Comparing the Biocompatibility of Electropolished and Magnetoelectropolished Nitinol

摘要

In the quest to develop the next generation of implant materials that are more biocompatible, chromium has been introduced as a ternary element into Nitinol to impart improved corrosion resistance, since both titanium and chromium are highly passivating ele-ments. However, all implant devices must be surface finished prior to application. Electropolishing (EP) is a standard surface treatment process employed as a final finish in the manufacture of Nitinol devices. Recently, the beneficial effects of magnetoelectropol-ishing (MEP) have been recognized. This investigation focuses on the effect of EP and MEP on the corrosion resistance and cytotoxicity of NiTi and NiTiCr. The concentration of dissolved metal ions in solution after cyclic polarization tests were measured by ICPMS. HUVEC cells were exposed to various proportions of the resulting electrolyte and fresh PBS, and cell proliferation and viability were assessed by SRB assays. The morphology and depth profile of the EP and MEP alloys were analyzed using SEM and XPS analyses respectively.