Volumetric 3D Printing and Melt-Electrowriting to Fabricate Implantable Reinforced Cardiac Tissue Patches

This work introduces a reinforced cardiac tissue patch (RCPatch) engineered for intraventricular myocardial repair—an application where current biological and synthetic cardiac patches fail due to insufficient strength, permeability, or integration. The authors combined volumetric 3D-printed poly(ε-caprolactone) (PCL) metamaterials with a melt-electrowritten (MEW) mesh infiltrated by a cardiomyocyte-laden fibrin hydrogel. A graph-based generative modeling and finite-element workflow produced metamaterials with myocardium-matched anisotropic stiffness, enabling robust structural reinforcement while supporting cell infiltration and contractility. The integrated MEW mesh reduced permeability and provided suture retention for surgical handling. In a porcine acute implantation model involving an 8 mm transmural ventricular defect, the RCPatch withstood ≈80 mmHg intraventricular pressure, prevented bleeding, and supported partial hemodynamic recovery. These findings demonstrate a scalable approach for fabricating implantable, mechanically tuned, and biologically functional cardiac patches suitable for high-pressure intraventricular environments.