Digital light processing bioprinting: bioink innovations and applications in tissue and organ regeneration

Digital light processing (DLP) bioprinting offers superior spatial resolution, rapid printing speed, and gentle cell handling compared to extrusion- and inkjet-based methods. By enabling layer-by-layer photopolymerization through projected light patterns, DLP provides precise control over microscale architecture, making it highly suitable for fabricating tissue- and organ-specific constructs. However, the true potential of DLP bioprinting depends not only on optical precision but also on the development of photocurable bioinks that translate light-driven fabrication into biologically relevant outcomes. Recent advances in bioink development (including methacrylated natural polymers, decellularized extracellular matrix (dECM)-derived hydrogels, hybrid nanocomposites, and cell-laden formulations) have significantly expanded the biofabrication landscape. These materials enable the creation of constructs that closely mimic native tissues such as corneas, cartilage, liver, and skeletal muscle in terms of structural and biochemical complexity. Furthermore, strategies such as photoabsorber modulation, rheological tuning, and dual crosslinking mechanisms have improved print fidelity and cytocompatibility. Despite this progress, translational barriers remain. Limited vascularization, poor scalability, and insufficient functional longevity continue to restrict clinical adoption. This review critically examines how bioink design paradigms in DLP bioprinting redefine the interface between light-based engineering and biological function. We also discuss emerging trends in stimuli-responsive and cell-instructive bioinks, offering insights into how to bridge laboratory innovation with clinically relevant tissue regeneration.