Gagliardi Mariacristina
NEST, Istituto Nanoscienze-CNR, Piazza San Silvestro 12, Pisa 56127, Italy.
Med Eng Phys. 2020 Aug;82:78-85. doi: 10.1016/j.medengphy.2020.06.004. Epub 2020 Jul 9.
Since theoretical models provide data that cannot be otherwise gathered, numerical methods applied to medical devices analysis have emerged as fundamental tool in preclinical development. Large efforts were done to study mechanical and drug-eluting properties in stents but often the coating modelling is neglected. This work presents a finite element framework to calculate mechanical loads and drug distribution in three commercial drug-eluting stents (Palmaz-Schatz, Palmaz Genesis and Multi Link Vision), to check coatings strength and drug distribution maps in biological tissues. The promising copolymer poly(methylmethacrylate-co-n-butylmethacrylate), loaded with paclitaxel, is analyzed. Results demonstrated that the coating undergoes localized plastic phenomena, and calculated stresses are lower than the ultimate stress, ensuring coating integrity. Computed drug concentration depends on stent geometry and its values are in all cases lower than the toxicity level for this drug.
由于理论模型提供了无法通过其他方式收集的数据，应用于医疗设备分析的数值方法已成为临床前开发的基本工具。人们在研究支架的力学和药物洗脱特性方面付出了巨大努力，但涂层建模往往被忽视。这项工作提出了一个有限元框架，用于计算三种商业药物洗脱支架（Palmaz-Schatz、Palmaz Genesis和Multi Link Vision）中的机械载荷和药物分布，以检查生物组织中的涂层强度和药物分布图。对负载紫杉醇的有前景的共聚物聚（甲基丙烯酸甲酯-共-正丁基丙烯酸甲酯）进行了分析。结果表明，涂层会发生局部塑性现象，计算出的应力低于极限应力，确保了涂层的完整性。计算出的药物浓度取决于支架的几何形状，并且在所有情况下其值都低于该药物的毒性水平。
