Annu Int Conf IEEE Eng Med Biol Soc. 2021 Nov;2021:4319-4323. doi: 10.1109/EMBC46164.2021.9631074.
Drug-Eluting Stents (DES) are commonly used in Coronary angioplasty procedures to reduce the phenomenon of restenosis. Numerical simulations are proven to be a useful tool to the Bioengineering community in computing the mechanical performance of stents. BioCoStent is a research project aiming to develop a DES with retinoic acid (RA) coating, in the frame of which FEAC is responsible for the in silico numerical simulation of the coating's degradation in terms of Finite Element Analysis (FEA). The coatings under study are poly(lactic-co-glycolic acid) (PLGA) and polylactide (PLA). The FEA is based on the Continuum Damage Mechanics (CDM) theory and considers a mechanistic model for polymer bulk degradation of the coatings. The degradation algorithm is implemented on the NX Nastran solver through a user-defined material UMAT subroutine. This paper describes the developed numerical model to compute the degradation of biodegradable coatings on DES. The transient numerical model provides useful insight into the critical areas with regards to the scalar damage of the coatings. The FEA results present a complete degradation of polymers after several weeks.
药物洗脱支架（DES）常用于经皮冠状动脉介入治疗（PTCA）以减少再狭窄现象。数值模拟已被证明是生物工程界计算支架力学性能的有用工具。BioCoStent 是一个旨在开发载有视黄酸（RA）涂层的 DES 的研究项目，在此项目中，FEAC 负责使用有限元分析（FEA）对涂层的降解进行数值模拟。研究中的涂层为聚（乳酸-共-乙醇酸）（PLGA）和聚乳酸（PLA）。FEA 基于连续损伤力学（CDM）理论，并考虑了涂层的聚合物本体降解的力学模型。降解算法通过用户定义的材料 UMAT 子程序在 NX Nastran 求解器上实现。本文描述了用于计算 DES 上可生物降解涂层降解的开发数值模型。瞬态数值模型提供了有关涂层标量损伤的关键区域的有用见解。FEA 结果表明聚合物在数周后完全降解。
