Freyman T M, Yannas I V, Yokoo R, Gibson L J
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
Exp Cell Res. 2002 Jan 15;272(2):153-62. doi: 10.1006/excr.2001.5408.
Using a device named the cell force monitor, the contractile force developed by fibroblasts has been studied by measuring the macroscopic contraction of porous collagen-glycosaminoglycan (GAG) matrices over the first 24 h following cell attachment. In this paper, the effect of a variation in the stiffness that resists matrix contraction by cells on the contractile force generated by the cells was determined. Data from these experiments revealed that the contractile force generated by the fibroblasts was independent of the stiffness of the resistance within the range tested (0.7-10.7 N/m). These results suggest that during the time when fibroblasts are attaching to and spreading on collagen-GAG matrices the contractile forces they generate are force limited, not displacement limited. Therefore, the cytoskeletal mechanism of force generation, corresponding with cell elongation, is capable of increasing the displacement of adhesion sites in order to develop the same level of force. Although a detailed understanding of how the passive mechanical signals provided by substrate materials affect cell processes is still unavailable, in vitro modeling of cell-mediated contraction continues to provide useful information.
使用一种名为细胞力监测仪的设备，通过测量细胞附着后头24小时内多孔胶原 - 糖胺聚糖（GAG）基质的宏观收缩，研究了成纤维细胞产生的收缩力。在本文中，确定了细胞抵抗基质收缩的刚度变化对细胞产生的收缩力的影响。这些实验的数据表明，在所测试的范围内（0.7 - 10.7 N/m），成纤维细胞产生的收缩力与阻力的刚度无关。这些结果表明，在成纤维细胞附着于胶原 - GAG基质并在其上铺展的时间段内，它们产生的收缩力是力限制型的，而非位移限制型的。因此，与细胞伸长相对应的产生力的细胞骨架机制能够增加黏附位点的位移，以产生相同水平的力。尽管对底物材料提供的被动机械信号如何影响细胞过程仍缺乏详细了解，但细胞介导收缩的体外模型仍在持续提供有用信息。
