Researchers at Tokyo Medical and Dental University have injected a gelatin-based gel carrying the peptide OP3-4 and recombinant human bone morphogenetic protein 2 (BMP-2) into the jawbones of mice to trigger local augmentation of bone around the injection site, promising potential nonsurgical treatment for alveolar bone loss.
BMP-2 has been used before to stimulate osteogenesis in humans, but high levels can cause inflammation and tumor development. OP3-4, meanwhile, has been shown to inhibit bone decay and stimulate the differentiation of cells that form bone.
By injecting these agents, the researchers avoided the need for surgical implantation, swelling, and other complications. They saw a region of increased bone mass around the BMP-2 and OP3-4 injection site that was larger than that seen in mice injected with BMP-2 alone or with other controls.
Additionally, the mass had significantly higher bone mineral content and density. Microscopic examination revealed the deposition of calcified tissue, or mineralization, throughout the newly formed bone of the mice treated with BMP-2 and OP3-4.
“Mineralization of the outer region evidently took place before that of the inner region,” said lead author Tomoki Uehara. “We speculate that the size of the new bone is determined before calcification starts and that OP3-4 plays an important role in making a regeneration site at the early stage of bone formation.”
“OP3-4 further enhanced the number of bone-forming cells induced by BMP-2 treatment and greatly increased the expression of genetic markers of bone formation,” said corresponding author Kazuhiro Aoki, DDS, PhD.
The study, “Delivery of RANKL-Binding Peptide OP3-4 Promotes BMP-2-Induced Maxillary Bone Regeneration,” was published by the Journal of Dental Research.