Wang Zhenze, Sun Anqiang, Fan Yubo, Deng Xiaoyan
Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
Biorheology. 2012;49(4):249-59. doi: 10.3233/BIR-2012-0607.
To elucidate the difference between Newtonian and shear thinning non-Newtonian assumptions of blood in the analysis of DES drug delivery, we numerically simulated the local flow pattern and the concentration distribution of the drug at the lumen-tissue interface for a structurally simplified DES deployed in a curved segment of an artery under pulsatile blood flow conditions. The numerical results showed that when compared with the Newtonian model, the Carreau (shear thinning) model could lead to some differences in the luminal surface drug concentration in certain areas along the outer wall of the curved vessel. In most areas of the vessel, however, there were no significant differences between the 2 models. Particularly, no significant difference between the two models was found in terms of the area-averaged luminal surface drug concentration. Therefore, we believe that the shear thinning property of blood may play little roles in DES drug delivery. Nevertheless, before we draw the conclusion that Newtonian assumption of blood can be used to replace its non-Newtonian one for the numerical simulation of drug transport in the DES implanted coronary artery, other more complex mechanical properties of blood such as its thixotropic behavior should be tested.
为了阐明在药物洗脱支架（DES）药物递送分析中，血液的牛顿流体假设和剪切变稀非牛顿流体假设之间的差异，我们在脉动血流条件下，对部署在动脉弯曲段的结构简化的DES，在管腔-组织界面处的局部流动模式和药物浓度分布进行了数值模拟。数值结果表明，与牛顿流体模型相比，卡雷奥（剪切变稀）模型可能会导致在弯曲血管外壁某些区域的管腔表面药物浓度出现一些差异。然而，在血管的大多数区域，这两种模型之间没有显著差异。特别是，在管腔表面药物浓度的面积平均值方面，两种模型之间没有发现显著差异。因此，我们认为血液的剪切变稀特性在DES药物递送中可能作用不大。尽管如此，在我们得出可以用血液的牛顿流体假设来替代其非牛顿流体假设，用于植入冠状动脉的DES中药物传输的数值模拟这一结论之前，血液的其他更复杂的力学性质，如触变性行为，应该进行测试。
