Influence of bone morphogenetic protein and proportion of hydroxyapatite on new bone formation in biphasic calcium phosphate graft: Two pilot studies in animal bony defect model

• Published in: Journal of cranio-maxillo-facial surgery 2014-12, Vol.42 (8), p.1909-1917
• Main Authors: Yun, Pil-Young, Kim, Young-Kyun, Jeong, Kyung-In, Park, Ju-Cheol, Choi, Yeon-Jo
• Format: Article
• Language: English
• Subjects: Animals; Beta-tricalcium phosphate; Biphasic calcium phosphate; Bone Diseases - pathology; Bone Diseases - surgery; Bone morphogenetic protein; Bone Morphogenetic Protein 2 - chemistry; Bone Morphogenetic Protein 2 - therapeutic use; Bone Substitutes - chemistry; Bone Substitutes - therapeutic use; Collagen; Collagen Type I - chemistry; Dentistry; Disease Models, Animal; Dogs; Hydroxyapatite; Hydroxyapatites - chemistry; Hydroxyapatites - therapeutic use; Imaging, Three-Dimensional - methods; Mandible - pathology; Mandibular Diseases - pathology; Mandibular Diseases - surgery; Osteogenesis - drug effects; Pilot Projects; Porosity; Rabbits; Recombinant Proteins - chemistry; Recombinant Proteins - therapeutic use; Skull - pathology; Skull - surgery; Surgery; Time Factors; Tissue Scaffolds - chemistry; Tooth Socket - pathology; Tooth Socket - surgery; Transforming Growth Factor beta - chemistry; Transforming Growth Factor beta - therapeutic use; X-Ray Microtomography - methods
• ISSN: 1010-5182; 1878-4119
• DOI: 10.1016/j.jcms.2014.07.011

Abstract Purpose The purpose of these two pilot studies using animal bony defect models was to evaluate the influence of bone morphogenetic protein (BMP) and proportion of hydroxyapatite (HA)/beta-tricalcium phosphate (β-TCP) in biphasic calcium phosphate (BCP) graft on new bone formation. Methods In this study, four kinds of synthetic osteoconductive bone materials known for bone growth scaffold, OSTEON™II(HA:β-TCP 30:70), OSTEON™III (HA:β-TCP 20:80), OSTEON™II Collagen, and OSTEON™III Collagen, were prepared as BCP graft materials. In pilot study 1, three BCP materials (OSTEON™II, OSTEON™III, and OSTEON™II Collagen) were grafted in rabbit calvarial defects after impregnating in rhBMP-2. OSTEON™II without the rhBMP-2 impregnation was included in the study as the control. The amount of new bone was examined and measured histologically at 2, 4, and 8 weeks. In pilot study 2, four BCP materials (OSTEON™II, OSTEON™III, OSTEON™II Collagen, and OSTEON™III Collagen) were grafted in beagle dog mandibular defects after soaking in the rhBMP-2. The amount of total bone and new bone were measured three-dimensionally using microCT and healing process was examined histologically at 2, 4, and 8 weeks. Results In pilot study 1, rhBMP-2 impregnated groups showed more new bone formation than the rhBMP-2 free group. In pilot study 2, increased new bone formation was observed in time-dependent manner after graft of BCP and BCP-collagen (OSTEON™II, OSTEON™III, OSTEON™II Collagen, and OSTEON™III Collagen) impregnated with rhBMP-2. Also, BCP with a higher proportion of HA (30% HA) showed more favorable result in new bone formation and space maintenance, especially at the 8 weeks. Conclusion From the results of the pilot studies, rhBMP-2 played positive roles in new bone formation and BCP could become a scaffold candidate for rhBMP-2 impregnation to induce new bone formation. Moreover, BCP with a higher proportion of HA (30% HA) could be considered more appropriate for rhBMP-2 carrier.