1.Shanghai University of Medicine&2.Health Sciences;3.University of Shanghai for Science and Technology
Shanghai Natural Science Foundation Project（17ZR1413500），School of Medical Instrument and Food Engineering，University of Shanghai for Science and Technology，Minimally Invasive Innovation Fund (YS30810107)
摘要:目的 探究可降解支架在动态降解过程中，血管应力变化对内皮功能恢复以及血管再狭窄抑制作用的影响。方法 拟合超弹性血管本构关系的材料参数，通过数值模拟计算出支架介入前，以及动态降解过程中，血管内膜应力分布；采用体外培养实验，设置硅胶腔体拉伸率分别为0%、5%、10%、15%，以模拟不同降解阶段的力学环境下，探究对内皮细胞生长状态的影响。结果 支架完全降解后血管内膜周向应力（变）恢复到0.137 、5.5%，与支架介入前生理参数（0.122 、4.8%）相接近；体外实验表明在周向应力（变）为0.1 、5%条件下，内皮细胞成活率最高，能实现全部粘附生长。结论 支架随降解进程的发生，内膜周向应力（变）恢复到接近生理参数范围促进了内皮细胞的生长，完整内皮功能的维持有效地抑制了血管再狭窄进程；其结果可为研究冠脉介入治疗血管再狭窄问题，提供理论依据和实验平台。
Abstract: Objective To explore the effect of vascular stress changes on endothelial function recovery and vascular restenosis inhibition, under the condition of dynamic degradation process of the degradable stent. Methods Fitting the material parameters of the hyperelastic vascular constitutive relationship, the stress distribution of the intima of the blood vessel before the stent was implanted and during the dynamic degradation was calculated by numerical simulation. In vitro culture experiments were carried out, and the stretch ratio of the silicon chambers were set to 0%, 5%, 10%, and 15%, respectively, to simulate the effects of different degradation stages on the growth state of endothelial cells. Results After the stent was completely degraded, the circumferential intimal stress (strain) of the vessel was restored to 0.137 , 5.5%, which was close to the physiological parameters (0.122 , 4.8%) before stent implantation. In vitro experiments showed that the endothelial cell survival rate was the highest under the condition of circumferential stress (strain) of 0.1 and 5%, and all adhesion growth could be achieved. Conclusions With the occurrence of degradation process of the stent, the circumferential stress (strain) of the intima was restored to a range close to physiological parameters, which promotes the growth of endothelial cells. The recovery of intimal function can effectively inhibit the process of vascular restenosis. The results can provide a theoretical basis and experimental platform for the study of coronary intervention for the treatment of vascular restenosis.