School of Mechanical Engineering, Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing, 211189, China.
School of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, 210037, China.
Med Eng Phys. 2020 Jul;81:118-124. doi: 10.1016/j.medengphy.2020.04.006. Epub 2020 May 12.
Poly(L-lactic acid) (PLLA) is currently the bioresorbable polymer of choice for vascular stents with its superior biocompatibility and mechanical properties. However, it is still difficult to enhance the radial supporting capacity of PLLA stents without increasing the strut thickness. In this study, the performance of laser-cut thin-strut stents from two groups of PLLA tubes are investigated. We considered two groups of PLLA tubes. Group 1 indicates the longitudinally stretched from original 150-μm-thick tubes, and Group 2 indicates the directly thinned from original 150-μm-thick tubes. Three stages of mechanical tests were conducted in this study, which are defined as tensile tests of dog-bone specimens, radial loading tests of tubes and radial loading tests of stents. The results suggest that Group 2 has higher radial supporting capacity than Group 1 with the same wall thickness. This work serves as a basis for manufacturing thin-strut stents with sufficient radial supporting capacity.
聚（L-乳酸）（PLLA）目前是血管支架中首选的可生物降解聚合物，具有优异的生物相容性和机械性能。然而，在不增加支柱厚度的情况下，仍然难以提高 PLLA 支架的径向支撑能力。在这项研究中，我们研究了两组 PLLA 管激光切割的薄壁支架的性能。我们考虑了两组 PLLA 管。第 1 组表示从原始的 150-μm 厚管纵向拉伸而来，第 2 组表示从原始的 150-μm 厚管直接减薄而来。本研究进行了三个阶段的机械测试，分别定义为狗骨试件的拉伸测试、管的径向加载测试和支架的径向加载测试。结果表明，在相同壁厚的情况下，第 2 组比第 1 组具有更高的径向支撑能力。这项工作为制造具有足够径向支撑能力的薄壁支架奠定了基础。
