Finite element analysis of stem cells mechanical stimulations for differentiation into cardiomyocytes

Heart failure is the leading cause of death in the world and there are still many flaws in its diagnosis. At present, surgical interventions for the treatment of cardiovascular disease are limited to the absence of organ donors for transplantation and the complications of immunosuppressive therapy. Researchers are looking for new ways to regenerate a damaged heart. Tissue engineering has emerged as a new technology using cells with regenerative capacity, scaffolds, and growth factors. Stem cells are optimal cell sources for cardiac tissue engineering due to their ability to self-repair and differentiation into cardiomyocytes. Since the cardiomyocytes inside the body are in a dynamic environment under cyclic strain and pulsatile flow due to the rhythmic heartbeat, these mechanical stimuli are important factors in differentiating stem cells, regulating cardiac tissue function, and homeostasis. This study aims to simulate the effect of pulsatile flow and cyclic strain exerted on a perfusion bioreactor on stem cells for cardiac tissue engineering applications (cardiomyocyte cells). Since shear stress activates transcription pathways, this parameter is very effective in the differentiation of stem cells to cardiomyocytes. The present study attempts to evaluate the effect of frequency on the maximum magnitude of shear stress created on the embryonic stem cell layer. By applying the fluid-solid interaction method to solve the problem by two-way coupling of the equations, the results show that all the obtained values of shear stress at frequencies of 0.33 and 1 Hz and with frequency difference in cyclic strain (0.33 Hz) and pulsatile flow (1 Hz) are in the suitable range for differentiation of the stem cells to cardiomyocytes. The corresponding shear stress values are 0.00562, 0.02 and 0.01 dyn/cm2, respectively.