Abstract: Disclosed are compositions with tethered growth effector molecules, and methods of using these compositions for growing cells and tissues. Growth effector molecules, including growth factors and extracellular matrix molecules, are flexibly tethered to a solid substrate. The compositions can be used either in vitro or in vivo to grow cells and tissues. By tethering the growth factors, they will not diffuse away from the desired location. By making the attachment flexible, the growth effector molecules can more naturally bind to cell surface receptors. A significant feature of these compositions and methods is that they enhance the biological response to the growth factors. The new method also offers other advantages over the traditional methods, in which growth factors are delivered in soluble form: (1) the growth factor is localized to a desired target cell population; (2) significantly less growth factor is needed to exert a biologic response.

Abstract: The present invention relates to magnetic carriers in which microorganisms requiring carriers for their growth in the step of treating wastewater have been immobilized, a process for producing the carriers and a method of treating wastewater. The present invention provides microorganisms-immobilized carriers with a high amount of microorganisms immobilized for use in wastewater treatment, the movement of which is controllable in a treatment chamber by magnetic force. Further the present invention provides a process for producing said carriers easily and a method for treating wastewater efficiently.

Abstract: Oxalate-degrading enzymes and bacteria were encapsulated for both enteric and intraperitoneal administration. We have shown that via alginate microencapsulation of Oxalobacter formigenes, enzymatic activity was retained for several months. A new process was developed which strengthened the aliginate microcapsules and their tolerance to citrate treatment. Much smaller (30-50 .mu.m) aliginate microcapsules were made for injection as means of impantation. For oral administration, multi-encapsulated microspheres of cellulose acetate phthalate in poly-2-vinylpyridine (pKa=3.5) were prepared to protect the enzymes from gastric juices.

Abstract: Improved fermentation activity of microorganisms in a polysaccharide gel such as an alginate gel is obtained after dehydration, staorage and rehydration by soaking the gel containing the microorganisms prior to dehydration in a sugar solution to provide in the gel an amount of sugar of at least 100 g/kg and less than 500 g/kg of gel, preferably less than 300 g/k of gel. The dehydration may be carried out in a fluidized bed or by lyophilization. The gel may be in the form of beads or fibers having a double layer structure formed by an internal layer or core of gel containing the microorganisms and an external lay er or envelope of gel essentially devoid of the microoraganisms. The sugar is preferably xylose, glucose, fructose, lactose or sucrose, and the sugar solution may contain a polyol such as sorbitol, inositol or glycerol to provide in the gel an amount of polyol of at least 30 g/kg of gel.

Abstract: This invention relates to novel salts composed of a cation derived from a peptide containing at least one basic group and an anion derived from a carboxy-terminated polyester, processes for the manufacture of such salts, and the use of such salts in the manufacture of extended release pharmaceutical compositions. The salts of the invention possess a variety of properties which are useful in the formulation of extended release pharmaceutical compositions, whether the salts are in pure form or are in admixture with either an excess of the peptide in its free, unbound form or an excess of the free polyester.

Abstract: Multiple layered functional thin films fixed on a solid support are provided which comprise multiple layers of functional molecules (such as enzymes and other proteins, pigments and dyes) admixed with polymer ions in combination with multiple layers of polymer ions without the functional molecules. The films are prepared by immersing a solid support having an electric charge in an admixed polymer ion-functional molecule solution having a net electric charge opposite to that of the solid support followed by immersing the solid support in a polymer ion solution having a net electric charge opposite to that of the admixed polymer ion-functional molecule solution, and repeating at least once the immersings of the solid support in the solutions.

Abstract: A novel neurotrophic factor referred to as glial cell line-derived neurotrophic factor (GDNF) has been identified and isolated from serum free growth medium of B49 glioblastoma cells. Rat and human genes encoding GDNF have been cloned and sequenced. A gene encoding GDNF has been subcloned into a vector, and the vector has been used to transform a host cell in order to produce biologically active GDNF in a recombinant DNA process. An implantable device containing recombinant GDNF secreting cells encapsulated in a semipermeable membrane may be used to treat nerve damage in patients suffering from disorders such as Parkinson's disease.

Abstract: A lactase-containing preparation is prepared for use by mammals having a lactase deficiency. A dried bacterial culture containing lactase is mixed with a desiccant such as silicon oxide to stabilize water content of the dried culture. A unit dosage of the resultant stabilized dried bacterial culture is encapsulated in an ingestible capsule such as gelatin capsule. The capsule is coated with an enteric polymer, and the coated capsule is treated under vacuum pressure to remove oxygen and moisture. The treated coated capsule has an extended shelf-life at room and elevated temperatures, and provides lactase activity for at least 10 hours after ingestion. The dried bacterial culture may be in freeze dried form. Suitable bacterial cultures are Lactobacillus acidophillus, Lactobacillus bulgaricus and Streptococcus thermophilus.

Abstract: A crosslinkable macromer system that includes two or more polymer-pendent polymerizable groups and one or more polymer-pendent initiator groups. The polymerizable groups and the initiator group(s) can be pendent on the same or different polymeric backbones. The macromer system provides advantages over the use of polymerizable macromers and separate, low molecular weight initiators, including advantages with respect to such properties as nontoxicity, efficiency, and solubility.

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: Resilient openly porous support structures containing silicon are prepared for cell immobilization. A preferred structure is made of porous silicone rubber foam, and cells are adsorbed to the surfaces of pores. The structure may be in the form of a block, sheet, pad, chip, strand, tube or granule. The silicone rubber foam is formed by aerating liquid silicone rubber, and desired porosity and density are provided by controlling aeration of the liquid silicone rubber. The porosity and/or density may also be controlled by incorporating during manufacture of the structure an inert additive such as a metal powder that produces a dense structure. A density may be provided to prevent the structure from floating in a reaction mixture in which the structure is used. Additives may also be used to control surface properties of the structure. The structure is preferably sterilized before use and may be re-used. The structure is re-used without removing cells or is cleaned to remove cells and then re-sterilized.

Abstract: Contact lens are cleaned and disinfected by contacting with an enzyme that functions as a cleaning agent by degrading deposits on the lens, and with an enzyme inhibitor that inhibits remaining enzyme activity and a mild disinfecting agent. If rinsing of the lens is not carried out after cleaning and disinfecting, this procedure prevents eye damage by inhibiting remaining enzyme activity and using a mild disinfectant. Preferred enzymes are proteases such as an acidic aspartic protease, a cysteine protease, a serine protease or a metalloprotease, and preferred enzyme inhibitors function both as an inhibitor and as a mild disinfectant such as chloramine-T, chloramine-B, bacitracin or aryl boronic acids. In a preferred method, the enzyme is subtilisin A and the enzyme inhibitor and disinfectant is chloramine-T.

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: 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: A composite biosorption material is formed of a hydrophilic urethane binder containing immobilized bioactive organisms of at least about one micron in size and having active sites for binding and removing noxious materials such as metal ions from an effluent such as a waste water stream. To form the composite, a prepolymer is prepared by heating polyethylene glycol, having an average molecular weight of about 1000, to over 200.degree. F. up to 350.degree. F., preferably greater than 220.degree. F., and reacting a diisocyanate with the heated polyethylene glycol while mixing to form the prepolymer. After cooling, the prepolymer is mixed with an aqueous slurry containing the organisms such as Datura innoxia cells, and optionally a surfactant and bactericide, in a weight ratio such as 1:1 to 6:1, and the resultant mixture is cured to form the composite material containing a dry weight of the organisms such as about 15% to 90%.

Abstract: A macroencapsulation device for somatic cells using ultrapurified Na alginate and polysulfone hollow fibers of 30 kDa molecular weight cutoff. Ultrapurified Na alginate material is used which has a high `G` content, low endotoxin content, low divalent metal toxins and low protein impurities. Islet cells prior to being encapsulated, are irrigated with Hank's modified solution (without Ca and Mg) containing gentamycin, vancomycin and amphotericin B and then passed through a leukoabsorb filter to reduce the donor antigen load of passenger leukocytes and to reduce the bioburden of microorganisms including viruses. Encapsulation is done in RPMI 1640 tissue culture fluid containing necessary nutritional supplements and ATP source of energy. The open ends of the fiber are covered with a porous membrane. To further improve biocompatibility, the outer wall of the polysulfone is lightly gelled with alginate gel.

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: A method is provided using centrifugation to prepare a seal of solidified wax, grease or polymer mix over an aqueous reagent in a reaction container such that the reagent is separated from contact with the atmosphere. The amount of solidified wax, grease or polymer mix is not sufficient when melted to a liquid to separate the reagent from contact with the atmosphere under gravity. A reagent and solidified wax, grease or polymer mix are combined in a container. During centrifugation and heating, the solidified wax, grease or polymer mix melts to a liquid, and centrifuging causes the liquid to form over the reagent a layer that completely separates the reagent from the atmosphere. As centrifugation continues, the liquid is cooled and solidified to form the seal. Additional reagents are preferably added on top of the seal such that when the container is heated and the seal melted the upper and lower reagents mix for reaction.

Abstract: L-tertiary-Leucine and L-phosphinothricine are obtainable by transamination of the corresponding keto acids as a precursor in the presence of amino acids as amino group donors. The reaction is preferably carried out with microorganisms or their transaminases.

Abstract: A microorganism holding carrier for a fluidized bed is provided that includes an extruded foamed article having continuous cells and independent cells. The article is composed of a polyolefin resin as a main component. The continuous cells include open-cells which are opened to at least two portions of a surface of the article and a semi-open cell which are opened to only one portion of the surface of the article. A ratio of the total volume of the continuous cells to the total volume of the extruded foamed article (a volume ratio of the continuous cells) falls within a range of from 20% to 70%. Further, a ratio of the total volume of the open-cells to the total volume of the continuous cells (a volume ratio of open-cells) is 20% or more. The article may have an apparent density of 0.90 to 1.80 g/cm.sup.3 and an apparent volume from 2.0.times.10.sup.-3 to 5.0 cm.sup.3, and be in the shape of a column, or a tube having an outer diameter of 2 to 20 mm and a thickness of 5 to 30% of the outer diameter.

Abstract: Enzyme-containing cells are immobilized on a water-insoluble support with a polymer represented by the following general formula (I): ##STR1## wherein Y is a direct bond or a divalent group represented by the following formula (II) ##STR2## R.sub.1 and R.sub.2 are each independently hydrogen atoms or organic residues, X.sup.- represents an anion, and n is an integer of 100 to 5000. The support may be in granular form such as granules of ion exchange resins or inorganic carriers, or in sheet form such as ion exchange films or alumina or silica sheets. Immobilization may be carried out by mixing cells with water and a quaternary salt of polyallylamine as the polymer, and sprinkling the resultant mixture onto the solid support and drying. L-aspartic acid or fumaric acid can be produced by contacting fumaric acid and ammonia, or ammonium fumarate, or maleic acid and ammonia, or ammonium maleate, with immobilized cells containing aspartase or maleate isomerase.

Abstract: A reusable immobilized microbial composition is formulated. The formulated microbial composition comprises a synergistic mixture of the bacterial strains of Enterobacter cloaca, Citrobacter amalonaticus, Pseudomonas aeruginosa,Yersinia enterocolitica, Klebsiella oxytoca, Enterobacter sakazaki and Serratia liquefaciens. The formulated microbial composition is immobilized on an appropriate immobilizing agent to form beads. The said beads are tested as microbial seeding material for BOD analysis using Glucose Glutamic Acid (GGA) as a reference standard. The obtained BOD values by the formulated beads are compared with BOD values obtained by sewage as seeding material using synthetic samples as well as industrial effluents. The formulated microbial beads are ready-to-use as well as reusable seeding material in BOD analysis. The said beads can be reused up to five times with same efficacy.

Abstract: Cells such as hepatocytes are applied to hollow fibers by forming a first gelled matrix layer on the outside surface of the fibers, adhering cells to the matrix layer and forming a second gelled matrix layer covering the adhered cells. To form the matrix layers, a liquid matrix-forming material such as containing collagen is applied and then gelled. An acidic liquid matrix-forming material may be used to prepare the second matrix layer. The hollow fibers may be cooled to less than 15.degree. C. before forming the first gelled matrix layer. Three-dimensional co-cultures may be formed by applying non-parenchyma cells to the inside of the walls of the hollow fibers.

Abstract: A composition containing a protease and glycosidase is provided for removing nits in the treatment of lice infestation. The protease and glycosidase are separated from each other to prevent the protease from hydrolyzing the glycosidase Separation is accomplished by encapsulating either the protease or glycosidase in a lipidic bilayer vesicle while leaving the other outside the vesicle. The protease and glycosidase destroy complex carbohydrate and protein in nit shells, nit embryos and substances secreted by adult lice. In a method of treatment, an infestation site such as hair is treated with a pediculoside and then with the composition containing a protease and glycosidase, and nits are removed such as by washing.

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: Biological components such as enzymes are immobilized in a three-dimensional cross-linked hydrophobic polymer. An enzyme is mixed with an aqueous solvent and a non-crosslinked prepolymer having an essentially nonpolar main chain with attached polar hydrophilic groups and cross-linking groups. The resultant mixture is exposed to cross-linking temperatures to react the prepolymer via the cross-linking groups without additional catalyst or cross-linking agents, and the aqueous solvent is evaporated to form a three-dimensional cross-linked hydrophobic polymer matrix containing the enzyme. The prepolymer can be an oil alkyl resin containing the main chain with attached polar hydrophilic groups and cross-linking groups. The oil alkyl resin is cross-linked by autoxidation, and aqueous solvent is evaporated to form the polymer matrix.

Abstract: Disclosed is a method for collecting DNA by lysing microbial cells, adsorbing released DNA on a carrier and collecting the DNA adsorbed on the carrier, which method comprises the following steps of (1) lysing the microbial cells in the presence of the carrier so that the DNA obtained by lysing cells is adsorbed onto the carrier, separating solutions used for lysing cells and adsorbing DNA from the carrier, and eluting the DNA adsorbed on the carrier with a solution for eluting DNA and collecting eluted DNA, or (2) feeding microbial cells into a column comprising the carrier provided on a membrane filter capable of retaining a solution and permeating the solution when aspirated, lysing the microbial cells in the column so that the DNA obtained by lysing cells is adsorbed onto the carrier, separating solutions used for lysing cells and adsorbing DNA in the previous step from the column by aspiration, and feeding a solution for eluting DNA into the column and aspirating to collect the DNA adsorbed on the carrier

Abstract: Disclosed are compositions with tethered growth effector molecules, and methods of using these compositions for growing cells and tissues. Growth effector molecules, including growth factors and extracellular matrix molecules, are flexibly tethered to a solid substrate. The compositions can be used either in vitro or in vivo to grow cells and tissues. By tethering the growth factors, they will not diffuse away from the desired location. By making the attachment flexible, the growth effector molecules can more naturally bind to cell surface receptors. A significant feature of these compositions and methods is that they enhance the biological response to the growth factors. The new method also offers other advantages over the traditional methods, in which growth factors are delivered in soluble form: (1) the growth factor is localized to a desired target cell population; (2) significantly less growth factor is needed to exert a biologic response.

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: Methods for inhibition of fibrotic rejection of implanted devices which contain cells by administering to the recipient of the devices an amount of a non-steroidal anti-inflammatory agent (NSAID) sufficient to inhibit fibrotic inactivation of the device. Most NSAID's are carboxylic acids (R--COOH) or enolic acids (R--COH).

Abstract: This invention relates to novel salts composed of a cation derived from a peptide containing at least one basic group and an anion derived from a carboxy-terminated polyester, processes for the manufacture of such salts, and the use of such salts in the manufacture of extended release pharmaceutical compositions. The salts of the invention possess a variety of properties which are useful in the formulation of extended release pharmaceutical compositions, whether the salts are in pure form or are in admixture with either an excess of the peptide in its free, unbound form or an excess of the free polyester.

Abstract: Disclosed are improvements for enzyme-catalyzed reactions involving DNA or RNA, including restriction digests, which are based on conducting such reactions in the presence of lipids.

Abstract: The present invention is directed to a method of treating a patient with diabetes by implanting an improved macrocapsule containing living islet cells in the patient. The improved macrocapsules encapsulate microcapsules containing islet cells, to make the system more biocompatible by decreasing the surface area and surface roughness of microencapsulated biological materials; increasing stability of microencapsulated islet cells; enhancing cytoprotectivity by increasing diffusion distance of encapsulated islet cells from cytotoxins secreted in vivo; providing retrievability of microencapsulated material; and providing a system of sustained release of the cellular products.

Abstract: A granular enzyme composition is produced having reduced tendency to form dust and leave a residue, and improved stability and delayed release characteristics. The composition has a core, optionally coated with a vinyl polymer, a layer containing an enzyme and a vinyl polymer and optionally a plasticizer or anti-agglomeration agent, and an outer coating containing a polymer and optionally a low residue pigment and/or lubricant. Preferably, the core is a salt or sugar nonpareil, the vinyl polymer coating the core is polyvinyl alcohol and most preferably partially hydrolyzed polyvinyl alcohol, the vinyl polymer in the enzyme layer is polyvinyl pyrrolidone, and the polymer of the outer coating is polyvinyl pyrrolidone, polyvinyl alcohol which may be partially hydrolyzed, polyethylene glycol or mixtures thereof such as a mixture of polyvinyl pyrrolidone and polyvinyl alcohol or a mixture of polyvinyl pyrrolidone and polyethylene glycol.

Abstract: A biological tissue transplant coated with a stabilized multilayer alginate coating and a method for preparation of the stabilized multilayer coating. Coating has three primary layers of the alginate with a polyamino acid barrier emplaced between a primary and a secondary layer. The secondary "halo" layer of soft gel is formed by a gel gradient created between weakly bound cross-linking gelling divalent cations of an alginate used for the primary layer of the coating and non-gelling counter ions of a non-ionic alginate of the secondary layer of the coating.

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: A process for immobilizing viable cells in gelled carrageenan beads comprises preparing an aqueous phase that is a mixture of a gellable concentration of un-gelled carrageenan, in an aqueous suspension of viable cells, in which the mixture's potassium concentration is low enough that the thermogellation temperature of the carrageenan in the suspension is below a temperature to which the viable cells are substantially thermosensitive. This is done at a first processing temperature that exceeds the thermogellation temperature of the carrageenan in that aqueous suspension, but which is below the temperature to which the cells are substantially thermosensitive. A mixture of the aqueous phase and a non-reactive food-grade oil phase is then prepared, and subjected to shear by passing it through a static mixer under flow-rate conditions selected to disperse the aqueous phase in the oil phase, such that a resulting emulsion has a selected droplet size distribution.

Abstract: Graphitic nanotubes, which include tubular fullerenes (commonly called "buckytubes") and fibrils, which are functionalized by chemical substitution, are used as solid supports in electrogenerated chemiluminescence assays. The graphitic nanotubes are chemically modified with functional group biomolecules prior to use in an assay. Association of electrochemiluminescent ruthenium complexes with the functional group biomolecule-modified nanotubes permits detection of molecules including nucleic acids, antigens, enzymes, and enzyme substrates by multiple formats.

Abstract: A stromal cell-based three-dimensional cell culture system is provided which can be used to culture a variety of different cells and tissues in vitro for prolonged periods of time. The stromal cells along with connective tissue proteins naturally secreted by the stromal cells attach to and substantially envelope a framework composed of a biocompatible non-living material formed into a three-dimensional structure having interstitial spaces bridged by the stromal cells. Living stromal tissue so formed provides support, growth factors, and regulatory factors necessary to sustain long-term active proliferation of cells in culture and/or cultures implanted in vivo. When grown in this three-dimensional system, the proliferating cells mature and segregate properly to form components of adult tissues analogous to counterparts in vivo, which can be utilized in the body as a corrective tissue.

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: 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: Bioartificial implants and methods for their manufacture and use are described, particularly bioartificial pancreases. In particular, the implants may be thin sheets which enclose cells, may be completely biocompatible over extended periods of time and may not induce fibrosis. The high-density-cell-containing thin sheets are preferably completely retrievable, and have dimensions allowing maintenance of optimal tissue viability through rapid diffusion of nutrients and oxygen and also allowing rapid changes in the secretion rate of insulin and/or other bioactive agents in response to changing physiology. Implantations of living cells, tissue, drugs, medicines and/or enzymes, contained in the bioartificial implants may be made to treat and/or prevent disease.

Abstract: A lawn assay is described for determining compounds that affect enzyme activity or that bind to target molecules. Compounds to be screened are cleaved, and diffused from solid supports into a colloidal matrix. Enzymatic catalysis or binding to target molecules by the compounds is carried out in the matrix. Active compounds are found by monitoring a photometrically detectable change in a substrate, coenzyme, or cofactor involved in the enzymatic reaction, or in a labeled ligand bound to the target molecule, that produces a zone of activity associated with the compounds.

Abstract: A structurally stable gel bead containing an entrapped enzyme and a method for its manufacture. The enzyme is covalently cross-linked to gelatin in the presence of glutaraldehyde prior to the formation of the gel bead, to prevent leakage of the enzyme. Propylene glycol alginate is then added to the mixture. Once the gel beads are formed, they are then soaked in glutaraldehyde, which imparts structural stability to the gel beads. This method can be used with many types of enzymes, such as proteases, carbohydrases, proteases, ligases, isomerases, oxidoreductases, and specialty enzymes. These and other enzymes can be immobilized in the gel beads and utilized in a number of enzymatic processes. Exogenously added ions are not required to maintain the structural stability of these gel beads.

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: An enzymatic method for producing N-formyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester by a condensation reaction between N-formyl-L-aspartic acid and L-phenylalanine methyl ester or D,L-phenylalanine methyl ester, which comprises: supplying an organic phase comprising a water-immiscible solvent containing N-formyl-L-aspartic acid and L- or D,L-phenylalanine methyl ester onto an aqueous phase comprising a thermolysin-like metalloprotease; proceeding the condensation reaction in the aqueous phase to produce N-formyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester; and extracting the N-formyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester thus produced from the aqueous phase to the organic phase.

Abstract: A device for the effective release of cellular moieties, including hormones, wherein a matrix containing a hormone producing cellular moiety is encapsulated with a non-immunogenic polymeric material of poly-para-xylylene or other aromatic based polymer moiety having a membrane portion with a porosity blocking passage therethrough of immunogenic agents and permitting passage therethrough of effective nutrients for said cellular moiety and the hormone produced thereby, an improved matrix for the storage, manufacture, functional testing, and viral infection testing of cellular moieties wherein a collagen based hydrogel is processed to present a liquid phase at host temperature and functions as a substrate for cellular attachment with additives effective for limiting thermal and pressure trauma, and an improved method for the harvesting tissue from organs.

Abstract: Enzymatically cross-linked protein gels and methods for preparing them are disclosed. The methods comprise adding a transglutaminase, such as factor XIII, to a composition of a temperature-sensitive gel-forming protein, such as gelatin or collagen, and incubating the composition and transglutaminase under gel-forming conditions. The resulting gels have superior strength and thermal stability, and can be used within a variety of medical and industrial applications.

Abstract: Water soluble macromers are modified by addition of free radical polymerizable groups, such as those containing a carbon-carbon double or triple bond, which can be polymerized under mild conditions to encapsulate tissues, cells, or biologically active materials. The polymeric materials are particularly useful as tissue adhesives, coatings for tissue lumens including blood vessels, coatings for cells such as islets of Langerhans, coatings, plugs, supports or substrates for contact with biological materials such as the body, and as drug delivery devices for biologically active molecules.