医用可降解Mg-3Zn-0.5Sr合金耐蚀性及细胞毒性

采用仿生法在Mg-3Zn-0.5Sr合金表面制备涂层，通过SEM，EDS和XRD分析表征涂层形貌和结构;采用电化学实验和浸泡腐蚀实验来研究涂层对合金降解速率的影响;采用生物毒性实验验证有无涂层Mg-3Zn-0.5Sr合金的毒性等级.实验结果表明:在Mg-3Zn-0.5Sr合金表面可以沉积致密的羟基磷灰石(HA)涂层，厚度约为30~40μm，HA涂层可以有效地降低Mg合金的降解速率;在体积分数为25%的有无涂层合金浸提液中培养细胞4d，细胞相对增值率均超过100%，有无涂层合金的细胞毒性均为0级.

Corrosion Resistance and Cytotoxicity of Medical Degradable Mg-3Zn-0.5Sr Alloy

The hydroxyapatite (HA) coating was prepared on the surface of Mg-3Zn-0.5Sr alloy by bionic method. The morphology and structure of the coating were characterized by SEM， EDS and XRD. Electrochemical and immersion corrosion experiments were carried out to study the degradation of the alloy and cytotoxicity experiments were also subjected to the HA-coated and uncoated Mg alloy samples. The results show that a dense HA layer with the thickness of 30~40μm can be deposited on the surface of the Mg-3Zn-0.5Sr alloy， which can effectively reduce the degradation rate of this alloy. Relative viability of cells is more than 100% and all samples have cytotoxicity scores of 0， after the cells are cultured in the extracts with the volume fraction of 25% for 4 days.