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.
Claims23
An antioxidant-doped polymeric material containing detectable residual free radicals obtained by the process of irradiating the polymeric material, and then doping it with an antioxidant, thereby forming a gradient of antioxidant in the polymeric material, wherein the an antioxidant-doped polymeric material is non-oxidizing and cross-linked, wherein the antioxidant is vitamin E.
A consolidated and cross-linked UHMWPE that is oxidation and wear resistant obtained by a process comprising the steps of
- (a) providing consolidated and cross-linked UHMWPE that has been irradiated with ionizing radiation;
- (b) doping the consolidated and cross-linked UHMWPE with vitamin E by diffusion, thereby allowing formation of a gradient of vitamin E 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 the uniformity of the vitamin E distribution in the consolidated and cross-linked UHMWPE such that the vitamin E 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.
Dependencies are inferred from the claim text.