3D BIOPRINTING OF HUMAN ORGANS: CURRENT PROGRESS AND FUTURE PROSPECTS

Abstract

Three-dimensional (3D) bioprinting merges additive manufacturing with cell biology to fabricate living tissues with spatially controlled architectures. Over the past decade, extrusion, droplet-based, and light-based bioprinting modalities have advanced from proof-of-concept constructs to clinically oriented, prevascularized tissues. Concomitantly, bioink chemistry—spanning gelatin methacryloyl (GelMA), decellularized extracellular matrix (dECM), collagen/fibrin, alginate, and synthetic PEG derivatives—has matured to support print fidelity, cell viability, and functional maturation. Yet translation to whole-organ replacement remains constrained by inadequate multiscale vascularization and lymphatic drainage, limited innervation, immune compatibility, manufacturing metrology, and regulatory pathways. Here we synthesize the state of the art in tissue prototypes (skin, cartilage, bone, liver, cardiac, renal), highlight enabling technologies (sacrificial/vessel printing, embedded/FRESH printing, perfusion bioreactors, digital twins), and outline a roadmap for quality-by-design (QbD) manufacturing and clinical evaluation. We conclude with near-term prospects for skin and osteochondral grafts, mid-term goals for hepatic/kidney functional units, and long-term strategies toward architected organ systems.