Experimental Physics, Saarland University, Saarbrücken, Germany.
Laboratoire Interdisciplinaire de Physique, Saint Martin d'Hères, France.
Microcirculation. 2021 Jul;28(5):e12693. doi: 10.1111/micc.12693. Epub 2021 Mar 18.
Knowledge about the flow field of the plasma around the red blood cells in capillary flow is important for a physical understanding of blood flow and the transport of micro- and nanoparticles and molecules in the flowing plasma. We conducted an experimental study on the flow field around red blood cells in capillary flow that is complemented by simulations of vortical flow between red blood cells.
Red blood cells were injected in a 10 × 12 µm rectangular microchannel at a low hematocrit, and the flow field around one or two cells was captured by a high-speed camera that tracked 250 nm nanoparticles in the flow field, acting as tracers.
While the flow field around a steady "croissant" shape is found to be similar to that of a rigid sphere, the flow field around a "slipper" shape exhibits a small vortex at the rear of the red blood cell. Even more pronounced are vortex-like structures observed in the central region between two neighboring croissants.
The rotation frequency of the vortices is to a good approximation, inversely proportional to the distance between the cells. Our experimental data are complemented by numerical simulations.
了解红细胞在毛细血管流动中的等离子体流场，对于理解血流以及流动等离子体中微纳米粒子和分子的输运具有重要意义。我们对毛细血管中红细胞周围的流场进行了实验研究，并通过红细胞间的涡旋流模拟对其进行了补充。
以低血细胞比容将红细胞注入 10×12μm 的矩形微通道中，并通过高速摄像机捕获一个或两个细胞周围的流场，流动场中的 250nm 纳米粒子作为示踪剂。
稳态“新月形”红细胞周围的流场与刚性球体相似，而“拖鞋形”红细胞周围的流场在红细胞尾部出现小涡旋。在两个相邻的新月形之间的中心区域观察到更明显的类涡旋结构。
涡旋的旋转频率与细胞之间的距离呈良好的反比关系。我们的实验数据得到了数值模拟的补充。
