Building the framework for bioprinted human heart tissue: recent developments and future prospects.

Cardiac bioprinting holds great promise for creating patient-specific grafts and physiologically relevant drug-testing platforms, yet several critical challenges remain. This review identifies key barriers in current cardiac bioprinting approaches, including limitations in bioprinting precision, bioink development, vascularization, functional maturation, and scalable cell sourcing and processing. Recent advances, such as multimodal printing, hybrid bioinks, and perfusable constructs, are discussed with a focus on their application to drug discovery and graft fabrication. We emphasize that targeted maturation may suffice for drug screening, while graft applications demand greater complexity, scale, and immune compatibility. Addressing these challenges through integrated, multidisciplinary strategies will be essential to advance cardiac bioprinting toward clinical and preclinical impact.