[Diffusion model for the dynamics of fibroblast initial attachment]

The simplest model for the formation of initial cell--substrate contact from the discrete multitude of the contacts of small cell surface projections named spheropodia (SP) is presented. The main points of the model are: 1) the multitude of SP is homogenous; 2) there are at least two states of SP, S0--free SP, S1--attached SP; 3) transitions between the states are stochastic and independent. There were two criteria for the selection of concrete models. Firstly it must assume the great number of microcontacts. Secondly the parameters of the model function v(t, x) must coincide with the parameters of experimental function v(t, x). The model function is the probability that at the moment t the cell has the attachment force not smaller than the threshold value x. It is shown that the diffusion model satisfied these criteria. In this model the stochastic process of cell attachment is described as a diffusion process with positive drift in the one-dimensional space of the summing cell attachment force.