Directed Cardiomyocyte Differentiation from hiPSCs

Cardiomyocyte differentiation was performed in CardioEasy medium (Cellapy China) by temporal modulation of the canonical WNT signaling pathway with GSK3 inhibitor and WNT inhibitor, as described in previous protocol [2 (link)]. CardioEasy medium, consisting of RPMI 1640 medium, 500 µg/ml O. sativa-derived recombinant human albumin (Sigma-Aldrich), and 213 µg/ml l-ascorbic acid 2-phosphate (Sigma-Aldrich), is abbreviated as CDM3 medium. Briefly, at day 0, 80–90% confluent hiPSCs were cultured in CDM3 medium with 6 µM CHIR99021 (SML1046, Sigma, USA) for 48 h. At day 2, medium was changed to CDM3 medium supplemented with 2 µM WNT-C59 (S7037, Selleck Chemicals) and continued to incubate for 48 h. Medium was refreshed on day 4 and every other day for CDM3 medium. The contracting cardiomyocytes can be noted from day 7.