Efficient differentiation of human pluripotent stem cells into cardiomyocytes on cell sorting thermoresponsive surface

The current differentiation process of human pluripotent stem cells (hPSCs) into cardiomyocytes to enhance the purity of hPSC-derived cardiomyocytes requires some purification processes, which are laborious processes. Here, the authors have developed cell sorting plates, which are prepared from coating thermoresponsive poly(N-isopropylacrylamide) and extracellular matrix proteins vitronectin or Biolaminin 521. The Biolaminin 521-coated surface exhibited higher beating colony numbers than the vitronectin-coated surface. This is explained by the fact that hPSC-derived cardiomyocytes express less integrin αVβ5 but more α6β1, where the main binding sites of rVN and LN-521 are integrin αVβ5 and integrin α6β1, respectively. After hPSCs were induced into cardiomyocytes on the thermoresponsive surface coated with Biolaminin 521 for 15 days, the cells were detached partially from the thermoresponsive surface. The detached cells exhibited a higher cardiomyocyte marker of cTnT than the remaining cells on the thermoresponsive surface as well as the cardiomyocytes after purification using conventional cell selection. The detached cells expressed several cardiomyocyte markers, such as α-actinin, MLC2a, and NKX2.5. This study a promising method for the purification of hPSC-derived cardiomyocytes without conventional laborious processes.