Diffusion of vitamin E in ultra-high molecular weight polyethylene

Biomaterials. 2007 Dec;28(35):5225-37. doi: 10.1016/j.biomaterials.2007.08.025. Epub 2007 Sep 19.

Abstract

Vitamin E-doped, radiation crosslinked ultra-high molecular weight polyethylene (UHMWPE) is developed as an alternate oxidation and wear resistant bearing surface in joint arthroplasty. We analyzed the diffusion behavior of vitamin E through UHMWPE and predicted penetration depth following doping with vitamin E and subsequent homogenization in inert gas used to penetrate implant components with vitamin E. Crosslinked UHMWPE (65- and 100-kGy irradiation) had higher activation energy and lower diffusion coefficients than uncrosslinked UHMWPE, but there were only slight differences in vitamin E profiles and penetration depth between the two doses. By using homogenization in inert gas below the melting point of the polymer following doping in pure vitamin E, the surface concentration of vitamin E was decreased and vitamin E stabilization was achieved throughout a desired thickness. We developed an analytical model based on Fickian theory that closely predicted vitamin E concentration as a function of depth following doping and homogenization.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Biocompatible Materials / radiation effects
  • Cross-Linking Reagents
  • Diffusion
  • Dose-Response Relationship, Radiation
  • Gamma Rays
  • Polyethylenes*
  • Temperature
  • Time Factors
  • Vitamin E / metabolism*
  • Vitamin E / radiation effects

Substances

  • Biocompatible Materials
  • Cross-Linking Reagents
  • Polyethylenes
  • ultra-high molecular weight polyethylene
  • Vitamin E