Methods for making oxidation resistant polymeric material
AssigneesThe General Hospital Corporation, Cambridge Polymer Group, Inc.
InventorsOrhun K. Muratoglu, Stephen H. Spiegelberg
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Abstract
The present invention relates to methods for making oxidation resistant medical devices that comprise polymeric materials, for example, ultra-high molecular weight polyethylene (UHMWPE). The invention also provides methods of making antioxidant-doped medical implants, for example, doping of medical devices containing cross-linked UHMWPE with vitamin E by diffusion and materials used therein.
Claims25
A method of making an oxidation and wear resistant ultrahigh molecular weight polyethylene (UHMWPE) for use in a medical implant, wherein the method comprises:
- (a) providing consolidated and cross-linked UHMWPE that has been irradiated with ionizing radiation;
- (b) doping the consolidated and cross-linked UHMWPE with an antioxidant by diffusion, thereby allowing formation of a gradient of an antioxidant in the consolidated and cross-linked UHMWPE;
- and
- (c) annealing the consolidated and cross-linked UHMWPE at a temperature below its melting point to increase uniformity of antioxidant distribution in the consolidated and cross-linked UHMWPE such that the antioxidant can react with free radicals throughout the consolidated and cross-linked UHMWPE,
- wherein the method provides a consolidated and cross-linked UHMWPE that is oxidation and wear resistant and can be used in a medical implant.
A method of making a medical implant comprising oxidation and wear resistant ultrahigh molecular weight polyethylene (UHMWPE), wherein the method comprises:
- (a) providing consolidated and cross-linked UHMWPE that has been irradiated with ionizing radiation;
- (b) doping the consolidated and cross-linked UHMWPE with an antioxidant by diffusion, thereby allowing formation of a gradient of an antioxidant in the consolidated and cross-linked UHMWPE;
- (c) annealing the consolidated and cross-linked UHMWPE at a temperature below its melting point to increase uniformity of antioxidant distribution in the consolidated and cross-linked UHMWPE such that the antioxidant can react with free radicals throughout the consolidated and cross-linked UHMWPE, and
- (d) machining the consolidated and cross-linked UHMWPE, thereby forming the medical implant comprising oxidation and wear resistant UHMWPE.
A method of making an interlocked hybrid medical device comprising oxidation and wear resistant ultrahigh molecular weight polyethylene (UHMWPE), wherein the method comprises:
- (a) providing consolidated and cross-linked UHMWPE that has been irradiated with ionizing radiation;
- (b) doping the consolidated and cross-linked UHMWPE with an antioxidant by diffusion, thereby allowing formation of a gradient of an antioxidant in the consolidated and cross-linked UHMWPE;
- (c) annealing the consolidated and cross-linked UHMWPE at a temperature below its melting point to increase uniformity of antioxidant distribution in the consolidated and cross-linked UHMWPE such that the antioxidant can react with free radicals throughout the consolidated and cross-linked UHMWPE;
- d) compression molding the antioxidant-doped UHMWPE to the counter face of a metallic material, thereby forming an interlocked hybrid material having an interface between the antioxidant-doped UHMWPE and the metallic material;
- and
- e) machining the interlocked hybrid material to form the interlocked hybrid medical device having the oxidation and wear resistant UHMWPE.
Dependencies are inferred from the claim text.