Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

Abstract: The present invention relates to a medical prosthesis for use within the body, which is formed of ultra high molecular weight polyethylene having a polymeric structure with less than about 50% crystallinity, less than about 290 Å lamellar thickness and less than about 940 MPa tensile elastic modulus, so as to reduce production of fine particles from the prosthesis during wear of the prosthesis. The present invention also relates to methods of manufacture of such devices and material used therein.

Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

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: 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: A medical prosthesis for use within the body which is formed of ultra high molecular weight polyethylene which has a polymeric structure with less than about 50% crystallinity, less than about 290 .ANG. lamellar thickness and less than about 940 MPa tensile elastic modulus, so as to reduce production of fine particles from the prosthesis during wear of the prosthesis, is described. Methods of manufacture of such devices and material used therein are also provided.

Abstract: Methods for forming implantable composite keratoprostheses are provided. The methods provide keratoprostheses designed to provide a suitable substrate for corneal epithelial cell growth while maintaining the desirable characteristics of hydrogels, i.e., clarity, flexibility and the ability to allow diffusive flow of nutrients. In a preferred embodiment the method includes placing corneal tissue in a mold having a corneal implant shape and crosslinking a polymeric solution to chemically bond a biocompatible hydrogel having a thickness between approximately 50 and 100 microns to the corneal tissue to form the keratoprosthesis. Upon implantation, the corneal tissue abuts epithelial cells surrounding the keratoprosthesis. In another preferred embodiment, a polymer solution is placed between the corneal tissue and a pre-formed hydrogel and then polymerized so that the polymer solution couples to both the hydrogel and the corneal tissue.

Abstract: Methods are provided for the synthesis of poly(ethylene oxide) ("PEO") star macromolecules including functionalizable groups. In one embodiment, a core molecule including a plurality of dendritic branches or having a comb structure, and including a plurality of accessible reactive groups is reacted with functionalizable poly(ethylene oxide) ("PEO") molecules. The functionalizable poly(ethylene oxide) molecules include a reactive group capable of reacting with the reactive group on the core molecule, and a functionalizable group capable of being chemically modified, which optionally is protected. In the reaction, the PEO molecules are covalently attached to the core molecule, to form a PEO star macromolecule with terminal functionalizable groups. Preferably, the functionalizable PEO is a heterofunctional linear PEO which includes the reactive group at one terminus and the functionalizable group at the other terminus.

Abstract: A thermoplastic biodegradable material is prepared from a continuous hydrophobic polysaccharide phase and a discontinuous phase of dispersed unmodified polysaccharide or bicontinuous phases of both. The material is easily processed into a wide variety of articles of manufacture that have sufficient physical properties for the intended use, yet degrades into nontoxic components in a reasonable timeframe in landfills or elsewhere in the environment.

Abstract: A method for immobilizing polyethylene oxide (PEO) star molecules in the form of hydrogel layers and a product thereof are disclosed. The PEO star molecules are biocompatible and demonstrate non-thrombogenic properties. As such, the PEO star molecule layers have numerous biomedical applications, such as on contact lenses. The hydrogel layers contain a high percentage of terminal hydroxyl groups for attachment of affinity ligands and can be used for separating and purifying therapeutic proteins.

Abstract: This invention pertains to a method for immobilizing polyethylene oxide (PEO) star molecules in the form of hydrogels. the PEO star molecules are biocompatible and demonstrate non-thrombogenic properties. As such, the PEO star molecules have numerous uses for biomedical applications. The hydrogels contain a high percentage of terminal hydroxyl groups for attachment of affinity ligands and can be used for separating and purifying therapeutic proteins.

Abstract: A crosslinked polymer network comprising the reaction product of a polyethylene oxide and a polyglycidoxypropylsiloxane is described. These materials form hydrogel networks having very high partition coefficients for selected pharmaceuticals and are suitable for controlled drug release and water purification.

Abstract: A crosslinked polymer network comprising the reaction product of a polyethylene oxide and a polyglycidoxypropylsiloxane is described. These materials demonstrate low in vivo platelet retention as well as a low thrombogenicity. As such, they can provide antithrombogenic properties to blood contacting devices such as catheters, artificial hearts, ventricular grafts and cardiovascular suture.

Abstract: Apparatus for rapidly measuring blood viscosity including a hollow column of narrow bore in fluid communication with a chamber containing a porous bed and means for measuring blood flow rate within the column. The specific permeability of the bed and the pressure gradient are selected so that in combination they result in an equivalent average wall shear stress of about 1 dyn/cm.sup.2 or less.

Abstract: A contact lens comprising a silicone polymer or copolymer core and a hydrophilic polymer surface grafted to the core is formed by contacting a silicone with a free radical polymerizable precursor to the polymer in a liquid state and subjecting the precursor and silicone to a high dose of ionizing radiation for a short period. The radiation dose, time of radiation and temperature are controlled to produce an optically clear contact lens by forming a smooth surface of the polymer grafted to the silicone, preventing substantial migration of the precursor into the silicone and preventing localized high concentration of hydrophilic polymer on the silicone surface.