Zhao R, Marhefka J N, Antaki J F, Kameneva M V
McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Biorheology. 2010;47(3-4):193-203. doi: 10.3233/BIR-2010-0570.
The accumulation of platelets near the blood vessel wall or artificial surface is an important factor in the cascade of events responsible for coagulation and/or thrombosis. In small blood vessels and flow channels this phenomenon has been attributed to the blood phase separation that creates a red blood cell (RBC)-poor layer near the wall. We hypothesized that blood soluble drag-reducing polymers (DRP), which were previously shown to lessen the near-wall RBC depletion layer in small channels, may consequently reduce the near-wall platelet excess. This study investigated the effects of DRP on the lateral distribution of platelet-sized fluorescent particles (diam. = 2 μm, 2.5 × 10⁸/ml) in a glass square microchannel (width and depth = 100 μm). RBC suspensions in PBS were mixed with particles and driven through the microchannel at flow rates of 6-18 ml/h with and without added DRP (10 ppm of PEO, MW = 4500 kDa). Microscopic flow visualization revealed an elevated concentration of particles in the near-wall region for the control samples at all tested flow rates (between 2.4 ± 0.8 times at 6 ml/h and 3.3 ± 0.3 times at 18 ml/h). The addition of a minute concentration of DRP virtually eliminated the near-wall particle excess, effectively resulting in their even distribution across the channel, suggesting a potentially significant role of DRP in managing and mitigating thrombosis.
血小板在血管壁或人工表面附近的聚集是导致凝血和/或血栓形成的一系列事件中的一个重要因素。在小血管和流动通道中，这种现象被认为是由于血液相分离，在血管壁附近形成了一个红细胞（RBC）贫乏层。我们推测，先前已证明可减少小通道中近壁红细胞耗尽层的血液可溶性减阻聚合物（DRP），可能因此减少近壁血小板过剩。本研究调查了DRP对玻璃方形微通道（宽度和深度 = 100μm）中血小板大小的荧光颗粒（直径 = 2μm，2.5×10⁸/ml）横向分布的影响。将PBS中的RBC悬浮液与颗粒混合，并在添加和不添加DRP（10 ppm的PEO，分子量 = 4500 kDa）的情况下，以6 - 18 ml/h的流速驱动通过微通道。微观流动可视化显示，在所有测试流速下（6 ml/h时为2.4±0.8倍，18 ml/h时为3.3±0.3倍），对照样品近壁区域的颗粒浓度升高。添加微量浓度的DRP实际上消除了近壁颗粒过剩，有效地使它们在整个通道中均匀分布，这表明DRP在控制和减轻血栓形成方面可能具有重要作用。
