title: In vitro studies on silver implanted pure iron by metal vapor vacuum arc technique.
abstract: Pure iron has been verified as a promising biodegradable metal for absorbable cardiovascular stent usage. However, the degradation rate of pure iron is too slow. To accelerate the degradation of the surface of pure iron, silver ions were implanted into pure iron by metal vapor vacuum arc (MEVVA) source at an extracted voltage of 40keV. The implanted influence was up to 2×10(17)ions/cm(2). The composition and depth profiles, corrosion behavior and biocompatibility of Ag ion implanted pure iron were investigated. The implantation depths of Ag was around 60nm. The element Ag existed as Ag2O in the outermost layer, then gradually transited to metal atoms in zero valent state with depth increase. The implantation of Ag ions accelerated the corrosion rate of pure iron matrix, and exhibited much more uniform corrosion behavior. For cytotoxicity assessment, the implantation of Ag ions slightly decreased the viability of all kinds of cell lines used in these tests. The hemolysis rate of Ag ion implanted pure iron was lower than 2%, which was acceptable, whereas the platelet adhesion tests indicated the implantation of Ag ions might increase the risk of thrombosis.
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Huang
authors.affiliation: Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China. Electronic address: yfzheng@pku.edu.cn.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003343:Corrosion; D055664:Electrochemical Techniques; D004912:Erythrocytes / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D007501:Iron / Q000737:chemistry / Q000494:pharmacology*; D008422:Materials Testing; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000187:drug effects; D010973:Platelet Adhesiveness / Q000187:drug effects*; D061251:Primary Cell Culture; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D015607:Stents; D014618:Vacuum; D014835:Volatilization
chemical_list: D001672:Biocompatible Materials; D012834:Silver; D007501:Iron
keywords: Biocompatibility; Corrosion; Pure iron; Silver ion implantation