Boundary integral simulations of a red blood cell squeezing through a submicron slit under prescribed inlet and outlet pressures
Boundary integral simulations of a red blood cell squeezing through a submicron slit under prescribed inlet and outlet pressures
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DOI：
10.1063/1.5081057
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发表时间：
2019-11
影响因子：
4.6
通讯作者：
Zhangli Peng;Huijie Lu;Alexis Moreau;E. Helfer;A. Charrier;A. Viallat
中科院分区：
文献类型：
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作者：
Zhangli Peng;Huijie Lu;Alexis Moreau;E. Helfer;A. Charrier;A. Viallat
我们发展了一个边界积分公式来模拟在给定的入口和出口压力下红细胞(RBC)通过亚微米狭缝的挤压。这项计算研究的主要应用是研究红细胞和相应的体外模拟微流控装置的脾滤过，在此过程中红细胞有规律地通过宽度小于1μm的内皮间缝隙，在这个机械过滤过程中，病变的和陈旧的红细胞被损坏或破坏。我们首先推导了在给定的入口和出口压力下，浸入受限区域的RBC的边界积分方程组。我们应用了统一的自适应求积来精确地计算奇异积分和近奇异积分，这在强润滑的流固耦合问题中尤为重要。采用多尺度模型计算红细胞膜的作用力，并将其耦合到边界积分方程组来模拟流固耦合。经过多步验证和与分析和实验结果的对比，我们系统地研究了压降、体积表面积比、内粘度和膜刚度对红细胞变形和内应力的影响。我们发现，红细胞的光谱蛋白在高流体动压下可以被拉伸2.5倍以上，双层张力可以超过500pN/μm，它可能大到足以打开机械敏感通道，但太小而不能破坏双层。另一方面，我们发现双层-细胞骨架解离应力太低，不能诱导双层囊泡形成。由AIP出版公司授权出版。Https://doi.org/10.1063/1.5081057
We developed a boundary integral formulation to simulate a red blood cell (RBC) squeezing through a submicron slit under prescribed inlet and outlet pressures. The main application of this computational study is to investigate splenic filtrations of RBCs and the corresponding in vitro mimicking microfluidic devices, during which RBCs regularly pass through inter-endothelial slits with a width less than 1.0 μm. The diseased and old RBCs are damaged or destroyed in this mechanical filtration process. We first derived the boundary integral equations of a RBC immersed in a confined domain with prescribed inlet and outlet pressures. We applied a unified self-adaptive quadrature to accurately evaluate singular and nearly singular integrals, which are especially important in this fluid-structure interaction problem with strong lubrication. A multiscale model is applied to calculate forces from the RBC membrane, and it is coupled to boundary integral equations to simulate the fluid-structure interaction. After multi-step verifications and validations against analytical and experimental results, we systematically investigated the effects of pressure drop, volume-to-surface-area ratio, internal viscosity, and membrane stiffness on RBC deformation and internal stress. We found that spectrins of RBCs could be stretched by more than 2.5 times under high hydrodynamic pressure and that the bilayer tension could be more than 500 pN/μm, which might be large enough to open mechanosensitive channels but too small to rupture the bilayer. On the other hand, we found that the bilayer-cytoskeletal dissociation stress is too low to induce bilayer vesiculation. Published under license by AIP Publishing. https://doi.org/10.1063/1.5081057