Syrett B C, Davis E E
J Biomed Mater Res. 1979 Jul;13(4):543-56. doi: 10.1002/jbm.820130403.
A high-strength, high-ductility, austenitic stainless steel has been evaluated for use in surgical implants by performing in vivo tests in rats, rabbits, dogs, and rhesus monkeys. This stainless steel, a TRIP (Transformation Induced Plasticity) steel containing about 4% Mo, was compared with two alloys in current clinical use: Type 316L stainless steel and cast Vitallium. Compared with the other two alloys, cast Vitallium generally had higher resistance to corrosion and superior biocompatibility in all animals. The tests in rats and dogs indicated that the corrosion resistances of the TRIP steel and the Type 316L stainless steel were similar and that the tissue reactions caused by these alloys were also similar. However, in rhesus monkeys, the TRIP steel was shown to be susceptible to stress-corrosion cracking and much more susceptible to crevice corrosion than Type 316L stainless steel. Limited tests in rabbits supported the observation that the TRIP steel is susceptible to stress-corrosion cracking. These inconsistencies in the in vivo tests underline the need for a reevaluation of the popular test techniques and of the animals commonly chosen for assessing the suitability of candidate implant materials. The "worst case" results from the rhesus monkey tests were entirely consistent with previous results obtained from in vitro studies. However, further work must be performed before the behavior of metals in humans, rhesus monkeys, or any other animal, can be predicted with confidence from an in vitro test program.
一种高强度、高延展性的奥氏体不锈钢已通过在大鼠、兔子、狗和恒河猴身上进行体内试验来评估其在外科植入物中的应用。这种不锈钢是一种含约4%钼的相变诱发塑性（TRIP）钢，与目前临床使用的两种合金进行了比较：316L型不锈钢和铸造钴铬钼合金。与其他两种合金相比，铸造钴铬钼合金在所有动物中通常具有更高的耐腐蚀性和更好的生物相容性。在大鼠和狗身上进行的试验表明，TRIP钢和316L型不锈钢的耐腐蚀性相似，并且这些合金引起的组织反应也相似。然而，在恒河猴身上，TRIP钢被证明易受应力腐蚀开裂影响，并且比316L型不锈钢更容易受到缝隙腐蚀。在兔子身上进行的有限试验支持了TRIP钢易受应力腐蚀开裂影响的观察结果。体内试验中的这些不一致情况突出表明，需要重新评估常用的测试技术以及通常用于评估候选植入材料适用性的动物。恒河猴试验的“最坏情况”结果与先前体外研究获得的结果完全一致。然而，在能够根据体外试验程序可靠地预测金属在人类、恒河猴或任何其他动物中的行为之前，还必须进行进一步的研究。
