Emergent cell-free layer asymmetry and biased haematocrit partition in a biomimetic vascular network of successive bifurcations.
Emergent cell-free layer asymmetry and biased haematocrit partition in a biomimetic vascular network of successive bifurcations.
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DOI：
10.1039/d0sm01845g
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发表时间：
2021-01
期刊：
影响因子：
3.4
通讯作者：
Qi Zhou;J. Fidalgo;M. Bernabeu;Mónica S. A. Oliveira;T. Krüger
中科院分区：
文献类型：
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作者：
Qi Zhou;J. Fidalgo;M. Bernabeu;Mónica S. A. Oliveira;T. Krüger
血液是一种重要的软物质，其在人体内的正常循环依赖于红细胞（RBC）在连续分叉处的分布。了解红细胞如何在分叉处被分割是优化微流体装置以及设计诊断和治疗血液相关疾病的新策略的关键。我们报告的动力学的红细胞悬浮液流经仿生血管网络，包括三代微通道和两个经典类型的分叉在微动脉水平。我们的微流控实验与稀释和半稀释红细胞悬浮液表明，在下游几代的红细胞浓度的过度异质性的出现后，改变网络的流出速率。通过使用浸没边界格子Boltzmann方法的并行模拟，我们揭示了非均匀性是由于上游扰动的无细胞层（CFL）和缺乏其恢复之间的连续分叉，由于抑制流体动力升力在减少流量条件下。在稀释/半稀释状态下，这种扰动在分叉处的局部分流效应上占主导地位，并且可能导致即使对于相等的流量分流也被剥夺RBC的固有不利的子分支。我们的工作突出了CFL不对称级联的血管网络，这导致偏离既定的经验预测偏相分离的重要性。
Blood is a vital soft matter, and its normal circulation in the human body relies on the distribution of red blood cells (RBCs) at successive bifurcations. Understanding how RBCs are partitioned at bifurcations is key for the optimisation of microfluidic devices as well as for devising novel strategies for diagnosis and treatment of blood-related diseases. We report the dynamics of RBC suspensions flowing through a biomimetic vascular network incorporating three generations of microchannels and two classical types of bifurcations at the arteriole level. Our microfluidic experiments with dilute and semidilute RBC suspensions demonstrate the emergence of excessive heterogeneity of RBC concentration in downstream generations upon altering the network's outflow rates. Through parallel simulations using the immersed-boundary-lattice-Boltzmann method, we reveal that the heterogeneity is attributed to upstream perturbations in the cell-free layer (CFL) and lack of its recovery between consecutive bifurcations owing to suppressed hydrodynamic lift under reduced flow conditions. In the dilute/semidilute regime, this perturbation dominates over the effect of local fractional flow at the bifurcation and can lead to inherently unfavourable child branches that are deprived of RBCs even for equal flow split. Our work highlights the importance of CFL asymmetry cascading down a vascular network, which leads to biased phase separation that deviates from established empirical predictions.