可降解Zn-Mg和Zn-Ca合金的长期体内降解规律、成骨反应及生物安全性研究

Two classes of biodegradable metallic materials have been widely investigated in the past two decades: Mg-based and Fe-based alloys. However, regarding to the clinical requirements, studies have found that biodegradable Mg-based alloys have too fast degradation rate. On the contrary, Fe-based alloys have too slow degradation rate. Compared with the abovementioned biodegradable Mg-based and Fe-based alloys, Zn-based alloys have more suitable degradation rates, which are faster than Fe-based alloys while slower than Mg-based alloys. Therefore, Zn-based alloys have recently been studied and considered as a novel kind of biodegradable metallic materials for biomedical applications. Unfortunately, the research on biodegradable Zn-based alloys is still in its infancy. The majority of the research is focused on the in vitro properties, such as microstructure, mechanical properties, in vitro corrosion behavior and in vitro cytotoxicity etc. While the in vivo performances of biodegradable Zn-based alloys are rarely studied. The present project aims to design and develop Zn-1Mg and Zn-1Ca bone screws and implant these screws into the femoral condyle of New Zealand white rabbit, and study the long term in vivo biodegradation, osteogenesis response and biological safety of biodegradable Zn-Mg and Zn-Ca alloys. The mechanism of the long term in vivo degradation behavior and osteogenesis response of biodegradable Zn-Mg and Zn-Ca alloys will be explored and clarified. The changes of the mechanical properties of the Zn-Mg and Zn-Ca screws with different implantation period will be investigated. The effect and mechanism of different alloying elements (Mg, Ca) and different microstructure of Zn-Mg and Zn-Ca screws on the biodegradation behavior, biomechanical properties and bone tissue healing will be further studied and expounded. The present project will provide experimental data and evidence for the further development of new biodegradable Zn-based alloys with controllable degradation rate and satisfactory performance for orthopaedic applications.

可降解锌合金（Zn合金）因其腐蚀速率介于可降解镁合金和可降解铁合金之间，有望解决可降解镁合金与铁合金与临床需求不相匹配的腐蚀速率问题，成为新一代的生物医用可降解合金。目前可降解锌合金的研究尚处于起步阶段，多数集中于锌合金的体外性能研究，而关于其体内性能的研究则相对较少。本项目拟设计并制备新型生物医用可降解锌合金（Zn-1Mg和Zn-1Ca）骨螺钉，植入新西兰大白兔股骨髁，研究新型生物医用可降解Zn合金的长期体内降解规律、成骨反应及生物安全性，综合评价新型生物医用可降解Zn合金的长期体内安全性和有效性，阐明新型生物医用可降解Zn合金在生物体环境下的降解机制、成骨作用、力学性能随时间变化、生物安全性及相关影响因素，揭示可降解医用Zn合金的不同成分(Mg, Ca)、组织结构对其生物降解、生物力学和骨组织愈合的影响规律，为发展出满足临床性能需求和可控降解的骨科用可降解Zn合金提供实验依据。

可降解锌合金（Zn合金）因其腐蚀速率介于可降解镁合金和可降解铁合金之间，有望解决可降解镁合金与铁合金与临床需求不相匹配的腐蚀速率问题，成为新一代的生物医用可降解合金。目前可降解锌合金的研究尚处于起步阶段，多数集中于锌合金的体外性能研究，而关于其体内性能的研究则相对较少。本项目设计并制备新型生物医用可降解锌合金（Zn-1Mg和Zn-1Ca）骨螺钉，植入新西兰大白兔股骨髁，研究新型生物医用可降解Zn合金的长期体内降解规律、成骨反应及生物安全性，综合评价了新型生物医用可降解Zn合金的长期体内安全性和有效性，阐明了新型生物医用可降解Zn合金在生物体环境下的降解机制、成骨作用、力学性能随时间变化、生物安全性及相关影响因素，揭示了可降解医用Zn合金的不同成分(Mg, Ca)、组织结构对其生物降解、生物力学和骨组织愈合的影响规律，为发展出满足临床性能需求和可控降解的新型生物医用可降解Zn合金提供了相关实验数据与理论依据。目前，正在积极推动项目相关成果的转化及应用，相关产品通过伦理审批，正在开展大动物实验和临床预实验，预计5-10内实现可降解锌合金医疗器械的临床应用与转化。依托本项目，培养博士生2名，硕士生3名；依托本项目，课题负责人成功入选第四届中国科协青年人才托举工程（2019年1月）。项目成果主要包括5篇SCI/EI收录论文，申请5项国际/国内发明专利，其中3项授权，受邀做国内外会议报告10余次。