Endothelial, cardiac muscle and skeletal muscle exhibit different viscous and elastic properties as determined by atomic force microscopy
Endothelial, cardiac muscle and skeletal muscle exhibit different viscous and elastic properties as determined by atomic force microscopy
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DOI：
10.1016/s0021-9290(01)00149-x
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发表时间：
2001-12-01
影响因子：
2.4
通讯作者：
Truskey, GA
中科院分区：
文献类型：
--
作者：
Mathur, AB;Collinsworth, AM;Truskey, GA
本研究对以下假设进行了评估：由于功能和结构的差异，心肌、骨骼肌以及血管内皮的表观弹性模量和粘性行为会有所不同。为了准确测定弹性模量，对探针速度、压痕深度以及假定的探针形状的影响进行了研究。在高压痕速度下，由于粘性效应观察到了滞后现象。对于内皮细胞未观察到不可逆变形，并且在低于1μm/s的速度下滞后现象可忽略不计。对于骨骼肌和心肌细胞，在低于0.25μm/s的速度下滞后现象可忽略不计。内皮细胞和心肌细胞的粘性耗散高于骨骼肌细胞。对于这三种细胞类型，在压痕的前60nm范围内，计算所得的弹性模量对假定的探针几何形状最为敏感。将探针模拟为钝圆锥 - 球形帽时，弹性模量随压痕深度的变化小于将探针视为圆锥尖端时所计算出的变化。由于在压痕深度大于60nm时弹性模量达到稳定值，并且探针的压痕深度从未超过细胞厚度的10%，所以基底的影响可忽略不计。心肌细胞最硬（100.3±10.7kPa），骨骼肌细胞居中（24.7±3.5kPa），内皮细胞最软，其弹性模量范围（1.4±0.1至6.8±0.4kPa）取决于所测试的细胞表面位置。心肌和骨骼肌表现出非线性弹性行为。这些被动力学性能通常与这些不同细胞类型的功能相符。（C）2001 Elsevier Science Ltd.保留所有权利。
This study evaluated the hypothesis that, due to functional and structural differences, the apparent elastic modulus and viscous behavior of cardiac and skeletal muscle and vascular endothelium would differ. To accurately determine the elastic modulus, the contribution of probe velocity, indentation depth., and the assumed shape of the probe were examined. Hysteresis was observed at high indentation velocities arising from viscous effects. Irreversible deformation was not observed for endothelial cells and hysteresis was negligible below 1 mum/s. For skeletal muscle and cardiac muscle cells, hysteresis was negligible below 0.25 mum/s. Viscous dissipation for endothelial and cardiac muscle cells was higher than for skeletal muscle cells. The calculated elastic modulus was most sensitive to the assumed probe geometry for the first 60 nm of indentation for the three cell types, Modeling the probe as a blunt cone-spherical cap resulted in variation in elastic modulus with indentation depth that was less than that calculated by treating the probe as a conical tip. Substrate contributions were negligible since the elastic modulus reached a steady value for indentations above 60 nm and the probe never indented more than 10% of the cell thickness. Cardiac cells were the stiffest (100.3 +/- 10.7 kPa), the skeletal muscle cells were intermediate (24.7 +/- 3.5 kPa), and the endothelial cells were the softest with a range of elastic moduli (1.4 +/- 0.1 to 6.8 +/- 0.4 kPa) depending on the location of the cell surface tested. Cardiac and skeletal muscle exhibited nonlinear elastic behavior. These passive mechanical properties are generally consistent with the function of these different cell types. (C) 2001 Elsevier Science Ltd. All rights reserved.