生物医用锌基合金性能研究进展

Research Progress on Properties of Biomedical Degradable Zinc-based Alloys

医用金属植入体已广泛应用于临床骨组织修复中,但是随着临床手术案例的积累,发现不锈钢、钛、传统生物金属材料在生物体内长期存在会造成应力屏蔽、组织排异发炎等症状,二次手术会给患者带来极大痛苦。近年来,可降解金属植入体材料的概念被提出并引起重视,由可降解金属制备的植入体在生物体组织中可被吸收分解,并促进血管组织愈合与骨组织再生,被视为新一代医用植入体材料。锌合金由于其优异的降解特性及生物相容性成为近年来的研究热点,在血管腔内支架、骨科及口腔科内固定材料领域拥有巨大的应用潜力。锌合金发展迅速,须及时进行全面总结。总结归纳目前医用锌合金的主要制备方式、材料力学性能、降解行为和生物相容性。基于大量的数据分析与归纳,发现在锌合金中添加Li、Mg元素可细化晶粒,显著提高锌合金强度,添加Mn元素则可在塑性变形中细化晶粒,可提高锌合金的延伸率。与纯锌相比,锌合金中的Zn-(Fe、Cu、Ag)析出相与Zn基体形成的微电池作用提高了锌合金的降解速率。针对新型锌合金成分及先进制备工艺,提出以材料基因工程,指导适用于增材制造的三元高强锌合金体系开发,在提高力学性能的基础上匹配锌合金的降解速率和生物相容性,直接获得具有定制化结构的锌合金近终成型植入体。在系统性汇总的基础上,从性能、开发以及增材制造三个方面展望未来发展方向。

Medical metal implants have been widely used in the clinical bone tissue repair field.However,with the accumulation of clinical operation cases.It is found that the long-term existence of traditional biomaterials such as stainless steel,titanium and tantalum in human body will cause some symptoms such as stress shielding,tissue rejection and inflammation while secondary operation will bring excruciating agonies to patients.The concept of absorbable metal for implant has been proposed and attracted attention.Absorbable metals have the potential to serve as the next generation of temporary medical implant devices by safely dissolving in the human body and promoting vascular tissue healing and bone regeneration.Zn-based alloy havs been a research hotspot because of its excellent biocompatibility and suitable degradation behavior.And,it has great application potential in the fields of cardiovascular stents and orthopedic fixation materials.The rapid development of Zn-Based alloys research requires a comprehensive summary in time.Therefore,the main preparation methods,mechanical properties,degradation behavior and biocompatibility of biodegradable Zn-Based alloys are summarized.Based on the analysis of abundant data,it can be found that the addition of Li and Mg in zinc alloy can refine the grain and significantly improve the strength of zinc alloy,while adding Mn can refine the grain in plastic deformation,which plays a certain role in improving the elongation of zinc alloy.The degradation rate of zinc alloy is higher than pure zinc because that Zn-(Fe,Cu,Ag)x precipitated phase could form a micro cell with Zn matrix.In order to improve the mechanical properties of zinc alloy while matching degradation rate and biocompatibility,this paper proposes to design the multicomponent high strength zinc alloy system guided by Materials Genome Initiative and directly obtain implants with customized structure by additive manufacturing.Based on the systematic summary,the future development direction is prospected from three aspects:performance,material development and additive manufacturing.