电化学抛光对NiTi支架生物相容性的影响

Effect of Electrochemical Polishing on Biocompatibility of NiTi Stents

针对目前NiTi支架电化学抛光表面形貌不理想的情况,提出了一种改进的电化学抛光方法(冰醋酸-高氯酸-A-B),并采用此抛光工艺对NiTi支架(Ti-50.8at.%Ni)进行了电化学抛光。采用扫描电子显微镜(SEM)表征了抛光工艺对NiTi支架表面形貌的影响,并利用电化学方法研究了不同表面处理(电化学抛光、机械抛光、酸洗)对同种成分的NiTi试片在Hanks′溶液中腐蚀性能的影响。研究结果表明,此工艺下的电化学抛光有效降低了NiTi支架的表面粗糙度,改善了表面质量;电化学抛光的NiTi试片在Hanks′溶液中耐蚀性的提高也为电化学抛光NiTi支架的应用提供了实验依据。

It has been known that the surface quality of artery stents has a significant influence on the biocompatibility. In particular, a smooth surface is required. In this paper a modified electrolyte （HClO4-CH3COOH-A-B） for NiTi stents was presented, and this electrolyte was used in electrochemically polishing the NiTi stents （Ti-50.8at.%Ni）. Morphologies of the polished NiTi sheet material and stents were characterized by SEM and the test of potentiodynamic polarization was carried out in Hanks＇ solution to verify the corrosion resistance of the stents through different surface treatment （electrochemical polishing, mechanical polishing and chemical etching）. The results revealed that the electrochemical polishing using this electrolyte could reduce the surface roughness of the stents significantly and the improved corrosion resistance of the polished NiTi sheet material in Hanks＇ solution could provide the basis for application of the electrochemically polished NiTi stents.