapsulated in polymer matrix capsules that may be of a teardrop shape having a length of 40-200% longer than the diameter.

Abstract: Cartilage tissue and implants comprising cartilage tissue are produced in vitro starting from cells having the ability to form an extracellular cartilage matrix. Such cells are brought into a cell space (1) and are left in this cell space for producing an extracellular cartilage matrix. The cells are brought into the cell space to have a cell density of ca. 5×107 to 109 cells per cm3 of cell space. The cell space (1) is at least partly separated from a culture medium space (2) surrounding the cell space by a semi-permeable wall (3) or by an open-pore wall acting as convection barrier. The open-pore wall can be designed as a plate (7) made of a bone substitute material and constituting the bottom of the cell space (1).

Abstract: A material for suppressing proliferation of cancer cells is produced by entrapping cancer cells in a selectively-permeable structure such as a bead, and culturing the entrapped cells in a culture medium. Entrapment restricts growth of the cancel cells during culturing and causes the cells to produce in the culture medium a material having a molecular weight of at least about 30 kd that suppresses proliferation of cancer cells. The material is separated from the culture medium by filtering the medium through a filter that separates material having a molecular weight of at least about 30 kd from material having a molecular weight of less than 30 kd. The structure that entraps the cells may contain 10,000 to 500,000 cells.

Abstract: A suspension of animal cells is incubated with supports to adhere the cells to the supports. Preferably, the supports have pores that provide pore volume, and the cells are grown during incubation until most of the available pore volume is filled with cells. An encapsulating layer is then formed around the supported cells by exposing the cells on the supports to a reactive gas composed of a carrier gas such as sterile air saturated with an inorganic alkoxide followed by treatment with steam to hydrolyze residual alkoxide groups. The encapsulated cells are stored by immersion in culture media. The cells may be in the form of cell aggregates, and the supports can be sterilized. The supports and encapsulating layer can have pores of a size that permit free exchange nutrients and metabolic products, and excludes the cells from contacting antibodies or immune cells when implanted. The encapsulated cells can used in an extracorporeal device or implanted directly.

Abstract: Tissue-equivalent and biopolymer tubes include fibrils which are oriented by a magnetic field. These oriented fibrils provide enhanced mechanical properties to the tissue-equivalent and biopolymer tubes. One such tissue-equivalent tube includes a body of collagen with mammalian tissue cells interspersed therein. The collagen fibrils are circumferentially oriented within the tubular body by a magnetic field, thereby inducing circumferential orientation of the cells. Methods of making magnetically oriented tissue-equivalent tubes and biopolymer tubes are also disclosed.

Abstract: Encapsulated viable cells for implanting are prepared having cells dispersed in a particulate, essentially non cross-linked chitosan core matrix that is enclosed within a semipermeable membrane. The cells are entrapped between chitosan particles of the core matrix and there is essentially no interfacial cross-linking between the core matrix and the membrane. The core matrix provides a physical support for the cells such that the cells are evenly dispersed throughout the core matrix so as to allow their maintenance, growth, proliferation and differentiation. The encapsulated cells may be prepared by mixing viable cells with a solution of chitosan, encapsulating the resultant mixture in a thermoplastic semipermeable membrane, and causing the chitosan to precipitate such as by changing the pH to form the core matrix. Alternatively, the chitosan in solution is precipitated to form the core matrix containing cells, and the core matrix is encapsulated in a semipermeable membrane.

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 method of obtaining a blood-cell fraction enriched for potent antigen presenting cells is disclosed. The method includes obtaining a monocyte-depleted lymphocyte fraction, culturing the cell fraction in a serum-free medium for a period sufficient to produce a morphological change in dendritic-precursor cells to cells having the morphology of dendritic cells, harvesting non-adherent cells produced by said culturing, and enriching the portion of dendritic cells in the harvested cells by density centrifugation. Also disclosed is a PAP cell composition containing cells enriched for PAP activity in a collagen matrix.

Abstract: There is provided a method for growing human intervertebral cells. Disc tissue is surgically removed from a normal disc of a patient, the cells expanded by feeding with a cell stimulant such as a growth factor, or a cytokine or a bioactive agent to form monolayer primary cell cultures on a plastic mesh such as a nylon mesh. In the case of a growth factor, fetal bovine serum is preferred as it improves cell proliferation and production of appropriate extracellular matrix components. In another aspect of this invention, the monolayer primary cell cultures are seeded in alginate or agarose and fed again with the cell stimulant until three-dimensional cell cultures are formed. The cells are recovered from the alginate or agarose or from monolayer cultures. Re-implantation is carried out using bioresorbable carriers or cell suspensions.

Abstract: The present invention generally relates to novel encapsulation compositions and methods. In particular, the invention relates to stabilized microcapsule compositions which comprise a layer of a crosslinked, mixed functionality, polymer matrix, and methods for their preparation. The encapsulated compositions may comprise the crosslinked polymer matrix layer as an inner layer, an outer layer, or an intermediate layer of an overall encapsulated composition. The compositions will generally also comprise a biological material, e.g., cells, proteins, and the like, encapsulated within the composition. The compositions and methods of the invention are useful in a variety of applications, including cell culturing and transplant therapy.

Abstract: A "micro" hollow fiber bioreactor and method of use are provided for use in screening different cell lines and process conditions. The bioreactor includes the use of an oxygen permeable (e.g., silicone rubber) tube sealably containing a hollow fiber bundle, in order to create an extracapillary space to provide a medium reservoir and an intracapillary space for the growth of cells. The bioreactor avoids the need for oxygen or medium pumps or supply systems, and permits multiple cell lines, and/or multiple conditions to be evaluated simultaneously. Preferably, the tube has an oxygen permeability of between about 100.times.10.sup.-10 to about 10,000.times.10.sup.-10 (cc-mm/sec-cm.sup.2 -cm Hg), the extracapillary space provides a medium reservoir of about 1 ml to about 100 ml, the intracapillary space provides a cell culture volume of about 0.1 ml to about 1 ml, the hollow fibers have a molecular weight cut off from about 1 kD to about 1,000 kD and a pore size of from about 0.

Abstract: Cell encapsulating devices capable of maintaining large numbers of viable cells are provided containing an inert, substantially cell-free core that displaces cells, a permeable membrane and a zone for maintaining cells. The permeable membrane surrounds the core such that the zone of cells is bounded by the core and the permeable membrane. The cell zone may contain a support means for cell attachment and the core may have an outer boundary containing a material that promotes cell adhesion. Preferably, the cell zone has a thickness such that at least about 10% of the cells, more preferably at least about 50% or 80%, in a cell layer located closest to the outer boundary of the core remain viable. The thickness is preferably less than 500 microns such as 25 to 250 microns or 50 to 100 microns. The devices are suitable for implantation into an individual in need of treatment and are capable of supplying therapeutic substances to such individuals.

Abstract: Methods of maintaining animal cells for product production, for supporting hepatocyte function and viability to treat a patient suffering from hepatic failure and for preserving tissue-specific function of mammalian cells are carried out with a bioreactor containing a feed and waste chamber and a cell chamber separated by a selectively permeable membrane. Within the cell chamber, a biocompatible contracted three-dimensional gel matrix entraps animal cells or genetic modifications thereof, and a liquid phase contains a concentrated solution of the cell product. The bioreactor uses only two chambers to achieve three distinct zones within the bioreactor. The bioreactor can be of either hollow fiber or flat-bed configuration. In the configuration using hollow fibers, the two fluid paths correspond to the cavity surrounding the hollow fibers (the extracapillary space), and to the lumens of the hollow fibers themselves. Both fluid paths have inlet and outlet ports.

Abstract: Devices and methods for enhancing the healing of wounds, especially chronic wounds (e.g., diabetic wounds), are provided involving the use of keratinocytes. Keratinocytes are grown on a transplantable solid support (e.g., collagen-coated beads), and the keratinocyte-coated solid support is placed in an enclosure. The enclosure, in turn, is placed in the wound for use as an interactive wound healing promoter. After the enclosure is placed in a wound, the wound may be covered with a dressing. The enclosure is degradable or non-degradable, and is constructed from a membrane or a porous polyester mesh material having pores that are either too small or large enough for keratinocytes to cross. A means may be attached to the enclosure to enable removing the enclosure from a wound.

Abstract: An implantable device having a body of matrix material made up of insoluble collagen fibrils, and disposed therewithin(a) a plurality of vertebrate cells; and(b) a plurality of microspheres each of which consists primarily of one or more of the following materials: collagen, polystyrene, dextran, polyacrylamide, cellulose, calcium alginate, latex, polysulfone, or glass.

Abstract: A sealed, implantable, encapsulation device (20) for diffusing a biologically active product or function to an individual which includes a substantially non-porous fitting (32) including an inner surface (33) defining an access port (34). A permselective, porous, membrane (21), having an interior surface (22), cooperates with the fitting inner surface (33) to form a storage cavity (23) therebetween. The membrane interior surface (22) is in substantially cell-tight dry sealing engagement with fitting (32) to seal cavity (23). Living cells (24) are disposed in the cavity (23) which are capable of secreting the biologically active product to an individual. The membrane (21) is of a material capable of permitting the passage of substances between the individual and cells required to provide the biological product or function. A plug member (35) is positioned in the access port (34) and seated in cell-tight sealing engagement with the fitting inner surface (33).

Abstract: The invention relates to new artificial tissues which comprise three-dimensional extracellular matrixes (ECM) in cross-linkable structures, cell interaction systems for inducing artificial three-dimensional tissues and which comprise genetically manipulated cells releasing immunosuppressive or cell-differentiating factors. The tissues according to the invention are suitable for producing vital transplants and for establishing models of diseases.

Abstract: The invention covers a method of implanting a living donor cell into a host animal without inflammatory response or rejection of the donor cell by the host animal, by obtaining an uncoated particle of a biocompatible, temperature-independent gel that encapsulates the living donor cell, wherein the uncoated particle provides a molecular weight cutoff that prevents host animal immune cells from entering the particle, yet does not have to prevent entry of host animal IgG and complement into the particle, and implanting the uncoated particle into the host animal.

Abstract: The present invention is directed to a non-immunogenic cellular composition comprising: a cell having a cell surface and antigenic determinants on the cell surface; a linker molecule covalently attached to the cell surface; and a non-immunogenic compound (e.g., polyethylene glycol or derivative thereof) covalently attached to the linker molecule. In one embodiment, the linker molecule is covalently attached directly to the antigenic determinant on the cell surface. In an alternate embodiment, the linker molecule may be covalently attached to a non-antigenic site on the cell surface, but will camouflage the antigenic determinant on the cell surface by virtue of the long chain length of the non-immunogenic compound.

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: The present invention is directed to a cell encapsulation device that permits rapid and straightforward cell transfer into the device. The preferred device includes components that allow a user to quickly transfer cells into the device with minimal risk to the cells. Among the most important improvements of the present invention are: automatic filtration of excess solution during cell transfer; an instantly wettable cover, allowing ready view into the cell chamber; and a swellable core, allowing cells to be transferred with minimal shear force while assuring optimal cell placement in the device during use. The device of the present invention may be used either in vivo, such as to deliver therapeutic substances, or in vitro, such as to serve as a bioreactor.

Abstract: Living tissue cells such as from an animal or a plant are encapsulated in inorganic microspheres. An organosilicon precursor such as tetraethoxysilane or an organometallic precursor such as aluminum tri-n-propoxide is hydrolyzed in an aqueous acidic solution to form a gel forming solution. Tissue cells are mixed with a salt solution such as Hanks' Balanced Salt Solution to form a solution containing the tissue cells. The solution containing tissue cells and the gel forming solution are mixed to form a mixture. The mixture is mixed with an oil that is immiscible with the mixture and has a lower specific density than the mixture. The resultant mixture is stirred to form microspheres encapsulating the tissue cells. The mixture containing the tissue cells and the gel forming solution may be formed into droplets and added to the top of a column containing the oil to form the microspheres.

Abstract: In a process for producing an implant from cell cultures in vitro, tissue cells, particularly cartilage cells, are introduced into a three-dimensional self-supporting structure preformed preferably from nonwoven polymer material, the supporting structure having a shape corresponding to that of the desired implant. The supporting structure is then perfused with a nourishing solution for a sufficiently long period of time that an intercellular matrix which bonds the cells together is formed at least partially within the supporting structure. The supporting structure with the at least partially formed intercellular matrix may then be implanted. Upon subsequent resorption of the supporting structure, the shape of the implant is maintained and preserved by the intercellular matrix then formed.

Abstract: Implantable beads which contain agarose and optionally collagen, and are coated with agarose have incorporated within cells which produce diffusible biological products. The beads may be used as implants to modulate a recipient's immune response. The beads may also be used in an in vitro context to encourage specific types of cells to grow, to produce desirable products in culture, or to suppress growth of certain cells. The implants may also suppress growth of certain cells following administration to a subject. Cancer cells such as renal cancer cells when restricted by being entrapped in the beads produce more of a material that suppresses cancer cell proliferation.

Abstract: The present invention provides a method for producing an expanded, enriched, non-transformed human cell culture of human pancreatic, thyroid or parathyroid endocrine cells and other types of cells which comprises (1) preparing partially purified, minced tissue that includes a desired type of cells; (2) concentrating the desired cells; (3) resuspending the concentrated cells in a growth medium which selects in favor of the desired cells and in which those cells are proliferated without being transformed and differentiated functions are retained through periodic passaging; (4) culturing the resuspended cells in the growth medium to effect sustained cell division; and (5) passaging the cultured cells periodically to expand the culture.

Abstract: A method of adding or removing a gas to or from a solution of the gas in a liquid involves transferring the gas between the liquid and another fluid through a membrane unit. The membrane unit includes a membrane which is (i) substantially impermeable to the solvent and having a permeability to oxygen of at least 100 barrers; (ii) formed from an amorphous copolymer of perfluoro-2,2-dimethyl-1,3-dioxole; and (iii) is maintained at a temperature below the glass transition temperature of the copolymer. The fluid can be another liquid or a gas. The novel method provides very high rates of gas transmission between liquids and permits gasifying liquids without resort to sparging bubbles through the liquid. The method thus can gasify liquid with superior efficiency and without excessive agitation due to bubbling.

Abstract: Vehicles containing cells for implanting in the tissue of an individual are prepared having cells dispersed in a particulate, essentially non cross-linked chitosan core matrix that is enclosed within a semipermeable membrane. The cells are entrapped between chitosan particles of the core matrix and there is essentially no interfacial cross-linking between the core matrix and the membrane. The core matrix provides a physical support for viable cells within the vehicle such that the cells are evenly dispersed throughout the core matrix so as to allow their maintenance, growth, proliferation and differentiation. The vehicle can be prepared by mixing viable cells with a solution of chitosan, encapsulating the resultant mixture in a semipermeable membrane and causing the chitosan to precipitate such as by changing the pH to form the core matrix. Alternatively, the chitosan is precipitated to form the core matrix containing cells and then the core matrix is encapsulated in a semipermeable membrane.

Abstract: Methods and compositions are provided for controlling cell distribution within an implantable bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the bioartificial organ with extracellular matrix molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination. The bioartificial organ typically has a semipermeable membrane encapsulating a cell-containing core, and is preferably immunoisolatory.

Abstract: This invention relates to methods and compositions of controlling cell distribution within a bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the BAO with ECM molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination.

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 parotid cells and other glandular cells such as pancreatic, thyroid, and parathyroid, and 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: Methods and compositions are provided for controlling cell distribution within an implantable bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the bioartificial organ with extracellular matrix molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination.

Abstract: A bioartificial organ for implanting to provide a therapeutic effect is prepared containing a core of living cells encapsulated in a foam-like membrane having three regions: a dense, fine-pored, permselective inner region, a middle region that lacks macrovoids and a fine-pored outer region. The membrane has a molecular weight cutoff that permits passage to nutrients to the cells but not passage of the cells. Preferably, the membrane is made of polyether sulfone, pores range in size between 0.02 .mu.m and 2.0 .mu.m and have polyhedrally symmetric boundaries and are arranged asymmetrically from one surface to the other. The membrane has an asymmetry factor AF relative to the maximum pore diameter of 0.01 to 2.0 and a ratio of the maximum mean free path length to the diameter of the largest pore of greater than 3. The membrane can be hydrophobic or hydrophilic. The bioartificial organ is formed by coextrusion or by stepwise assembly by forming the cell core and then applying the membrane.

Abstract: The present invention provides methods and a device for producing minimal volume capsules containing viable cells or cellular aggregates. The methods and device use a two-phase aqueous emulsion system to form a dispersion of liquid capsule-forming materials in a continuous liquid phase to which is added a suspension of biological material. Alternatively, the biological material can be added to one or the other of the liquid phases. The composition of this emulsion is adjusted to promote the thermodynamically-driven process of particle engulfment by the dispersed droplets of liquid capsule-forming materials. Subsequently, the droplets engulf the biological material to form a liquid film surrounding the tissue and are converted to solid form, resulting in encapsulation of the biological material in minimum volume capsules.

Abstract: In vitro production of clinically useful quantities of single species of mature, differentiated human blood cells is carried out by a method in which human pluripotent hematopoietic stem cells, preferably from a universal donor, are incubated in a bioreactor in a growth medium also containing specific combinations of recombinant human growth and maturation promoting polypeptide factors that expand stem cell cultures and promote the maturation and differentiation of stem cells into single species of erythroid, thrombocytic or granulocytic human blood cells, and harvesting the mature cells. The growth and maturation promoting polypeptides employed include SCGF, Interleukins 1,3,4,5,6, and 11, GM-CSF, M-CSF, G-CSF and EPO. Stem cells may be preliminarily genetically modified so as to remove histocompatibility or blood group antigens with which a recipient may be incompatible, or the stem cells may be genetically altered by transfection with appropriate DNA-containing vectors, prior to addition to the bioreactor.

Abstract: Methods and compositions are provided for controlling cell distribution within a bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the bioartificial organ with extracellular matrix molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination.

Abstract: A core material such as animal tissue or cells is contained within a semipermeable vessel which may be a microcapsule, hollow fiber or plastic membrane having a semipermeable wall by a method that prevents the core material from incorporation into the wall of the vessel. This is accomplished by suspending the core material in a solution of polysaccharide gum such as an alkali metal alginate in an amount between about 0.2% and about 0.5%, removing and washing the core material to remove all but a thin layer of polysaccharide gum, and gelling the polysaccharide gum with multivalent cations or other means to form a pretreated core material.

Abstract: The present disclosure relates to the application of genetic engineering to provide artificial .beta. cells, i.e. cells which can secrete insulin in response to glucose. This is achieved preferably through the introduction of one or more genes selected from the insulin gene, glucokinase gene, and glucose transporter gene, so as to provide an engineered cell having all three of these genes in a biologically functional and responsive configuration. Assays for detecting the presence of diabetes-associated antibodies in biological samples using these and other engineered cells expressing diabetes-associated epitopes are described. Also disclosed are methods for the large-scale production of insulin by perfusing artificial .beta. cells, grown in liquid culture, with glucose-containing buffers.

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 biocompatible capsule for containing cells for implantation is prepared containing an inner support that provides tensile strength to the capsule. Cells within the capsule are suspended in a liquid medium or immobilized in a hydrogel or extracellular matrix material, and are surrounded by a semipermeable membrane across which biologically active molecules can be delivered from the capsule to surroundings or from the surroundings into the capsule. The inner support may be formed as an integral part of the capsule during a coextrusion process to form the capsule. Alternatively, the inner support may be a discrete component within a tube having top and bottom sealing fittings that are linked withing the tube by the support. The inner support may have external features such as flutes or a roughened or irregularly-shaped surface, and may be coated with cell-adhesive substance or a cell-viability-enhancing substance.

Abstract: A reaction chamber is constructed of a reactant-containing aqueous solution, which may be in droplet form, coated with a fluoropolymer powder such as Polytetrafluoroethylene (PTFE), preferably having a particle size of less than 500 microns. After a reaction, the droplet is destroyed by adding a substance such as a detergent or organic solvent, and the fluoropolymer powder is removed by centrifuging and filtering. Using a micropipette, size of the droplet chamber is increased or decreased by removing or adding liquid, or liquid is transferred from one droplet chamber to another. Charcoal, metal powder or silica powder can be inserted inside or on the surface of the droplet. A droplet chamber containing a first reactant such as an enzyme-bound bead is combined with a second droplet chamber containing a second reactant to react the first and second reactants. A dialysis chamber contains a filtration membrane in contact with the droplet chamber.

Abstract: A method is provided for immobilization of whole microbial cells containing enzymes in Ca-alginate capsules. Whole microbial cells are mixed with a CaCl.sub.2 solution, a small amount of xanthan gum is added, the resultant mixture is added drop-wise while stirring to a Na-alginate solution containing a small amount of surfactant which is preferably polyoxyethylenesorbitan monolaurate to obtain the capsules containing the cells. The capsules may be washed with distilled water, hardened by in a CaCl.sub.2 solution and incubated in a growth medium. The microbial cells are bacteria or fungi cells and may be recombinant cells.

Abstract: Cells for implantation into a patient are packaged within a barrier of immunoprotective tissue prior to implantation to obviate or minimize rejection of the cells. The preferred immunoprotective tissue for forming the barrier is cartilage. The tissue is formed into a layer that is thin enough to allow diffusion of nutrients and gases into the center of a cell mass packaged within the immunoprotective tissue. Typically the layer is less than 300 microns, preferably between 5 and 20 microns. Cells to be implanted, typically dissociated parenchymal cells including hepatocytes, Islets of Langerhans, or other cells having metabolic functions, are then placed on the tissue layer, and the layer is folded to seal the cells to be implanted within the tissue layer. In the preferred embodiment, the dissociated cells are first seeded onto a polymeric fiber matrix.

Abstract: Living animal tissue cells and microbial cells such as yeast cells are encapsulated in an inorganic gel prepared from an organosilicon. Encapsulation of tissue cells is performed by mixing an organosilicon precursor with a highly acidic aqueous solution to hydrolyze the organosilicon precursor and provide a gel forming solution, cooling the gel forming solution, forming a mixture of living tissue cells and Hank's balanced salt solution, adding a base solution to the gel forming solution, immediately thereafter adding the mixture containing tissue cells to the gel forming solution, and pouring the resultant mixture into a container where an inorganic gel forms encapsulating the tissue cells. The organosilicon precursor may be tetraethoxysilane, tetrabutoxysilane, tetramethoxysilane or tetrapropoxysilane.

Abstract: Animal cells are cultured while embedded in a collagen gel. The gel containing cells is formed by dispersing animal cells in a collagen solution, placing a drop (or drops) of the cell-containing collagen solution on a support surface and allowing the drop to gel to fix on the surface as a globular collagen gel having a convex surface. The cells are cultured by contacting the gel with a culture medium that may be serum-free or contain dextran sulfate. The drop preferably contains about 3 to about 300 microliters of the collagen solution and is about 2 mm or less in height. The cells may be precultured on a support surface having a collagen layer, released from the collagen layer by treatment with collagenase and dispersed in the collagen solution. The cells can be evaluated after culturing by staining such as with neutral red, or with fluorescein diacetate and irradiating, or by photographing cells in the collagen gel.

Abstract: Living tissue cells such as animal or plant tissue cell are encapsulated in an inorganic gel by mixing an organosilicon precursor with an aqueous acidic solution to form a gel forming solution and hydrolyze the organosilicon precursor, cooling the gel forming solution, forming a mixture of living tissue cells and Hank's balanced salt solution, adding a base solution to the gel forming solution to form a mixture, immediately thereafter adding the mixture containing living tissue cells to the mixture containing the gel forming solution, and pouring the resultant mixture into a container where an inorganic gel forms encapsulating the cells. The organosilicon precursor may be tetraethoxysilane, tetrabutoxysilane, tetramethoxysilane or tetrapropoxysilane.

Abstract: A transplant with a core of a viable, physiologically active, cell(s) and a non-fibrogenic coating of alkaline earth metal alginate having a high mannuronate to guluronate molar ratio and free from fibrogenic amounts of fucose, sulfate, phloroglucinol and protein moieties. The coating has a permeability sufficiently low and a thickness sufficiently large to protect the tissue cells from host immunological agents after transplantation, the coating also being sufficiently permeable and thin to permit the diffusion of cell sufficient nutrients and cell products through the coating required for cell viability. The alginate coating can be reacted with polylysine to form a polylysine-alginate complex on the outer surface thereof. The complex can then be reacted with polyaspartic acid to provide a physiologically acceptable negative surface charge.