Delivery of RANKL-Binding Peptide OP3-4 Promotes BMP-2-Induced Maxillary Bone Regeneration.

Although bone morphogenetic protein 2 (BMP-2) is known to stimulate osteogenesis, there is evidence that high doses of BMP-2 can lead to side effects, including inflammation and carcinogenesis. The supplementation of other bone-augmenting agents is considered helpful in preventing such side effects by reducing the amount of BMP-2 required to obtain a sufficient amount of bone. We recently showed that a receptor activator of nuclear factor κB ligand (RANKL)–binding peptide promotes osteoblast differentiation. In the present study, we aimed to investigate whether OP3-4, a RANKL-binding peptide, promotes BMP-2–induced bone formation in the murine maxilla using an injectable gelatin hydrogel (GH) carrier. A GH carrier containing OP3-4 with BMP-2 was subperiosteally injected into the murine maxillary right diastema between the incisor and the first molar. The mice were sacrificed 28 d after the injections. The local bone formation in the OP3-4-BMP-2–injected group was analyzed in comparison to the carrier-inje...