The aim of this work was to compare the microstructures of two high noble experimental Au-Pt alloys with similar composition with their corrosion and biocompatibility in vitro. We showed that Au-Pt II alloy, composed of 87.3 wt.% Au, 9.9 wt.% Pt, 1.7 wt.% Zn and 0.5 wt.% Ir + Rh + In, although possessing better mechanical properties than the Au-Pt I alloy (86.9 wt.% Au, 10.4 wt.% Pt, 1.5 wt.% Zn and 0.5 wt.% Ir + Rh + In), exerted higher adverse effects on the viability of L929 cells and the suppression of rat thymocyte functions, such as proliferation activity, the production of Interleukin-2 (IL-2), expression of IL-2 receptor and activation — induced apoptosis after stimulation of the cells with Concanavalin-A. These results correlated with the higher release of Zn ions in the culture medium. As Zn2+, at the concentrations which were detected in the alloy’s culture media, showed a lesser cytotoxic effect than the Au-Pt conditioning media, we concluded that Zn is probably not the only element responsible for alloy cytotoxicity. Microstructural characterization of the alloys, performed by means of scanning electron microscopy in addition to energy dispersive X-ray and X-ray diffraction analyses, showed that Au-Pt I is a two-phase alloy containing a dominant Au-rich α1 phase and a minor Pt-rich α2 phase. On the other hand, the Au-Pt II alloy additionally contained three minor phases: AuZn3, Pt3Zn and Au1.4Zn0.52. The highest content of Zn was identified in the Pt3Zn phase. After conditioning, the Pt3Zn and AuZn3 phases disappeared, suggesting that they are predominantly responsible for Zn loss, lower corrosion stability and subsequent lower biocompatibility of the Au-Pt II alloy.

中文翻译：

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高贵金铂牙科合金微观结构对其体外腐蚀和生物相容性的影响

这项工作的目的是比较两种具有相似成分的高贵实验 Au-Pt 合金的微观结构及其体外腐蚀和生物相容性。我们展示了 Au-Pt II 合金，由 87​​.3 wt.% Au、9.9 wt.% Pt、1.7 wt.% Zn 和 0.5 wt.% Ir + Rh + In 组成，尽管具有比 Au-Pt I 更好的机械性能合金（86.9 wt.% Au、10.4 wt.% Pt、1.5 wt.% Zn 和 0.5 wt.% Ir + Rh + In）对 L929 细胞的活力和大鼠胸腺细胞功能的抑制产生更高的不利影响，例如作为增殖活性，白细胞介素 2 (IL-2) 的产生、IL-2 受体的表达和激活 - 在用刀豆蛋白 A 刺激细胞后诱导细胞凋亡。这些结果与培养基中锌离子的更高释放相关。作为 Zn2+，在合金培养基中检测到的浓度下，显示出比 Au-Pt 调节培养基更小的细胞毒性作用，我们得出结论，Zn 可能不是造成合金细胞毒性的唯一元素。除了能量色散 X 射线和 X 射线衍射分析外，还通过扫描电子显微镜进行的合金显微组织表征表明，Au-Pt I 是一种两相合金，含有主要的富 Au α1 相和次要富铂 α2 相。另一方面，Au-Pt II 合金还包含三个次要相：AuZn3、Pt3Zn 和 Au1.4Zn0.52。在 Pt3Zn 相中鉴定出最高含量的 Zn。调节后，Pt3Zn 和 AuZn3 相消失，表明它们主要是造成 Zn 损失的原因，