Biodegradable Zn-Cu-Mn alloy with suitable mechanical performance and in vitro degradation behavior as a promising candidate for vascular stents
Biodegradable Zn-Cu-Mn alloy with suitable mechanical performance and in vitro degradation behavior as a promising candidate for vascular stents
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DOI：
10.1016/j.msec.2022.112652
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发表时间：
2022-02-01
影响因子：
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通讯作者：
Yuan, Guangyin
中科院分区：
文献类型：
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作者：
Jiang, Jimiao;Qian, Yi;Yuan, Guangyin
近年来，锌合金因其良好的生理可降解性和良好的生物相容性而被认为是一种很有前途的生物降解材料。然而，较差的机械性能限制了其作为血管支架的应用。本文研究了具有良好力学性能的新型可生物降解的Zn-2.2Cu-xMn(x=0.4、0.7和1.0wt%)合金。系统研究了添加Mn对Zn-2.2Cu-xMn合金的显微组织、力学性能和体外降解的影响。加入Mn后，促进了热挤压过程中的动态再结晶(DRX)，使热挤压后的动态再结晶(DRX)晶粒度略有细化，DRXed区域比增大，织构减弱。第二相析出物(微米、亚微米和纳米尺寸的e相和MnZn13相)的体积分数和数密度增加，(Cu，Mn)在基体中的浓度增加。因此，由于晶粒细化、固溶强化、第二相沉淀硬化和织构弱化的综合作用，锌2.2Cu-xMn合金具有较好的力学性能(强度和伸长率分别为310 Mpa和30%)。此外，合金在18个月内保持了良好的力学性能稳定性，即使在0.1S(？)(-1)的高应变率下也保持了良好的延伸率在15%以上。此外，合金在体外具有合适的降解速率，降解模式基本均匀，体外细胞相容性良好。以上结果表明，新设计的可生物降解的Zn-2.2Cu-0.4Mn合金具有合适的综合力学性能、合适的降解行为和良好的细胞相容性，是一种很有前途的血管支架候选材料。
Recently, zinc (Zn) alloy has been considered as a promising biodegradable material due to its excellent physiological degradable behavior and acceptable biocompatibility. However, poor mechanical performance limits its application as vascular stents. In this study, novel biodegradable Zn-2.2Cu-xMn (x= 0.4, 0.7, and 1.0 wt%) alloys with suitable mechanical performance were investigated. The effects of Mn addition on microstructure, mechanical properties, and in vitro degradation of Zn-2.2Cu-xMn alloys were systematically investigated. After adding Mn, dynamic recrystallization (DRX) during hot extrusion was promoted, resulting in slightly finer grain size, higher DRXed regions ratio, and weaker texture. And volume fraction and number density of second phase precipitates (micron, submicron, and nano-sized e and MnZn13 phase) and the concentration of (Cu, Mn) in the matrix were increased. Therefore, Zn2.2Cu-xMn alloys exhibited suitable mechanical performances (strength >310 MPa, elongation >30%) mainly due to the combination effects of grain refinement, solid solution strengthening, second phase precipitation hardening, and texture weakening. Moreover, the alloys maintained good stability of mechanical properties within 18 months and good elongation over 15% even at a high strain rate of 0.1 s(.)(-1) In addition, the alloys presented appropriate in vitro degradation rates in a basically uniform degradation mode and acceptable in vitro cytocompatibility. The above results indicated that the newly designed biodegradable Zn-2.2Cu-0.4Mnalloy with suitable comprehensive mechanical properties, appropriate degradation behavior, and acceptable cytocompatibility is a promising candidate for vascular stents.