Miao Hongwei, Zhang Dandan, Chen Chenxin, Zhang Lei, Pei Jia, Su Yun, Huang Hua, Wang Zhongchang, Kang Bin, Ding Wenjiang, Zeng Hui, Yuan Guangyin
National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, School of Materials Science and Engineering, Shanghai 200240, China.
International Iberian Nanotechnology Laboratory, Braga 4715-330, Portugal.
ACS Biomater Sci Eng. 2019 Mar 11;5(3):1623-1634. doi: 10.1021/acsbiomaterials.8b01563. Epub 2019 Feb 5.
Various kinds of biodegradable Mg alloys have been developed in recent years due to their appropriate mechanical properties, biodegradation, and good biocompatibility. In this study, Mg-2.0Zn-Gd alloys ( = 0.5, 1.0, 1.5, and 2.0 wt %) were prepared. Hot extrusion was applied in order to refine the microstructure and improve the degradation resistance. The microstructure, mechanical properties, and in vitro degradation behavior of Mg-2.0Zn-Gd alloys were investigated first. The as-extruded Mg-2.0Zn-1.0Gd alloy exhibits excellent mechanical properties (UTS 338 MPa, YS 284 MPa, elongation 24%) and low in vitro degradation rate (0.24 mm/year) with uniform degradation morphology, and then, this alloy was selected for further assessments. The cytotoxicity of as-extruded Mg-2.0Zn-1.0Gd alloy to MC3T3-E1 cell is found to be grade 0-1, indicating good biocompatibility. The in vivo experiment shows that the in vivo degradation rate of this alloy is about 0.31 mm/y after 30 days implantation in cranial defect of Sprague-Dawley rats. All of these indicate a promising prospect of Mg-2.0Zn-1.0Gd alloy as biodegradable applications, especially as orthopedic implants.
近年来，由于各种可生物降解镁合金具有合适的机械性能、生物降解性和良好的生物相容性，它们已得到开发。在本研究中，制备了Mg-2.0Zn-Gd合金（=0.5、1.0、1.5和2.0 wt%）。采用热挤压以细化微观结构并提高耐降解性。首先研究了Mg-2.0Zn-Gd合金的微观结构、机械性能和体外降解行为。挤压态Mg-2.0Zn-1.0Gd合金表现出优异的机械性能（抗拉强度338 MPa、屈服强度284 MPa、伸长率24%）和较低的体外降解速率（0.24 mm/年），降解形态均匀，然后，选择该合金进行进一步评估。发现挤压态Mg-2.0Zn-1.0Gd合金对MC3T3-E1细胞的细胞毒性为0-1级，表明其具有良好的生物相容性。体内实验表明，将该合金植入Sprague-Dawley大鼠颅骨缺损30天后，其体内降解速率约为0.31 mm/y。所有这些都表明Mg-2.0Zn-1.0Gd合金作为生物可降解应用，特别是作为骨科植入物具有广阔的前景。
