RESUMO
@#Objective To investigate whether recombinant human serum albumin (rHSA) can replace traditional B27 as a basic medium for differentiation of human pluripotent stem cells (hPSCs) into cardiomyocytes. Methods hPSCs were seeded at a cell density of 1.2×104/cm2; until up to 75% confluency hPSCs were induced by differentiation medium containing various concentration of rHSA (0, 50, 100, 200 g/L). Light microscope and fluorescence microscope recorded the whole process of stem cells differentiating into myocardium. Flow cytometry was used to detect the cardiac differentiation efficiency at different concentrations of rHSA. Immunofluorescence staining was used to detect the cardiac specific protein α-actinin and troponin T (cTnT) and electron microscope to observe the ultrastructure of human pluripotent stem cell-derived cardiomyocytes (hPSC-CM) and beating rates of hPSC-CMs response to drugs. Results A large number of spontaneous beating cardiomyocytes were observed 9 days after induction and differentition. The percentage of colonies showing beating cardiomyocytes was 60.4% at the concentration of 200 g/L of rice derived-rHSA. Beating cardiomyocytes were α-actinin and cTnT positive. Ultrastructural analysis showed scattered sarcomeres and mitochondrial. hPSC-CMs were dose-dependent on isopropyl adrenaline and verapamil. Conclusion Using such simple media to differentiate hPSCs into functional cardiomyocytes is cost-effective and highly efficient, and can be used in the clinical research.