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Bone morphogenetic binding peptide (BBP) is an 18.5 kDa fragment of a bone matrix protein peptide. A rat femoral defect model was used to test the effect of BBP combined with recombinant human bone morphogenetic protein-7 (rhBMP-7) to induced bone healing. Two doses of BBP (500 and 1000 µg) were tested with two doses of rhBMP-7 (2 and 5 µg), and the results were compared with a positive control (10 µg rhBMP-7). Bone healing was evaluated by radiology, manual palpation, microcomputed tomography, and histology. The high dose of 10 µg of rhBMP-7 resulted in a consistent 100% bone union rate and a mature histological appearance on histology, and was used as a positive control. When 1000 µg of BBP was combined with lower doses of BMP-7 (2 µg rhBMP-7 or 5 µg rhBMP-7) significant differences were seen in radiographic scores, manual palpation, and bone volume, when compared to 2 µg rhBMP-7 or 5 µg rhBMP-7 alone. The combination of 1000 µg of BBP and 5 µg rhBMP-7 also achieved 100% fusion rate, induced a larger amount of bone formation, and yielded similar maturity of bone marrow when compared with the high dosage 10 µg rhBMP-7 group. This study demonstrated that when combined together, BBP can enhance the bone healing of rhBMP-7. Improved healing imparted by the addition of BBP may result in lesser amounts of rhBMP-7 needed to achieve union in the clinical setting. © 2010 OrthopaedicResearchSociety.PublishedbyWileyPeriodicals, Inc.JOrthopRes29:753-759,2011 [ABSTRACT FROM AUTHOR]

BMP-binding peptide (BBP) enhances the osteogenic activity of recombinant human bone morphogenetic protein-2 (rhBMP-2), but the mechanism underlying the enhancement remains unclear. We aimed to elucidate the potential enhanced efficacy of BBP using critical-sized segmental femoral bone defects in rats. Seventy defects in seven groups of rats were filled with various amounts (0, 2, 5, and 10 µg) of rhBMP-2 with or without 1000 µg BBP. Radiographs were obtained after 4 and 8 weeks. The animals were euthanized at 8 weeks, and femoral specimens were assessed manually, evaluated for bone volume using microcomputed tomography, and subjected to histological or biomechanical analysis. Although 10 µg rhBMP-2 yielded consistent results in terms of bone healing and quality of bone repair across the segmental defect, lower doses of rhBMP-2 failed to induce satisfactory bone healing. However, the combined administration of lower doses of rhBMP-2 and BBP induced the formation of significantly large amounts of bone. Our results suggest that the combined administration of rhBMP-2 and BBP facilitates bone healing and has potential clinical applications. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:258-264, 2010 [ABSTRACT FROM AUTHOR]