Departamento de Física, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil.
Central Analítica, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil.
Sci Rep. 2020 Mar 16;10(1):4749. doi: 10.1038/s41598-020-61631-w.
Living cells are constantly exchanging momentum with their surroundings. So far, there is no consensus regarding how cells respond to such external stimuli, although it reveals much about their internal structures, motility as well as the emergence of disorders. Here, we report that twelve cell lines, ranging from healthy fibroblasts to cancer cells, hold a ubiquitous double power-law viscoelastic relaxation compatible with the fractional Kelvin-Voigt viscoelastic model. Atomic Force Microscopy measurements in time domain were employed to determine the mechanical parameters, namely, the fast and slow relaxation exponents, the crossover timescale between power law regimes, and the cell stiffness. These cell-dependent quantities show strong correlation with their collective migration and invasiveness properties. Beyond that, the crossover timescale sets the fastest timescale for cells to perform their biological functions.
活细胞不断与其周围环境交换动量。到目前为止，对于细胞如何对外界刺激做出反应，虽然它揭示了它们的内部结构、运动以及疾病的发生机制，但还没有达成共识。在这里，我们报告说，从健康成纤维细胞到癌细胞的 12 种细胞系具有普遍存在的双幂律粘弹性弛豫，与分数 Kelvin-Voigt 粘弹性模型兼容。我们采用时域原子力显微镜测量来确定力学参数，即快和慢松弛指数、幂律区之间的交叉时间尺度以及细胞硬度。这些与细胞相关的量与它们的集体迁移和侵袭特性密切相关。除此之外，交叉时间尺度为细胞执行其生物学功能设定了最快的时间尺度。
