title: In vitro degradation and biocompatibility of Fe-Pd and Fe-Pt composites fabricated by spark plasma sintering.
abstract: In order to obtain biodegradable Fe-based materials with similar mechanical properties as 316L stainless steel and faster degradation rate than pure iron, Fe-5 wt.%Pd and Fe-5 wt.%Pt composites were prepared by spark plasma sintering with powders of pure Fe and Pd/Pt, respectively. The grain size of Fe-5 wt.%Pd and Fe-5 wt.%Pt composites was much smaller than that of as-cast pure iron. The metallic elements Pd and Pt were uniformly distributed in the matrix and the mechanical properties of these materials were improved. Uniform corrosion of Fe-Pd and Fe-Pt composites was observed in both electrochemical tests and immersion tests, and the degradation rates of Fe-Pd and Fe-Pt composites were much faster than that of pure iron. It was found that viabilities of mouse fibroblast L-929 cells and human umbilical vein endothelial cells (ECV304) cultured in extraction mediums of Fe-Pd and Fe-Pt composites were close to that of pure iron. After 4 days' culture, the viabilities of L-929 and ECV304 cells in extraction medium of experimental materials were about 80%. The result of direct contact cytotoxicity also indicated that experimental materials exhibited no inhibition on vascular endothelial process. Meanwhile, iron ions released from experimental materials could inhibit proliferation of vascular smooth muscle cells (VSMC), which may be beneficial for hindering vascular restenosis. Furthermore, compared with that of as-cast pure iron, the hemolysis rates of Fe-Pd and Fe-Pt composites were slightly higher, but still within the range of 5%, which is the criteria for good blood compatibility. The numbers of platelet adhered on the surface of Fe-Pd and Fe-Pt composites were lower than that of pure iron, and the morphology of platelets kept spherical. To sum up, the Fe-5 wt.%Pd and Fe-5 wt.%Pt composites exhibited good mechanical properties and degradation behavior, closely approaching the requirements for biodegradable metallic stents.
authors.affiliation: State Key Laboratory for Turbulence and Complex System, College of Engineering, Peking University, Beijing 100871, China; Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.
authors.forename: T
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: J
authors.initials: J
authors.lastname: Cheng
authors.affiliation: State Key Laboratory for Turbulence and Complex System, College of Engineering, Peking University, Beijing 100871, China; Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China; Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China. Electronic address: yfzheng@pku.edu.cn.
authors.forename: Y F
authors.initials: YF
authors.lastname: Zheng
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000138:chemical synthesis; D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000633:toxicity; D001826:Body Fluids / Q000737:chemistry; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D019245:Compressive Strength; D003343:Corrosion; D055119:Elastic Modulus; D004563:Electrochemistry / Q000379:methods; D006244:Hardness; D007501:Iron / Q000737:chemistry* / Q000633:toxicity*; D008422:Materials Testing; D051379:Mice; D010165:Palladium / Q000737:chemistry* / Q000633:toxicity*; D058626:Plasma Gases / Q000737:chemistry; D010984:Platinum / Q000737:chemistry* / Q000633:toxicity*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D058626:Plasma Gases; D010984:Platinum; D010165:Palladium; D007501:Iron
keywords: Biocompatibility; Biodegradable metal; Corrosion; Fe–Pd composite; Fe–Pt composite