Abstract: The present invention relates to a block copolymer containing 1-50 first polymer segments and 1-50 second polymer segments. Each first polymer segment has an average mole fraction of monomers possessing a branch point of 0.0001 to 1, whereas each second polymer segment has an average mole fraction of monomers possessing a branch point of 0 to 0.5. The average molecular weights range from 5-2,000 kDa for the first polymer segments, which constitute 5-95% by weight of the block copolymer. The average molecular weights also range from 5-2,000 kDa for the second polymer segments, which constitute 5-95% by weight of the block copolymer. The ratio of the average mole fraction of monomers possessing a branch point of the second polymer segments to that of the first polymer segments is 0 to 0.5. An example of such a copolymer has ethylene oxide or ethylene oxide/propylene oxide as the first polymer segment and polysulfone as the second polymer segment. This block copolymer can further be blended with a bulk polymer.

Abstract: The invention features an empty device for receiving a bioactive agent. The device includes a biocompatible and semi-permeable membrane that defines an enclosed space; the membrane also has at least one end that defines an opening for introducing the bioactive agent into the enclosed space. The device is configured to be placed in an animal.In one embodiment of the invention, the membrane has an inner surface and an outer surface, where the inner surface defines the inner surface, and includes a biocompatible adhesive in the general region of the opening to allow sealing of the opening after the introduction of the bioactive agent into the enclosed space.Another embodiment of the invention includes a biocompatible frame mounted in supporting relationship to the membrane and defining an opening for introducing the bioactive agent into the enclosed space. The frame has greater porosity than the membrane.

Abstract: The invention is based in part on the observation that significant portions of porcine livers appear to remain intact after perfusion by standard methods, suggesting that the perfusion procedures employed do not result in complete enzymatic digestion. Recovery of cells is therefore substantially lower than would be possible if the organs were thoroughly digested. It is found that increased perfusion flow rate, occlusion of at least one major blood vessel leading out of the organ, increased enzymatic digestion time, and vigorous tissue dissociation techniques can be combined to afford a uniquely high yield of viable cells.

Abstract: The invention features a method of processing cryopreserved cells by thawing and equilibrating the cells at warm temperatures (e.g., between 30.degree. C. and 43.degree. C). Either the cell suspension in the cryoprotective medium is thawed to a temperature between 35.degree. C. and 43.degree. C. or the cryoprotective medium is equilibrated with a culture medium at a temperature between 35.degree. C. and 43.degree. C., or both steps are carried out at the warm temperatures. By thawing and equilibrating the cryopreserved cells at warm temperatures, the viability, (especially after 3 hours of culture), and metabolic activity (i.e., diazepam metabolism) of the cells can be improved over traditional cold cell processing (i.e., at temperatures of between 2.degree. C. and 8.degree. C.).

Abstract: The invention features a method of processing cells in a closed system that results in a suspension of cells in a transfer vessel containing a target number of cells. The number of cells in the closed vessel is determined from the cell concentration (i.e., the number of viable cells/mL) in the closed vessel and the total volume of the suspension in the closed vessel. The volume of the suspension in the closed vessel can be determined from the weight of the suspension and its density. In particular, the cells are preserved in a protective medium and are recovered substantially free of the protective medium in a closed vessel containing the known number of cells in a suspension.

Abstract: A method for preparation of biodegradable polymeric drug delivery devices using relatively low temperatures and non-aqueous solutions which is particularly useful with polyanhydrides, thermolabile drugs, and in forming multi-layered devices.In a first embodiment, the polymer is dissolved in a volatile organic solvent, the drug is dispersed or dissolved in the polymer solution, the mixture is suspended in an organic oil, and the organic solvent is extracted into the oil, creating microspheres. The preferred polymers are polyanhydrides since they are biodegradable and have been proven to be useful in vivo.In a second embodiment, the polymer is dissolved in organic solvent with or without the drug, and the mixture is suspended in glycerol. The suspension is frozen and the organic solvent slowly evaporated.

Abstract: A method and apparatus for reducing the levels of low density lipoproteins (LDL) in blood is disclosed. The LDL is contacted with an enzyme which modifies it in a manner such that the LDL is rapidly removed endogenously by the patients' own metabolic processes. The enzyme may be introduced into the patient by injection, transdermal transport, nasal insufflation and ingestion. Additionally, the enzyme may be contained in a reactor for both in vivo and extracorporeal use.

Abstract: Levels of bilirubin in mammalian serum are controlled by administering to the mammalian intestinal tract a substance (a "bilirubin deactivator") that converts unconjugated bilirubin into nontoxic, physiologically compatible products, thereby reducing reabsorption of unconjugated bilirubin in enterohepatic circulation. Useful bilirubin deactivators include those which specifically adsorb the bilirubin and are excreted, and "bilirubin conversion enzymes", i.e., enzymes that operate on the unconjugated bilirubin substrate to yield products that are physiologically compatible in that they are not reabsorbed, or, if reabsorbed, they are nontoxic in the blood stream.

Abstract: A therapeutically effective amount of soluble phospholipase A.sub.2 is administered into a subject for lowering the low density lipoproteins ("LDL") in the blood. Phospholipase A.sub.2 modifies the plasma LDL by hydrolyzing the phospholipids present in LDL. As a result, the modified LDL is rapidly removed from the bloodstream by the catabolic processes.