Physiological Calcium Combined with Electrical Pacing accelerates Maturation of Human Engineered Heart Tissue

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have wide potential application in basic research, drug discovery, and regenerative medicine, but functional maturation remains challenging. Here, we present a simple method whereby maturation of hiPSC-CMs can be accelerated by simultaneous application of physiological Ca 2+ and frequency-ramped electrical pacing in culture. This combination produces realistic force-frequency relationship, physiological twitch kinetics, robust ß-adrenergic response, improved Ca 2+ handling, and cardiac troponin I expression within 25 days. This study provides insights into the role of Ca 2+ in hiPSC-CM maturation and offers a scalable platform for translational and clinical research. Overall design: Gene expression profile analysis of 4 experimental groups of engineered heart tissues (EHTs). The four groups are: High Calcium Ramp Pacing (HCRP), High Calcium No Pacing (HCNP), Low Calcium Ramp Pacing (LCRP) and Low Calcium No Pacing (LCNP)