GelMA hydrogels for bone regeneration: Linking clinical scenarios with biofabrication

Objectives Critical-sized bone defects in cranio-maxillofacial, orthopedic, and dental settings remain difficult to treat because conventional grafts and synthetic substitutes rarely provide simultaneous space maintenance, mechanical stability, and long-term integration. Gelatin methacryloyl (GelMA) has emerged as a promising hydrogel platform, combining extracellular matrix (ECM)-derived bioactivity with photocrosslinkable chemistry, tunable mechanics, and compatibility with advanced biofabrication. However, most studies still emphasize material synthesis and generic applications rather than configuration for specific clinical environments. This review therefore reframes GelMA-based bone regeneration around the clinical setting in which the scaffold must function. Methods This is a narrative, scenario-driven synthesis rather than a systematic review. PubMed, Web of Science, and Scopus were searched for GelMA-based bone studies, mainly from 2015 onward, and representative work was prioritized when it reported a defined fabrication route and defect-relevant structural, biological, or in vivo outcomes. Results Recent GelMA-based strategies are organized into four clinical scenarios: (i) large or irregular defects needing robust space maintenance and perfusable architectures; (ii) periodontal and maxillofacial defects requiring durable, selectively permeable guided bone regeneration membranes; (iii) post-surgical or open defects with high infection risk that demand sustained local antibacterial and immunomodulatory activity; and (iv) ischemic or irradiated defects, in which pro-angiogenic, antioxidant, and immune-reprogramming functions are essential. We map acellular 3D printing, cell-laden bioprinting, electrospinning, GelMA microgels, and hybrid combinations to scenario-specific design requirements across these clinical settings. We also outline key translational priorities—standardized GelMA synthesis, controlled photocuring, and safety-verified multifunctional composites—to support defect- and scenario-specific bone regeneration. Conclusions By linking clinical need, fabrication strategy, and biological function, this review positions GelMA as a flexible platform for defect- and scenario-specific bone regeneration. Because the synthesis is narrative, the comparative tables are qualitative and not head-to-head benchmarking.