• Specific RA concentration (0.1 μM) during days 3-6 of hiPSC differentiation yields left ventricle-like cardiomyocytes with enhanced contractile protein expression and functional properties.
• Engineered heart tissues from HRA-treated cells exhibit higher contraction force, lower beating frequency, and increased sensitivity to hypoxia and isoprenaline, closely mimicking left ventricular physiology.
• RNA sequencing reveals that RA promotes augmented extracellular matrix strength, which underlies the heightened contractility of EHTs.
• This study provides a novel method to generate ventricle-specific cardiomyocytes and EHTs, advancing personalized drug screening and regenerative medicine.