摘要
可降解医用镁合金在骨科领域显示出良好的应用前景.为了保证镁合金的生物相容性,本文设计了全营养元素组成的Mg-Zn-Ca合金,研究了其体内外腐蚀及生物相容性.Mg-Zn-Ca合金在五种模拟体液中的腐蚀测试结果表明在Hank’s和MEM中添加血清能够降低合金腐蚀速度,并提高腐蚀均匀性.血清浓度越高,合金腐蚀速率越低.Mg-Zn-Ca合金在MEM+10%FBS溶液中腐蚀速率低,腐蚀形貌均匀.直接法和间接法的细胞实验结果均显示Mg-Zn-Ca合金具有良好的细胞相容性.动物实验结果表明,Mg-Zn-Ca合金在小鼠骨髓腔内逐步降解,4周后残余40 vol.%.micro-CT和组织学观察显示植入体周围有新骨形成,且随着植入时间延长,皮质骨厚度增加.因此,挤压态Mg-Zn-Ca合金具有良好的生物相容性,有望用作骨科植入材料,但是其体内降解速率还应进一步降低.
Magnesium alloys have shown prospective applications as a new biodegradable metal within bone. To garantee the longterm biocompatibility, a Mg-Zn-Ca alloy,composing of essential elements for human, was prepared and its feasibility for orthopedic applications was investigated. The in vitro and in vivo corrosion of Mg-Zn-Ca alloy as well as the biocompatibility were studied. The in vitro corrosion tests in five kinds of physiological solutions showed that the corrosion rates and corrosion morphologies of the alloy were strongly influenced by the solution used. The addition of serum in Hank’s and MEM significantly slowed down the corrosion rate and improved the corrosion uniformity of the alloy. The corrosion rate decreased with increasing serum concentration.The alloy showed the slowest corrosion rate as well as homogeneous corrosion morphology in MEM＋10%FBS. Both the indirect and direct cell experiments indicated good cytocompatibility of the extruded Mg-Zn-Ca alloy. In vivo, we observed a gradual degradation process from the surface of extruded Mg-Zn-Ca alloy and only 40% in volume of implant was left after 4 weeks implantation in medullary cavities of mice. The micro-CT and histological analyses revealed its good biocompatibility with peri-implant new bone formation and increasing cortical bone thickness with increasing implantation period. This study showed that the extruded MgZn-Ca alloy provided sufficient biocompatibility for orthopedic application, though the in vivo corrosion rate should be further reduced for clinical use.
作者
顾雪楠
王凡
谢鑫荟
郑明毅
李萍
郑玉峰
秦岭
樊瑜波
Xuenan Gu;Fan Wang;Xinhui Xie;Mingyi Zheng;Ping Li;Yufeng Zheng;Ling Qin;Yubo Fan(School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China;Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing 102402, China;Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China;School of Materials science and Engineering, Harbin Institute of Technology, Harbin 150001, China;Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China;National Research Center for Rehabilitation Technical Aids, Beijing 100176, China)
基金
supported by the National Natural Science Foundation of China(51401007,11472032,11120101001 and 11421202)
a foundation for the author of the National Excellent Doctoral Dissertation of China(201463)
Young Elite Scientists Sponsorship Program By CAST(2017QNRC001)
the National Key Research and Development Plan(2016YFC1102203 and 2016YFC1101100)
