Bottino D C, Fauci L J
Department of Mathematics, University of Utah, Salt Lake City 84112, USA.
Eur Biophys J. 1998;27(5):532-9. doi: 10.1007/s002490050163.
Traditional continuum models of ameboid deformation and locomotion are limited by the computational difficulties intrinsic in free boundary conditions. A new model using the immersed boundary method overcomes these difficulties by representing the cell as a force field immersed in fluid domain. The forces can be derived from a direct mechanical interpretation of such cell components as the cell membrane, the actin cortex, and the transmembrane adhesions between the cytoskeleton and the substratum. The numerical cytoskeleton, modeled as a dynamic network of immersed springs, is able to qualitatively model the passive mechanical behavior of a shear-thinning viscoelastic fluid (Bottino 1997). The same network is used to generate active protrusive and contractile forces. When coordinated with the attachment-detachment cycle of the cell's adhesions to the substratum, these forces produce directed locomotion of the model ameba. With this model it is possible to study the effects of altering the numerical parameters upon the motility of the model cell in a manner suggestive of genetic deletion experiments. In the context of this ameboid cell model and its numerical implementation, simulations involving multicellular interaction, detailed internal signaling, and complex substrate geometries are tractable.
传统的阿米巴样变形和运动连续体模型受到自由边界条件固有计算困难的限制。一种使用浸入边界方法的新模型通过将细胞表示为浸入流体域的力场来克服这些困难。这些力可以从对细胞膜、肌动蛋白皮层以及细胞骨架与基质之间的跨膜粘附等细胞成分的直接力学解释中推导出来。数值细胞骨架被建模为浸入式弹簧的动态网络，能够定性地模拟剪切变稀粘弹性流体的被动力学行为（博蒂诺，1997年）。同一网络用于产生主动突出力和收缩力。当与细胞与基质的粘附-脱离循环协调时，这些力会使模型变形虫产生定向运动。使用该模型，可以以类似于基因缺失实验的方式研究改变数值参数对模型细胞运动性的影响。在这种变形虫样细胞模型及其数值实现的背景下，涉及多细胞相互作用、详细内部信号传导和复杂底物几何形状的模拟是可行的。
