Bioprinting Vascularized Myocardial Patches: Engineering Challenges and Clinical Potential

Background: Myocardial infarction and heart failure result in irreversible loss of cardiomyocytes and microvasculature, leading to impaired contractility and poor regeneration. Bioprinting vascularized myocardial patches offers a promising regenerative strategy by enabling the fabrication of spatially organized, multicellular constructs that recapitulate native cardiac tissue architecture and function. These patches aim to restore myocardial mass, promote revascularization, and integrate electromechanically with host myocardium. However, significant bioengineering and translational challenges remain in achieving clinically viable constructs. Methods and Results: This review explores current strategies, materials, and bioprinting techniques employed in the development of vascularized myocardial patches. Extrusion-based, inkjet, and light-assisted bioprinting methods are used to deposit bioinks composed of cardiomyocytes, endothelial cells, pericytes, and supportive matrix proteins in predefined geometries. Successful vascularization requires co-patterning of vascular channels, angiogenic factor gradients, and perfusable networks to ensure oxygen and nutrient diffusion. Advanced bioinks incorporate decellularized extracellular matrix, conductive polymers, and hydrogels tuned for stiffness and electrical conductivity. Integration with bioreactors and dynamic culture systems promotes tissue maturation and synchronous contraction. Preclinical studies in small and large animal models show improved cardiac function, neovascularization, and graft survival following patch transplantation. Challenges include achieving long-term mechanical stability, immune compatibility, electromechanical integration, and scalable GMP-compliant production. Conclusion: Bioprinting of vascularized myocardial patches represents a cutting-edge convergence of tissue engineering, regenerative cardiology, and advanced manufacturing. With continued refinement in cell sourcing, vascular design, and functional validation, these biofabricated constructs hold substantial potential for clinical translation in myocardial repair and personalized cardiac regeneration.