Gu Xue-Nan, Lu Yun, Wang Fan, Lin Wenting, Li Ping, Fan Yubo
Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 10083, China.
Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, 102402, China.
Bioact Mater. 2018 Sep 1;3(4):448-454. doi: 10.1016/j.bioactmat.2018.08.002. eCollection 2018 Dec.
Magnesium alloys have gained great attention as biodegradable materials for stent applications. Cardiovascular stents are continuously exposed to different types of mechanical loadings simultaneously during service, including tensile, compressive and fluid shear stress. In this study, the in vitro degradation of WE43 wires was investigated under combined effect of tensile loading and fluid shear stress and compared with that experienced an individual loading condition. For the individual mechanical loading treatment, the degradation of magnesium wires was more severely affected by tensile loading than fluid shear stress. Under tensile loading, magnesium wires showed faster increment of corrosion rates, loss of mechanical properties and localized corrosion morphology with the increasing tensile loadings. With the combined stress, smaller variation of the corrosion rates as well as the slower strength degeneration was shown with increasing stress levels, in comparison with the individual treatment of tensile loading. This study could help to understand the effect of complex stress condition on the corrosion of magnesium for the optimization of biodegradable magnesium stents.
镁合金作为用于支架应用的可生物降解材料受到了广泛关注。心血管支架在服役期间会同时持续受到不同类型的机械载荷作用，包括拉伸、压缩和流体剪切应力。在本研究中，研究了WE43丝材在拉伸载荷和流体剪切应力联合作用下的体外降解情况，并与单独加载条件下的降解情况进行了比较。对于单独的机械加载处理，镁丝的降解受拉伸载荷的影响比流体剪切应力更严重。在拉伸载荷作用下，随着拉伸载荷的增加，镁丝的腐蚀速率增加更快、力学性能损失以及出现局部腐蚀形态。与单独的拉伸载荷处理相比，在联合应力作用下，随着应力水平的增加，腐蚀速率的变化较小，强度退化也较慢。本研究有助于理解复杂应力条件对镁腐蚀的影响，以优化可生物降解镁支架。
