Influence of Brownian motion on blood platelet flow behavior and adhesive dynamics near a planar wall.
Influence of Brownian motion on blood platelet flow behavior and adhesive dynamics near a planar wall.
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布朗运动对平面壁附近血小板流动行为和粘附动力学的影响。
DOI：
10.1021/la0701475
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
King,MichaelR
中科院分区：
文献类型：
--
作者：
Mody,NipaA;King,MichaelR
我们使用血小板粘附动力学计算方法来研究血小板的布朗运动对其蠕动流态中表面附近的流动特性的影响。在这方面进行了两个重要的表征：（1）通过作用在其上的布朗力和扭矩来量化血小板接触表面的能力，以及（2）确定布朗运动在存在剪切流的情况下促进表面接触的相对重要性。我们确定了在剪切流中经历布朗运动的血小板的佩克莱特数，该数可以表示为血小板质心高度的简单线性函数，H距表面Pe(血小板) = γ̇·(1.56H+ 0.66) for H> 0.3 μm。我们的结果表明，在与血液剪切流相关的时间尺度上，布朗运动在影响血小板运动或为血小板表面接触创造更多机会方面起着微不足道的作用。剪切速率 >100 s-1 时的血小板佩克莱特数足够大 (>200)，足以在动脉和小动脉流动计算模型中忽略血小板布朗运动，以实现大多数实际目的，即使在距表面非常近的距离下也是如此。我们还进行了粘附动力学模拟，以确定血小板布朗运动对 GPIbα-vWF-A1 单键解离动力学的影响。研究发现，布朗运动对键合寿命影响不大，并且键合应力最小，因为键合断裂力经计算小于 0.005 pN。我们从结果中得出结论，对于血小板状细胞，布朗运动预计不会在影响流动特性、血小板表面接触频率和生理剪切速率（> 50 s-1）流动下的解离结合现象方面发挥重要作用。
We used the platelet adhesive dynamics computational method to study the influence of Brownian motion of a platelet on its flow characteristics near a surface in the creeping flow regime. Two important characterizations were done in this regard: (1) quantification of the platelet's ability to contact the surface by virtue of the Brownian forces and torques acting on it, and (2) determination of the relative importance of Brownian motion in promoting surface encounters in the presence of shear flow. We determined the Peclet number for a platelet undergoing Brownian motion in shear flow, which could be expressed as a simple linear function of height of the platelet centroid,Hfrom the surfacePe(platelet) = γ̇·(1.56H+ 0.66) forH> 0.3 μm. Our results demonstrate that at timescales relevant to shear flow in blood Brownian motion plays an insignificant role in influencing platelet motion or creating further opportunities for platelet−surface contact. The platelet Peclet number at shear rates >100 s-1is large enough (>200) to neglect platelet Brownian motion in computational modeling of flow in arteries and arterioles for most practical purposes even at very close distances from the surface. We also conducted adhesive dynamics simulations to determine the effects of platelet Brownian motion on GPIbα-vWF-A1 single-bond dissociation dynamics. Brownian motion was found to have little effect on bond lifetime and caused minimal bond stressing as bond rupture forces were calculated to be less than 0.005 pN. We conclude from our results that, for the case of platelet-shaped cells, Brownian motion is not expected to play an important role in influencing flow characteristics, platelet−surface contact frequency, and dissociative binding phenomena under flow at physiological shear rates (>50 s-1).