Vitamin E Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin E, including details on benefits, dosage, supplements, antioxidants.

Migration stability of alpha-tocopherol in irradiated UHMWPE.

Oral E, Wannomae KK, Rowell SL, Muratoglu OK

Orthopaedic Biomechanics and Biomaterials Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital, 55 Fruit Street, GRJ 1206, Boston, MA 02114, USA.

The oxidation resistance of irradiated ultra-high molecular weight polyethylene (UHMWPE) components used in total joint arthroplasty can be improved by adding alpha-tocopherol (vitamin E) through diffusion. To ensure long-term oxidative stability, a minimum alpha-tocopherol concentration needs to be maintained throughout these components. Migration of alpha-tocopherol out of the components is one mechanism that could compromise long-term oxidative stability. We hypothesized that alpha-tocopherol could elute out during standard implant fabrication steps such as cleaning as well as during in vivo use. We doped 85 kGy irradiated UHMWPE with alpha-tocopherol at 120 degrees C and homogenized at 120 degrees C. We determined the extent of elution of alpha-tocopherol or its effect on oxidative stability following cleaning in isopropyl alcohol (IPA) and following 5 million cycles (MC) of simulated normal gait in bovine serum. There was no significant elution of alpha-tocopherol in repeated and prolonged cleaning in IPA as measured by average surface and bulk alpha-tocopherol concentrations. There was no change in the oxidative stability following 5 MC of hip simulator testing, indicating minimal elution during simulated normal gait.

Published 26 December 2005 in Biomaterials, 27(11): 2434-9.
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