The feasibility of 3D bioprinting for bone regeneration: key challenges and future directions

Three-dimensional (3D) bioprinting has emerged as a promising biofabrication strategy for bone regeneration, offering unprecedented control over the spatial distribution of cells, biomaterials, and bioactive cues. By enabling the production of anatomically customized grafts with microarchitectural complexity and biological functionality, bioprinting holds potential to overcome limitations associated with autografts, allografts, and synthetic bone substitutes. This review provides a comprehensive synthesis of recent advances in bioprinting technologies, bioink design, and recent <i>in vitro</i> and <i>in vivo</i> studies targeting bone tissue engineering. Despite encouraging preclinical outcomes, the field faces significant challenges, including limited mechanical performance, control over cellular microenvironments, lack of standardization, and trade-offs between printing resolution and scalability. Notably, no clinical trials have yet investigated bioprinted bone constructs, reflecting the translational hurdles that persist. We critically discuss these gaps and propose strategic directions. Collectively, this review underscores the feasibility of 3D bioprinting for bone regeneration while highlighting the key scientific and technical milestones needed to transition from bench to bedside.