Stepan L L, Levi D S, Gans E, Mohanchandra K P, Ujihara M, Carman G P
Biomedical Engineering IDP, UCLA, Los Angeles, California 90095, USA.
J Biomed Mater Res A. 2007 Sep 1;82(3):768-76. doi: 10.1002/jbm.a.31192.
Thin film nitinol and single crystal Ni-Mn-Ga represent two new shape memory materials with potential to be used as percutaneously placed implant devices. However, the biocompatibility of these materials has not been adequately assessed. Immersion tests were conducted on both thin film nitinol and single crystal Ni-Mn-Ga in Hank's balanced salt solution at 37 degrees C and pH 7.4. After 12 h, large pits were found on the Ni-Mn-Ga samples while thin film nitinol displayed no signs of corrosion. Further electrochemical tests on thin film nitinol samples revealed breakdown potentials superior to a mechanically polished nitinol disc. These results suggest that passivation or electropolishing of thin film nitinol maybe unnecessary to promote corrosion resistance.
薄膜镍钛诺和单晶镍锰镓是两种新型形状记忆材料，有潜力用作经皮植入装置。然而，这些材料的生物相容性尚未得到充分评估。在37摄氏度和pH值为7.4的汉克斯平衡盐溶液中对薄膜镍钛诺和单晶镍锰镓进行了浸泡试验。12小时后，在镍锰镓样品上发现了大坑，而薄膜镍钛诺没有腐蚀迹象。对薄膜镍钛诺样品的进一步电化学测试表明，其击穿电位优于机械抛光的镍钛诺圆盘。这些结果表明，薄膜镍钛诺的钝化或电解抛光对于提高耐腐蚀性可能没有必要。
