Surface crosslinked ultrahigh molecular weight polyethylene with vitamin-E and D-sorbitol as synergistic antioxidants for use in total joint replacements
摘要
Wear and oxidation resistance are among the primary requirements for successful and sustainable total joint replacements (TJRs). Both of these factors are major causes of TJRs failure. To address these issues and enhance the service life of TJRs, the effects of vitamin E (VE) and vitamin E-D-sorbitol (VE-DS), which are antioxidants (AOs), on stabilizing ultrahigh-molecular-weight polyethylene (UHMWPE) are presented. These antioxidants were blended with control-UHMWPE at a concentration of 0.3 % by weight and consolidated by compression molding. Wear occurs on the surface, and restricting the crosslinking to a layer on the surface is desirable, as bulk crosslinking reduces the toughness and fatigue strength of the implant. In this study, surface chemical crosslinking of control-UHMWPE, VE-UHMWPE and VE-DS-UHMWPE with dicumyl peroxide (DCP) is presented. The crosslinked density, crystallinity, wear volume, mechanical performance, biocompatibility and oxidation stability assessed by oxidation induction time (OIT) of the UHMWPE blends were characterized through different techniques. The control-UHMWPE blend showed the highest wear resistance but the lowest OIT, while the VE-DS-UHMWPE blend displayed highest crystallinity, best mechanical performance and the highest OIT, exhibiting the synergistic effect of vitamin E and D-sorbitol on the oxidation resistance of UHMWPE.