Photo-immobilization of bone morphogenetic protein-2 using azidophenyl gelatin on a collagen sheet enhances osteogenesis in a rat calvarial defect model

Twenty-eight rats were randomized into two groups: a control group comprising a collagen sheet with only cast BMP-2; and an experimental group comprising a collagen sheet with BMP-2 photo-immobilized using azidophenyl gelatin. Micro-computed tomography analysis revealed that there was more regenerated bone in experimental group at both 4 and 8 weeks. Immunohistochemical analysis revealed that the positively expressed cellular ratio in RUNX2-stained cells were significantly higher in experimental group. These results demonstrate that BMP-2 photo-immobilized using Az-Gel on a collagen sheet shows promising bone regeneration, and the sheet is a good candidate of BMP-2 carrier.