Methacrylated human recombinant collagen peptide as a hydrogel for manipulating and monitoring stiffness-related cardiac cell behavior

This study introduces and validates a human recombinant collagen peptide (RCPhC1-MA) hydrogel platform with tunable stiffness for modeling cardiac microenvironments. The authors demonstrate that the hydrogel’s mechanical properties (1–15 kPa) can mimic developing to adult myocardium, supporting the co-culture of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) and cardiac fibroblasts (cFBs) for over 14 days. Real-time monitoring of ECM production and cardiomyocyte contractility revealed that fibroblasts mitigate stiffness-dependent contractile suppression in hPSC-CMs. The system allows controlled decoupling of stiffness and ligand density, offering a human-relevant, reproducible alternative to animal-derived hydrogels for cardiac tissue modeling and drug testing.