A computational simulation of cyclic stretch of an individual stem cell using a nonlinear model.

Many experiments have shown that mechanical stimuli like cyclic strains might be helpful in stem cell differentiation. To maximize such differentiations efficiency, it is imperative to detect the cellular mechanical responses to these stimuli. The purpose of this research was to show that a newly presented hyper-viscoelastic model could correctly predict the level of stresses required to obtain a different response from a single mesenchymal stem cell cultured in a fibrin hydrogel block under a 10% cyclic strain at a frequency of 1 Hz, employing finite element method. One of the novelties of the research was the use of a model based on Simo's model. Another important feature of the research was the proposition of a multiscale model considering a layer of integrins. It was concluded that the forces exerted on the biological molecules had the maximum values of 24, 45, and 15 pN for the circumferential, radial, and shear forces, respectively. According to the results, the exerted forces within the cytoskeleton can lead to a different cellular response. These results might be a premise for interpreting events that lead to differentiation of stem cells into fibrochondrocytes. In addition, they can be beneficial in effective design of biological experiments as regards to this issue.