Lee K, Priezzhev A, Shin S, Yaya F, Meglinski I
Optoelectronics and Measurement Techniques, University of Oulu, Oulu, Finland.
Department of Physics, M. V. Lomonosov Moscow State University, Moscow, Russia.
Clin Hemorheol Microcirc. 2016;64(4):853-857. doi: 10.3233/CH-168020.
The novel measure of the red blood cells (RBC) aggregation (RBC-A) - the critical (minimum) shear stress (CSS) to prevent the cells from aggregation was found to be a promising clinically significant parameter. However, the absolute values of this parameter were found to change significantly depending on the shearing geometry (cup-and-bob, cone-plate or microchannel-flow) and have different temperature dependences along with it. The direct confirmation of these dependences aimed to find out the correct values is still pending.
In this work, we aim to assess the absolute values of CSS at different temperatures.
The single cell level measurements of CSS were performed using optical tweezers. The measurements were carried out in heavily diluted suspensions of RBCs in plasma.
The temperature dependent changes in CSS were measured at the points (22 and 38°C), in which the cup-and-bob and cone-plate systems yielded about 1.5-fold different values, while the microchannel-flow system yielded a constant value. The single cell CSS were found to be 362±157 mPa (22°C) and 312±57 mPa (38°C).
Our results prove that the microfluidic-flow approach is reflecting the RBC-A correctly. While the CSS values measured with other systems show the temperature dependent effect of the shearing geometry.
红细胞聚集（RBC-A）的新测量指标——防止细胞聚集的临界（最小）剪切应力（CSS）被发现是一个有前景的具有临床意义的参数。然而，该参数的绝对值会因剪切几何形状（杯-锥、锥板或微通道流）而发生显著变化，并且与之伴随的还有不同的温度依赖性。关于这些依赖性的直接确认，以找出正确值的工作仍在进行中。
在这项工作中，我们旨在评估不同温度下CSS的绝对值。
使用光镊对CSS进行单细胞水平测量。测量在血浆中高度稀释的红细胞悬液中进行。
在（22和38°C）这两个点测量了CSS随温度的变化，其中杯-锥和锥板系统产生的值相差约1.5倍，而微通道流系统产生的是恒定值。单细胞CSS在22°C时为362±157 mPa，在38°C时为312±57 mPa。
我们的结果证明微流控流动方法能正确反映RBC-A。而用其他系统测量的CSS值显示出剪切几何形状的温度依赖性效应。
