Potential biodegradable Zn-Cu binary alloys developed for cardiovascular implant applications
Potential biodegradable Zn-Cu binary alloys developed for cardiovascular implant applications
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DOI：
10.1016/j.jmbbm.2017.05.013
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发表时间：
2017-08-01
影响因子：
3.9
通讯作者：
Yuan, Guangyin
中科院分区：
文献类型：
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作者：
Tang, Zibo;Niu, Jialin;Yuan, Guangyin
二元锌铜合金体系是一种具有潜在生物降解性能的心血管植入材料。系统研究了挤压态锌铜(x=1、2、3和4wt%)合金的显微组织、拉伸性能、体外腐蚀行为、细胞毒性和抗菌性能。结果表明，随着铜含量的增加，CuZn5相的析出量增加。挤压后，合金中的CuZn5相断裂，细化了合金的晶粒。拉伸试验表明，铜的加入可以显著提高锌铜合金的力学性能。其中，锌铜的延伸率达到了50.6+/-2.8%，这为支架的微管加工提供了便利。用锌铜二元合金成功地制备了外径3 mm、厚度0.2 mm的微管和血管支架。锌铜合金在c-SBF溶液中的降解速率很低，从22.1+/-4.7到33.0+/-1.0亩/年(-1)。随着铜含量的增加，锌-x铜合金的腐蚀速率总体上比纯锌略有增加，但没有显著差异。体外实验表明，锌铜合金对人血管内皮细胞有较好的细胞毒性，当铜浓度大于2wt%时，抗菌性能(金黄色葡萄球菌)最好。因此，新开发的锌铜二元合金具有良好的强度和延展性、低的降解率、可接受的细胞毒性和良好的抗菌性能，有望成为可生物降解的心血管植入物的候选材料。
Binary Zn-Cu alloy system is developed as potential biodegradable materials for cardiovascular implant application. The microstructure, tensile properties, in vitro corrosion behavior, cytotoxicity and antibacterial property of as-extruded Zn-xCu (x= 1, 2, 3, and 4 wt%) alloys are investigated systematically. It shows that as Cu content increases more CuZn5 phase precipitates. After extrusion, the CuZn5 phases are broken and the grains of Zn-xCu alloys are refined. Tensile test shows that Cu addition could significantly improve the mechanical properties of Zn-xCu alloys. Particularly, the elongation of the Zn-4Cu reaches 50.6 +/- 2.8%, which could facilitate the micro-tubes processing for stent fabrication. The micro-tubes of 3 mm in outer diameter and 0.2 mm in thickness as well as vascular stents have been fabricated successfully using the Zn-Cu binary alloy. The degradation rates of Zn-xCu alloys in c-SBF solution are quite low, which vary from 22.1 +/- 4.7 to 33.0 +/- 1.0 mu m year(-1). With increasing Cu concentration, the corrosion rates of the Zn-xCu alloys generally exhibit a little increase compared with pure Zn, which show no significant difference among Zn-xCu alloys. In vitro test shows that Zn-xCu alloys exhibit acceptable cytotoxicity to human endothelial cells and the antibacterial property (S. aureus) is perfect when Cu concentration is higher than 2 wt%. Therefore, the newly developed Zn-xCu binary alloys could be promising candidates for biodegradable cardiovascular implant application due to their excellent combination of strength and ductility, low degradation rates, acceptable cytotoxicity and good antibacterial property.