Kim Jinwoo, Lee Hyeon Ji, Choi Eun Ae, Lee Jung Ho, Oh Jin, Byeon Dae-Heung, Kwak Hyo Sung, Park Chan Hee
Department of Bionanosystem Engineering, Graduate School, Jeonbuk National University, Jeonju 54896, Republic of Korea.
Department of Mechanical Design Engineering, Graduate School, Jeonbuk National University, Jeonju 54896, Republic of Korea; Innovative Mechanobio Active Materials Based Medical Device Demonstration Center, Jeonbuk National University, Jeonju 54896, Republic of Korea.
J Mech Behav Biomed Mater. 2025 Mar;163:106849. doi: 10.1016/j.jmbbm.2024.106849. Epub 2024 Dec 5.
In this study, we propose distinct and novel types of scaffold geometries to improve the mechanical performance of Poly-L-lactic Acid (PLLA) bioresorbable vascular scaffolds (BVS), investigating how different geometries of PLLA BVS influence their mechanical performances through finite element analysis (FEA) and in vitro experiment methods.
Four different types of scaffold geometries were modelled for FEA and manufactured for in vitro experiments. PLLA tubes with 110 μm thickness were used in manufacturing the scaffolds. For FEA measurements, material properties and bilinear material models were obtained from tensile testing using the PLLA tubes employed for manufacturing. Various measurements were conducted including crush resistance, radial strength in both the laser-cut and deployed state, three-point bending, and scaffold crimping/expansion test.
Overall, the FEA results were similar to the experimental results. Design A, which had a conventional open-cell geometry with straight bridges, showed inferior crush resistance and radial strength to those of the other tested geometries. Design B exhibited the most well-balanced scaffold performances in terms of radial strengths, crush resistance, three-point bending, and crimping/expansion behaviors. Notably, it showed minimum plastic strain during crimping and expanding deformations in FEA.
Findings from such distinct and novel types of scaffold geometries shown by this study may provide a valuable understanding using PLLA scaffolds as cardiovascular devices.
在本研究中，我们提出了独特且新颖的支架几何形状类型，以改善聚左旋乳酸（PLLA）生物可吸收血管支架（BVS）的力学性能，通过有限元分析（FEA）和体外实验方法研究不同几何形状的PLLA BVS如何影响其力学性能。
为FEA建模并制造了四种不同类型的支架几何形状用于体外实验。制造支架时使用了厚度为110μm的PLLA管。对于FEA测量，材料性能和双线性材料模型通过使用制造中所用的PLLA管进行拉伸试验获得。进行了各种测量，包括抗压溃性、激光切割和展开状态下的径向强度、三点弯曲以及支架卷曲/扩张试验。
总体而言，FEA结果与实验结果相似。设计A具有带直桥的传统开孔几何形状，其抗压溃性和径向强度低于其他测试几何形状。设计B在径向强度、抗压溃性、三点弯曲和卷曲/扩张行为方面表现出最平衡的支架性能。值得注意的是，在FEA中，它在卷曲和扩张变形过程中显示出最小的塑性应变。
本研究展示的这种独特且新颖的支架几何形状类型的研究结果，可能为将PLLA支架用作心血管装置提供有价值的认识。
