Hedberg Yolanda, Odnevall Wallinder Inger
KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, Stockholm, Sweden.
J Biomed Mater Res B Appl Biomater. 2014 May;102(4):693-9. doi: 10.1002/jbm.b.33048. Epub 2013 Oct 24.
The objective of this study was to investigate the extent of released Co, Cr(III), Cr(VI), and Mo from a biomedical high-carbon CoCrMo alloy exposed in phosphate-buffered saline (PBS), without and with the addition of 10 µM H2 O2 (PBS + H2 O2 ), and 10 g L(-1) bovine serum albumin (PBS + BSA) for time periods up to 28 days. Comparative studies were made on AISI 316L for the longest time period. No Cr(VI) release was observed for any of the alloys in either PBS or PBS + H2 O2 at open-circuit potential (no applied potential). However, at applied potentials (0.7 V vs. Ag/AgCl), Cr was primarily released as Cr(VI). Co was preferentially released from the CoCrMo alloy at no applied potential. As a consequence, Cr was enriched in the utmost surface oxide reducing the extent of metal release over time. This passivation effect was accelerated in PBS + H2 O2 . As previously reported for 316L, BSA may also enhance metal release from CoCrMo. However, this was not possible to verify due to the precipitation of metal-protein complexes with reduced metal concentrations in solution as a consequence. This was particularly important for Co-BSA complexes after sufficient time and resulted in an underestimation of metals in solution.
本研究的目的是调查一种生物医学用高碳钴铬钼合金在磷酸盐缓冲盐水（PBS）中、添加10 μM过氧化氢（PBS + H₂O₂）以及添加10 g L⁻¹牛血清白蛋白（PBS + BSA）的情况下，长达28天内钴、铬（III）、铬（VI）和钼的释放程度。对AISI 316L进行了最长时间的对比研究。在开路电位（无外加电位）下，无论是在PBS还是PBS + H₂O₂中，任何一种合金均未观察到铬（VI）的释放。然而，在施加电位（相对于Ag/AgCl为0.7 V）时，铬主要以铬（VI）的形式释放。在无外加电位时，钴优先从钴铬钼合金中释放。因此，铬在最表面的氧化物中富集，随着时间的推移降低了金属的释放程度。在PBS + H₂O₂中这种钝化作用加速。如先前对316L的报道，牛血清白蛋白也可能增强钴铬钼合金的金属释放。然而，由于金属 - 蛋白质络合物沉淀导致溶液中金属浓度降低，无法对此进行验证。这对于足够时间后的钴 - 牛血清白蛋白络合物尤为重要，并导致溶液中金属的低估。
