Jafarzadeh Sina, Nasiri Sadr Arsalan, Kaffash Ehsan, Goudarzi Sahar, Golab Ehsan, Karimipour Arash
Department of Chemical and Petroleum Engineering, Sharif University of Technology (SUT), P.O. Box: 11155-1639, Tehran, Iran.
Department of Mechanical and Energy Engineering, Shahid Beheshti University (SBU), P.O. Box: 53571-16589, A.C. Tehran, Iran.
Comput Methods Programs Biomed. 2020 Oct;195:105545. doi: 10.1016/j.cmpb.2020.105545. Epub 2020 May 30.
The present article has simulated to investigate the efficient hemodynamic parameters, the drug persistence, and drug distribution on an abdominal aortic aneurysm.
Blood as a non-Newtonian fluid enters the artery acting as a real pulse waveform; its behavior is dependent on hematocrit and strain rate. In this simulation of computational fluid dynamic, magnetic nanoparticles of iron oxide which were in advance coated with the drug, are injected into the artery during a cardiac cycle. A two-phase model was applied to investigate the distribution of these carriers.
The results are presented for different hematocrits and the nanoparticle diameter. It is observed that hematocrit significantly affects drug persistence, so that lower hematocrit incites more accumulation of the drug in the dilatation part of the artery. The better drug accumulation is noticed, at the higher wall shear stress. Although no considerable impact on the flow pattern and wall shear stress was found with various nanoparticle diameters, the smaller size of the nanoparticles results in a greater amount of drug augmentation in the aneurysm wall output.
At the higher hematocrit levels, the blood resistance to drug delivery increases throughout the artery. Also, the drug accumulates less on the aneurysm wall and stays longer on the aneurysm wall. On the contrary, the drug accumulates more by decreasing hematocrit level and stays shorter on the aneurysm wall. Moreover, the maximum drug concentration is observed at the lowest hematocrit level and nanoparticle diameter; also, the diameter of nanoparticles imposes no significant effect on the vorticity and wall shear stress. It is seen that the increment of the hematocrit level reduces the strength of vorticity and increases the amount of wall shear stress in the dilatation segment of the artery. The shear stress at three points of the dilatation wall is extreme, where the maximum density of nanoparticles occurs.
本文旨在模拟研究腹主动脉瘤的有效血流动力学参数、药物持久性及药物分布情况。
将血液视为非牛顿流体，以真实脉搏波形进入动脉；其行为取决于血细胞比容和应变率。在本次计算流体动力学模拟中，预先包裹药物的氧化铁磁性纳米颗粒在心动周期内注入动脉。应用两相模型研究这些载体的分布情况。
给出了不同血细胞比容和纳米颗粒直径的结果。观察到血细胞比容显著影响药物持久性，较低的血细胞比容会促使药物在动脉扩张部位更多地积聚。在较高的壁面剪应力下，药物积聚效果更佳。尽管不同纳米颗粒直径对血流模式和壁面剪应力没有显著影响，但纳米颗粒尺寸越小，动脉瘤壁输出中的药物增加量越大。
在较高的血细胞比容水平下，血液对药物输送的阻力在整个动脉中增加。此外，药物在动脉瘤壁上的积聚较少，在动脉瘤壁上停留的时间更长。相反，通过降低血细胞比容水平，药物积聚更多，在动脉瘤壁上停留的时间更短。此外，在最低的血细胞比容水平和纳米颗粒直径下观察到最大药物浓度；而且，纳米颗粒直径对涡度和壁面剪应力没有显著影响。可以看出，血细胞比容水平的增加会降低动脉扩张段的涡度强度，并增加壁面剪应力的大小。在扩张壁的三个点处剪应力极大，纳米颗粒密度最大。
