Effect of vanadium released from micro-arc oxidized porous Ti6Al4V on biocompatibility in orthopedic applications.

MAO-treated porous Ti6Al4V holds enormous potential for use in orthopedic implants due to their excellent biocompatibility and favourable mechanical strength. However, the effects on the V ion accumulation and release following the MAO-treated Ti6Al4V remain undetermined. The aim of the present study was to assess the effects of Vanadium on biocompatibility. In this study, the surface features and chemical compositions were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). The ion release of Ti, Al and V was quantitatively measured by inductively-coupled plasma mass spectroscopy (ICP-MS) after immersion in Hanks' solution. To probe the mechanism of V release, the corrosion resistance of porous Ti6Al4V before and after the MAO process was evaluated by electrochemical tests. Thereafter, the effects on the biocompatibility were tested in vitro by cell culture assays and then in vivo by subcutaneous embedment. Finally, the bone tissue response and in vivo release profile of V ions were characterized by intra-osseous implantation. Therefore, this study suggests that the effect of V released from MAO-treated porous Ti6Al4V on biocompatibility and application safety is small and preventable.