Study on the Influence of Shear Stress and Pulse Electrical Stimulation to the Growth of Cardiomyocytes

Engineered myocardial tissue is expected to be used in the treatment of myocardial defects and other diseases, and one of the keys is to construct a suitable environment for the culture of myocardial tissue in vitro. In this study, flow shear stress and pulse electrical stimulation were applied to cardiomyocytes with a self-designed device by simulating the mechanical and electrical physiological microenvironment of myocardial tissue. The strength and duration of pulse electrical stimulation as well as the intensity of shear stress were studied in detail to optimize the experimental parameters. Concretely, 100 mV pulse electrical stimulation (1 Hz and 10 ms pulse width) and 10 dyn/cm² shear stress were used for studying the influence of combined mechanical-electrical stimulation to the growth of cardiomyocytes. The mechanical factor of the combined stimulation promoted the expression of α-cardiac actin mRNA, the electrical factor caused an increase in Cx-43 mRNA expression, and shear stress and pulse electrical stimulation showed a synergistic action on the expression of GATA-4 mRNA. It indicated that combined mechanical-electrical stimulation had a better effect on the functionalized culture of cardiomyocytes, which provided an important theoretical basis for the further construction of in vitro engineered myocardial tissue.