3D bioprinting of cell-laden constructs: technologies, bioink design, and biomedical applications

Three-dimensional (3D) cell printing is rapidly redefining how we engineer tissues by enabling the precise delivery of living cells within bio-inks to build complex, cell-laden structures. Unlike traditional approaches that seed cells onto inert scaffolds, this technique allows direct integration of cells into the construct, promoting enhanced cell infiltration, extracellular matrix (ECM) remodeling, and tissue-like functionality. Despite the explosion of interest, the field remains fragmented, with limited efforts to unify emerging data across platforms and applications. Our review addresses this gap by synthesizing recent advances in 3D cell printing in terms of key printing factors and parameters and adaptive bioprinting, presenting consensus and translative information such as printing parameters, identifying current established applications, and proposing future research directions based on the current<i>in vivo</i>or clinical results. We map current trends across biomaterial choices-including gelatin, decellularized ECM, alginate, collagen I, and fibrin-and explore how diverse cell types, from primary human cells to engineered stem cell derivatives, are shaping the future of tissue fabrication. These innovations are already influencing<i>in vivo</i>research in skin regeneration, cartilage repair, and vascular grafts, while the high-resolution capabilities of 3D printing are powering next-generation organ-on-chip models. We conclude with key translational challenges and propose future research priorities to move from bench to bedside.