Bone regeneration using aged donor cells and visible light‐curable hydrogel: An in vitro and in vivo evaluation

Regenerative medicine combining scaffold materials and cell transplantation shows promise for widespread bone regeneration. This study focused on gelatin methacryloyl (GelMA) as a scaffold material. We developed GelMA (GelMA-RF) that gelated under visible light, avoiding the disadvantage of UV irradiation in conventional methods, and used it as a scaffold for cell transplantation. Furthermore, considering the increasing need for regenerative medicine in elderly patients, this study focused on using immature-osteoblasts derived from aged individuals as transplant cells to verify the bone regenerative capacity. In this study, immature-osteoblasts isolated from the alveolar bone of aged rats were encapsulated in GelMA-RF and transplanted into bone defects, confirming early bone regeneration sufficiently. Furthermore, in vitro analysis confirmed bone formation-related gene expression and calcification capacity, demonstrating that GelMA-RF is a suitable material for bone regeneration. These findings suggest that even alveolar bone immature-osteoblasts derived from aged individuals, when combined with GelMA-RF, hold promise as a novel therapeutic approach for regenerating complex and extensive bone defects.