Antibody Mediated Osseous Regeneration (AMOR) in Conjunction With Decortication in Rabbit Calvaria Model

Abstract

This study aimed to assess the osteogenic potential of chimeric monoclonal antibodies targeting BMP-2 (Anti-BMP-2 mAb) in conjunction with decortication in a rabbit calvaria model using titanium domes. Anti-BMP-2 mAb and an isotype matched control mAb were immobilized on anorganic bovine bone mineral with 10% collagen scaffold (ABBM-C) and placed within titanium domes positioned over rabbit calvaria (n = 6), with surfaces either decorticated or intact. Four groups were defined: (1) anti-BMP-2 mAb + decortication (AMD); (2) anti-BMP-2 mAb + no-decortication (AM); (3) isotype matched control mAb + decortication (IsoD); (4) isotype matched control mAb + no-decortication (Iso). After 3 months, rabbits were euthanized, and histologic observation and histomorphometric analysis were performed. ANOVA assessed group differences. Vital bone volume for the groups was: (1) 34.2% ± 7.8%; (2) 22.3% ± 4.1%, (p < 0.02 for groups AMD vs. AM); (3) 23.4% ± 6.2%, (p < 0.04 for AMD vs. IsoD); and (4) 17.5% ± 5.9%, (p < 0.003 for groups AMD vs. Iso). All groups exhibited decreased bone formation further from the calvaria bone, yet the Anti-BMP-2 mAb + decortication group maintained 30%-40% vital bone formation within 3 mm from the calvaria bone. This study highlights the superior osteogenic efficacy of Anti-BMP-2 mAb with decortication. Decortication notably enhanced the osteogenic potential of scaffolds functionalized with Anti-BMP-2 mAb.

Keywords: BMP; bone regeneration; bone substitutes; combined antibody therapeutics; osteogenesis.