Assessment of the mechanical properties of the nucleus inside a spherical endothelial cell based on microtensile testing
Assessment of the mechanical properties of the nucleus inside a spherical endothelial cell based on microtensile testing
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DOI：
10.2140/jomms.2007.2.1087
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发表时间：
2007-06-01
影响因子：
0.9
通讯作者：
Tsujioka, Katsuhiko
中科院分区：
文献类型：
--
作者：
Deguchi, Shinji;Yano, Masayuki;Tsujioka, Katsuhiko
细胞外力对细胞核变形的影响是更好地理解细胞内力传递机制的重要研究问题。采用单细胞的微拉伸试验来解决这个问题是有帮助的，因为该试验使人们能够在宽的力和应变范围内对试样施加良好控制的载荷。在本研究中，具有球形的单细胞的拉伸试验进行通过使用微拉伸试验系统与位移速率的反馈控制。然后基于图像分析来量化在单元拉伸期间单元内的核的变形和随后的卸载后的蠕变恢复。为了表征细胞及其核的蠕变恢复行为，一维解析粘弹性模型和幂律函数拟合的蠕变恢复数据。此外，进行系统的有限元分析，以估计细胞内的应力分布和弹性模量的细胞和核假设为连续体材料。这些结果表明，在拉伸和卸载下的细胞内的核的力学行为是类似的压缩载荷下以前报道的。
The effect of extracellular forces on the nucleus deformation is an important research issue for better understanding of the intracellular force transmission mechanism. Approaches to this issue employing a microtensile test of single cells are helpful because the test enables one to give a well-controlled load onto the specimen with wide force and strain ranges. In the present study, tensile tests of single cells having a spherical shape are conducted by using a microtensile test system with a feedback control of displacement rate. Deformations of the nucleus inside the cell during the cell stretch and subsequent creep recovery after unloading are then quantified based on an image analysis. In order to characterize the creep recovery behaviors of the cell and its nucleus, one-dimensional analytical viscoelastic models and a power-law function are fitted to the creep recovery data. In addition, systematic finite element analyses are performed to estimate the intracellular stress distribution and elastic modulus of the cell and nucleus assumed to be continuum materials. These results indicate that the mechanical behaviors of the nucleus within a cell under stretching and unloading are similar to those under compression loadings previously reported.