title: Bone Regenerative Efficacy of Limited-Dose Escherichia Coli-Derived rhBMP-2 With Biphasic Calcium Phosphate Carrier in Rabbit Calvarial Defect Model.
abstract: OBJECTIVE
  The aim of this study was to characterize the healing in rabbit calvarial bone defects after delivery of limited-dose (1.5 μg) Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2), and evaluate biphasic calcium phosphate (BCP) as a carrier.
  
  
  METHODS
  Four 8-mm diameter circular calvarial bone defects were made in 16 rabbits and filled with one of the following: (1) nothing, (2) BCP alone, (3) ErhBMP-2-loaded absorbable collagen sponge (ACS), or (4) ErhBMP-2-loaded BCP. The animals were allowed to heal for either 2 or 8 weeks and were evaluated in clinical, microcomputed tomographic, histological, and histomorphometric analyses.
  
  
  RESULTS
  Microcomputed tomography revealed extensive new bone formation in both of the limited-dose ErhBMP-2-loaded groups. However, bony collapse of the upper defect borders was found in the ErhBMP-2-loaded ACS group. Histomorphometric examination revealed significantly greater new bone formation at 8 weeks than at 2 weeks in all 4 groups (P < 0.05). Both new bone formation and the size of the augmented area differed significantly between the ErhBMP-2-loaded BCP group (6.88 ± 0.74 and 19.62 ± 0.77) and the ErhBMP-2-loaded ACS group (3.04 ± 0.27 and 5.41 ± 0.43) at 8 weeks of healing.
  
  
  CONCLUSIONS
  ErhBMP-2 promotes bone regeneration in rabbit calvarial defects, even at a limited dose (1.5 μg). The results of this study suggest that BCP is the more efficient carrier for this protein than ACS.
authors.affiliation: *Post-Graduate, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, South Korea. †Clinical Assistant Professor, Department of Periodontology, School of Dentistry, Kyung Hee University, Seoul, South Korea. ‡Clinical Assistant Professor, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, South Korea. §Associate Professor, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, South Korea. ¶Professor, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, South Korea.
authors.forename: Hoon
authors.initials: H
authors.lastname: You
authors.forename: So-Ra
authors.initials: SR
authors.lastname: Yoon
authors.forename: Hyun-Chang
authors.initials: HC
authors.lastname: Lim
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Lee
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000627:therapeutic use*; D001861:Bone Regeneration / Q000187:drug effects*; D004926:Escherichia coli / Q000378:metabolism; D006882:Hydroxyapatites / Q000627:therapeutic use*; D008297:Male; D011817:Rabbits; D011994:Recombinant Proteins / Q000627:therapeutic use; D012886:Skull / Q000254:growth & development; D055114:X-Ray Microtomography
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D006882:Hydroxyapatites; D011994:Recombinant Proteins; C074950:hydroxyapatite-beta tricalcium phosphate