Bone induction following surgical implatation of block and particulated biphasic calcium phosphate coated with Escherichia coli derived rhBMP-2 in rat calvarial defects

Abstract

[한글]

[영문]The delivery systems and production efficiency have become more significant factors with increasing clinical application of recombinant human bone morphogenetic protein-2 (rhBMP-2). In this aspect, the objective of this study was to evaluate bone formation in rat calvarial defects following surgical implantation of block or particulated type biphasic calcium phosphate (BCP) coated with Escherichia coli derived rhBMP-2 (ErhBMP-2). Critical-size calvarial osteotomy defects were created in five groups of Sprague-Dawley rats. Each group received one of the following: 1) sham surgery control, 2) biphasic calcium phosphate particles (CPP), 3) biphasic calcium phosphate block (CPB), 4) ErhBMP-2 coated CPP, 5) ErhBMP-2 coated CPB. ErhBMP was coated on BCP by stepwise lyophilizing protocol. Each animal was evaluated by histologic and histometric parameters after a 2- or 8-week healing interval. The new bone formation was significantly greater in ErhBMP-2-treated groups compared to the untreated group. In particular, the CPB/ErhBMP-2 group showed the stability of augmented areas during the period of healing, due to relevant space-providing capacity. Thus, it can be concluded that ErhBMP-2-coated CPP and CPB enhance the formation of new bone, and CPB appears a suitable carrier for ErhBMP-2 in which a 3-dimensional stuructural integrity is an important consideration factor.