Cardiac regeneration revisited: Enhanced cardiomyocyte differentiation and repair through composite microenvironments...

The generation of mature, functional cardiomyocytes from human pluripotent stem cells (hPSCs) remains a major challenge in cardiac regenerative medicine. While fibronectin and Matrigel individually support cardiomyocyte differentiation, their combined potential, particularly when integrated with temporally optimized small-molecule modulation of developmental signaling pathways, has not been systematically investigated.

We engineered a biomimetic fibronectin-Matrigel composite extracellular matrix and applied precisely timed small-molecule modulation of key signaling cascades to drive efficient cardiomyocyte differentiation from hPSCs. Differentiation efficiency, structural organization, and functional maturation were assessed using immunocytochemistry, qRT-PCR, sarcomere imaging, and contractility assays.

This composite microenvironment significantly enhanced cardiac-specific marker expression, promoted highly organized sarcomere architecture, and improved contractile function, producing a maturation profile closely resembling native myocardium. Moreover, the platform supported long-term culture with sustained structural and functional stability and consistently outperformed fibronectin-only or Matrigel-only substrates.

Our study presents a robust, scalable, and mechanistically informed platform that synergistically integrates ECM engineering with targeted signaling pathway modulation. By combining fibronectin-Matrigel composites with small-molecule-directed differentiation, this strategy provides a powerful tool for cardiac tissue engineering, disease modeling, high-throughput drug screening, and regenerative therapies, representing a significant step toward clinically relevant cardiac repair.