title: In-vitro evaluation of the cytocompatibility of wear particles generated by UHMWPE/zirconia friction.
abstract: Cytotoxicity of wear products generated by UHMWPE/yttria partially stabilized zirconia (YPSZ) friction and UHMWPE/surface-nitrided Ti-6Al-4V friction in pseudo-extracellular fluid (PECF) at 37 degrees C was evaluated.  Though the amount of abraded UHMWPE against YPSZ was almost the same as that against nitrided Ti-6Al-4V, the wear products generated by UHMWPE/YPZ friction significantly inhibited cell growth while those by UHMWPE/nitrided Ti-6Al-4V friction showed no growth inhibition. Dissolved Zr and Y ions were at least 70 times less than the amount causing growth inhibition.  The cytotoxicity was caused mainly by the particles less than 0.22 mum in size.  Amorphous zirconium-containing particles (5-20 nm) found in the PECF, formed presumably by stress corrosion, would be a responsible factor for the cytotoxicity.
authors.affiliation: Mechanical Engineering Laboratory, AIST, Ministry of International Trade and Industry, Ibaraki, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Tateishi
authors.forename: S
authors.initials: S
authors.lastname: Niwa
authors.forename: S
authors.initials: S
authors.lastname: Tange
mesh_terms: D001672:Biocompatible Materials; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects; D017276:Friction; D006801:Humans; D008422:Materials Testing; D010316:Particle Size; D011095:Polyethylenes / Q000633:toxicity*; D019736:Prostheses and Implants; D015019:Yttrium / Q000633:toxicity*; D015040:Zirconium / Q000633:toxicity*