Cardiomyocyte Growth on Cardiac Infusible Extracellular Matrix-Coated and Annealed Biodegradable Polyurethane Fibers

Biodegradable polyurethane (PU) is a promising biomaterial for tissue repair due to its customizable mechanical properties, high elasticity, biocompatibility, and biodegradability. Electrospun PU fibers are valued for their structural similarity to extracellular matrices but undergo shrinkage under physiological conditions, resulting in morphological changes. This study investigated strategies to mitigate shrinkage and enhance the functionality of PU fibers for the cardiac cell culture. Aligned PU fibers were annealed at varying temperatures (50 and 100 °C) to reduce shrinkage, and then 100 °C-annealed fibers were coated with pig heart-derived infusible extracellular matrix (iECM) to promote H9c2 cell adhesion and growth. Annealing at 100 °C significantly reduced shrinkage of the PU fibers compared to non-annealed and 50 °C-annealed fibers. Thermal annealing led to smaller fiber diameters. The iECM coating increased the surface hydrophilicity and improved H9c2 proliferation. Upregulation of cardiac markers, including <i>Cx43</i>, <i>TNNT2</i>, and <i>MYL2</i>, indicated enhanced cardiac differentiation on iECM-coated fibers compared to uncoated fibers. These findings suggest that 100 °C-annealed PU fibers with iECM coating can offer improved morphology stability, mechanical performance, and biofunction, making them suitable for cardiac cell culture and tissue repair.