Nguyen T Y, Cipriano A F, Guan Ren-Guo, Zhao Zhan-Yong, Liu Huinan
Department of Bioengineering, University of California at Riverside, 900 University Avenue, Riverside, California, 92521.
Materials Science and Engineering Program, University of California at Riverside, 900 University Avenue, Riverside, California, 92521.
J Biomed Mater Res A. 2015 Sep;103(9):2974-86. doi: 10.1002/jbm.a.35429. Epub 2015 Mar 11.
Magnesium (Mg) alloy is an attractive class of metallic biomaterial for cardiovascular applications due to its biodegradability and mechanical properties. In this study, we investigated the degradation in blood, thrombogenicity, and cytocompatibility of Magnesium-Zinc-Strontium (Mg-Zn-Sr) alloys, specifically four Mg-4 wt % Zn-xSr (x = 0.15, 0.5, 1, and 1.5 wt %) alloys, together with pure Mg control and relevant reference materials for cardiovascular applications. Human whole blood and platelet rich plasma (PRP) were used as the incubation media to investigate the degradation behavior of the Mg-Zn-Sr alloys. The results showed that the PRP had a greater pH increase and greater concentration of Mg(2+) ions when compared with whole blood after 2 h of incubation with the same respective Mg alloys, suggesting that the Mg alloys degraded faster in PRP than in whole blood. The Mg alloy with 4 wt % Zn and 0.15 wt % Sr (named as ZSr41A) was identified as the most promising alloy for cardiovascular stent applications, because it showed slower degradation and less thrombogenicity, as indicated by the lower concentrations of Mg(2+) ions released and less deposition of platelets. Additionally, ZSr41 alloys were cytocompatible with fibroblasts in direct exposure culture in which the cells adhered and proliferated around the samples, with no statistical difference in cell adhesion density compared with the blank reference. Future studies on the ZSr41 alloys are necessary to investigate their direct interactions with other important cells in cardiovascular system, such as vascular endothelial cells and smooth muscle cells.
镁（Mg）合金由于其生物可降解性和机械性能，是一类用于心血管应用的有吸引力的金属生物材料。在本研究中，我们研究了镁锌锶（Mg-Zn-Sr）合金，特别是四种Mg-4 wt%Zn-xSr（x = 0.15、0.5、1和1.5 wt%）合金在血液中的降解、血栓形成性和细胞相容性，同时还有纯镁对照以及心血管应用的相关参考材料。使用人全血和富含血小板血浆（PRP）作为孵育介质来研究Mg-Zn-Sr合金的降解行为。结果表明，与相同的Mg合金孵育2小时后，PRP的pH值升高幅度更大，Mg(2+)离子浓度更高，这表明Mg合金在PRP中的降解速度比在全血中更快。含4 wt%Zn和0.15 wt%Sr的Mg合金（命名为ZSr41A）被确定为最有前途的心血管支架应用合金，因为它显示出较慢的降解和较低的血栓形成性，这表现为释放的Mg(2+)离子浓度较低且血小板沉积较少。此外，ZSr41合金在直接暴露培养中与成纤维细胞具有细胞相容性，细胞在样品周围粘附并增殖，与空白对照相比，细胞粘附密度无统计学差异。有必要对ZSr41合金进行进一步研究，以探讨它们与心血管系统中其他重要细胞，如血管内皮细胞和平滑肌细胞的直接相互作用。
