3D Bioprinting Functional Engineered Heart Tissues

Three-dimensional (3D) bioprinting is increasingly explored as a strategy for myocardial repair and regenerative medicine. Conventional 3D casting often yields heterogeneous cellularization, slow electromechanical maturation, and inadequate vascularization; by contrast, bioprinting places cells and biomaterials in predefined architectures to program alignment, stiffness, vascular pathways, and electrical coupling that better recapitulate native myocardium. This review focuses on cardiac-specific advances in 3D bioprinting. We compare major platforms (jetting, light-based, extrusion, and volumetric) and their trade-offs for cardiac applications; distill bioink design principles trending toward natural-synthetic hybrids, including conductive and shape-morphing components; and outline practical characterization readouts spanning rheology, print fidelity, swelling/degradation, and cardiac function. We also summarize cell sources and co-culture strategies. Applications surveyed include cardiac patches, engineered tissues, chambered constructs, and organoids. Finally, we discuss current limitations and potential future directions for 3D bioprinting cardiac tissues. Collectively, recent advances position 3D bioprinting to accelerate the realization of in vivo-like engineered heart tissues.