title: Biocompatibility of ultra-high molecular weight polyethylene (UHMW-PE) stabilized with alpha-tocopherol used for joint endoprostheses assessed in vitro.
abstract: Adding the natural antioxidant alpha-tocopherol to ultra-high molecular weight polyethylene (UHMW-PE) can remarkably delay the oxidation of hip cups made thereof. However, alpha-tocopherol is likely to undergo different chemical transformations during manufacturing and sterilization of hip cups than in human metabolism. Therefore, the biocompatibility of the putative transformation products has to be investigated. In-vitro tests with L929 mice fibroblast-cells gave no evidence for cytotoxicity. To further ensure the biocompatibility, in-vitro tests with human cells were carried out in this study. Two different human cell lines, one adherent cell line, HF-SAR, and one suspension culture, GSJO, were tested on UHMW-PE-tablets (diameter: 15 mm; thickness: 2 mm; processed according to standard procedures for artificial hip-cups) with and without alpha-tocopherol with respect to cell viability, proliferation and morphology by means of cell counting, WSt-1 proliferation assay and scanning electron microscopy. Similar proliferation rates were found with both polyethylene samples. Further, we found intact morphology in light and electron microscopy on each substrate. The morphologic characteristics of skin fibroblasts were not changed by any material. Normal adherence and spreading of the fibroblasts was found on controls of glass, as well as on polystyrene and on stabilized and unstabilized polyethylene. The characteristic behaviour as suspension of the GSJO cells remained unchanged. The mitochondrial activity, as studied by WST-1 cell proliferation reagent, was identical on each substrate during the whole observation period of 7 days.
authors.affiliation: Department of Chemistry of Polymeric Materials, University of Leoben, 8700 Leoben, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Wolf
authors.forename: Klaus
authors.initials: K
authors.lastname: Lederer
authors.forename: Roswitha
authors.initials: R
authors.lastname: Pfragner
authors.forename: Konrad
authors.initials: K
authors.lastname: Schauenstein
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ingolic
authors.forename: Veronika
authors.initials: V
authors.lastname: Siegl
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002460:Cell Line; D049109:Cell Proliferation; D048429:Cell Size; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007595:Joint Prosthesis; D020959:Polyethylene / Q000737:chemistry*; D024502:alpha-Tocopherol / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D020959:Polyethylene; D024502:alpha-Tocopherol