Dynamic fatigue measurement of human erythrocytes using dielectrophoresis
Dynamic fatigue measurement of human erythrocytes using dielectrophoresis
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DOI：
10.1016/j.actbio.2017.05.037
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发表时间：
2017-07-15
影响因子：
9.7
通讯作者：
Du, E.
中科院分区：
文献类型：
--
作者：
Qiang, Yuhao;Liu, Jia;Du, E.
红细胞在正常寿命内必须经历严重的变形，才能通过狭窄的毛细血管和亚微米的脾缝隙数十万次。对红细胞生物力学的研究主要集中在单个应力作用下的细胞变形性和流变学，主要是利用经典的生物力学技术，如光镊法和微吸管吸引法，测量细胞在静态或准静态下的变形和流变学。红细胞在周期性应力作用下的动态行为还不完全清楚，而周期性压力是导致血液循环中细胞膜失效的原因。本文提出了一种利用微流控平台上的调幅电动力场进行红细胞动态疲劳分析的新实验方法。我们通过对正常人红细胞和耗尽三磷酸腺苷的红细胞进行低周疲劳分析，证明了这种新技术的能力。产生循环拉伸应力，以诱导单个红细胞的重复单轴拉伸和拉伸恢复。单独跟踪的红细胞的形态和生物力学参数的结果表明，与加载循环的次数有很强的相关性。在相同电场强度下，180次应力循环后，正常红细胞的最大拉伸比从3.8降至2.86，细胞伸长恢复的特征时间从0.16 S增加到0.37 S，膜剪切粘度从1.0mU N/m S增加到1.6mN/m S，少数红细胞膜变形在200周左右的大变形后不可逆。随着加载周期的延长，耗尽ATP的细胞在变形减少和特征时间增加方面表现出相似的趋势。这些结果证明了用于人体红细胞动态疲劳分析的新的微流体技术的概念。有意义的陈述红细胞(RBC)在失去机械变形能力并最终在网状内皮系统中降解之前，在血液循环中经历了大量的变形。以往的红细胞生物力学研究主要集中在单次施加应力，或通过物理接触使细胞膜变形的准静态载荷，因此在探测细胞对循环应力的动态响应方面的能力有限。我们提出了一种独特的电动微流控系统，用于研究循环载荷下红细胞的动态疲劳行为。我们的工作定量地展示了循环拉伸载荷是如何导致膜机械降解和细胞不可逆变形的。这项新技术可用于识别生物力学标志物，以预测循环红细胞的机械稳定性和剩余寿命。(C)2017 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
Erythrocytes must undergo severe deformation to pass through narrow capillaries and submicronic splenic slits for several hundred thousand times in their normal lifespan. Studies of erythrocyte biomechanics have been mainly focused on cell deformability and rheology measured from a single application of stress and mostly under a static or quasi-static state using classical biomechanical techniques, such as optical tweezers and micropipette aspiration. Dynamic behavior of erythrocytes in response to cyclic stresses that contributes to the membrane failure in blood circulation is not fully understood. This paper presents a new experimental method for dynamic fatigue analysis of erythrocytes, using amplitude modulated electrokinetic force field in a microfluidic platform. We demonstrate the capability of this new technique using a low cycle fatigue analysis of normal human erythrocytes and ATP-depleted erythrocytes. Cyclic tensile stresses are generated to induce repeated uniaxial stretching and extensional recovery of single erythrocytes. Results of morphological and biomechanical parameters of individually tracked erythrocytes show strong correlations with the number of the loading cycles. Under a same strength of electric field, after 180 stress cycles, for normal erythrocytes, maximum stretch ratio decreases from 3.80 to 2.86, characteristic time of cellular extensional recovery increases from 0.16 s to 0.37 s, membrane shear viscosity increases from 1.0 (mu N/m) s to 1.6 (mu N/m) s. Membrane deformation in a small number of erythrocytes becomes irreversible after large deformation for about 200 cyclic loads. ATP-depleted cells show similar trends in decreased deformation and increased characteristic time with the loading cycles. These results show proof of concept of the new microfluidics technique for dynamic fatigue analysis of human erythrocytes.Statement of significanceRed blood cells (RBCs) experience a tremendous number of deformation in blood circulation before losing their mechanical deformability and eventually being degraded in the reticuloendothelial system. Prior efforts in RBC biomechanics have mostly focused on a single-application of stress, or quasi-static loading through physical contact to deform cell membranes, thus with limited capabilities in probing cellular dynamic responses to cyclic stresses. We present a unique electrokinetic microfluidic system for the study of dynamic fatigue behavior of RBCs subjected to cyclic loads. Our work shows quantitatively how the cyclic stretching loads cause membrane mechanical degradation and irreversibly deformed cells. This new technique can be useful to identify biomechanical markers for prediction of the mechanical stability and residual lifespan of circulating RBCs. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.