A finite element model of cell deformation during magnetic bead twisting
A finite element model of cell deformation during magnetic bead twisting
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DOI：
10.1152/japplphysiol.00255.2002
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发表时间：
2002-10-01
影响因子：
3.3
通讯作者：
Fredberg, JJ
中科院分区：
文献类型：
--
作者：
Mijailovich, SM;Kojic, M;Fredberg, JJ
磁扭转细胞仪通过向紧密结合到细胞表面的磁珠施加扭矩来探测粘附细胞的机械特性。在这里，我们已经使用了一个三维有限元模型的细胞变形计算之间的关系所施加的扭矩和所产生的珠旋转和横向珠平移。从分析中，我们计算了两个系数，允许从测量珠旋转或横向珠平移，分别估计细胞弹性模量，如果珠嵌入的程度和细胞高度是已知的。尽管计算的靠近胎圈的应变可能很大，但施加的扭矩与胎圈旋转或平移之间的关系在胎圈旋转15度时几乎保持线性，超过15度时，几何非线性变得显著。这种明显的线性范围与原子力显微镜观察细胞时观察到的内在非线性力-位移关系相反。最后，这些计算支持的想法，粘附力是足够的，以保持牢固地连接到整个工作扭矩范围内的细胞表面的珠。
Magnetic twisting cytometry probes mechanical properties of an adherent cell by applying a torque to a magnetic bead that is tightly bound to the cell surface. Here we have used a three-dimensional finite element model of cell deformation to compute the relationships between the applied torque and resulting bead rotation and lateral bead translation. From the analysis, we computed two coefficients that allow the cell elastic modulus to be estimated from measurements of either bead rotation or lateral bead translation, respectively, if the degree of bead embedding and the cell height are known. Although computed strains in proximity of the bead can be large, the relationships between applied torque and bead rotation or translation remain virtually linear up to bead rotations of 15degrees, above which geometrical nonlinearities become significant. This appreciable linear range stands in contrast to the intrinsically nonlinear force-displacement relationship that is observed when cells are indented during atomic force microscopy. Finally, these computations support the idea that adhesive forces are sufficient to keep the bead firmly attached to the cell surface throughout the range of working torques.