title: Recombinant human bone morphogenetic protein (rhBMP)9 induces osteoblast differentiation when combined with demineralized freeze-dried bone allografts (DFDBAs) or biphasic calcium phosphate (BCP).
abstract: OBJECTIVE
  Recently, recombinant human bone morphogenetic protein 9 (rhBMP9) has been characterized as one of the most osteogenic growth factors among the 15 human BMPs. The aim of the present study was to investigate the effects of rhBMP9 in comparison to the clinically utilized rhBMP2 on in vitro cell behavior when combined with two bone graft materials including demineralized freeze-dried bone allografts (DFDBAs) and biphasic calcium phosphate (BCP).
  
  
  METHODS
  The absorption and release kinetics of rhBMPs from DFDBA and BCP were investigated by ELISA. Moreover, murine bone stromal ST2 cell behavior was investigated on DFDBA or BCP seeded on (1) graft only, (2) rhBMP2 (10 ng/ml), (3) rhBMP2 (100 ng/ml), (4) rhBMP9 (10 ng/ml), and (5) rhBMP9 (100 ng/ml). The effects of rhBMPs on DFDBA and BCP were assessed for cell adhesion, proliferation, and osteoblast differentiation by alkaline phosphatase (ALP) activity, alizarin red staining, and real-time PCR for genes encoding Runx2, ALP, and bone sialoprotein (BSP).
  
  
  RESULTS
  While both BMPs were gradually released from DFDBA and BCP over time, significantly higher adsorption was observed on BCP when compared to DFDBA. Cell attachment and proliferation was higher on BCP with little influence of either rhBMP2/9. Despite rhBMPs having relatively no effect on cell attachment/proliferation, a pronounced and marked effect was observed on osteoblast differentiation for both rhBMP2/9. Interestingly, it was observed that rhBMP9 induced significantly higher ALP activity, alizarin red staining, and messenger RNA (mRNA) levels of ALP and BSP when compared to rhBMP2. Our results also revealed higher differentiation for rhBMP2/9 with BCP when compared to DFDBA most likely as a result of higher growth factor adsorption.
  
  
  CONCLUSIONS
  While both rhBMP2/9 combined with DFDBA or BCP induced osteoblast differentiation, rhBMP9 induced greater osteoblast differentiation when compared to rhBMP2.
  
  
  CONCLUSIONS
  rhBMP9 may be a recombinant growth factor with higher potential to induce new bone formation when compared to rhBMP2. Further in vivo studies are necessary to characterize its regenerative potential in various animal models.
authors: Department of Periodontology, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA.|Department of Cranio-Maxillofacial Surgery, Bern University Hospital, Inselspital, Bern, Switzerland.|Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors: Masako
authors: M
authors: Fujioka-Kobayashi
authors: Department of Cranio-Maxillofacial Surgery, Bern University Hospital, Inselspital, Bern, Switzerland.
authors: Benoit
authors: B
authors: Schaller
authors: Department of Oral Implantology, University of Wuhan, Wuhan, China.
authors: Yufeng
authors: Y
authors: Zhang
authors: Department of Pediatric Dentistry, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA.
authors: Umadevi
authors: U
authors: Kandalam
authors: Department of Periodontology, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA.
authors: Maria
authors: M
authors: Hernandez
authors: Department of Periodontology, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA. rmiron@nova.edu.
authors: Richard J
authors: RJ
authors: Miron
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D064591:Allografts; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology; D002113:Calcification, Physiologic / Q000187:drug effects; D002130:Calcium Phosphates / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D055427:Growth Differentiation Factor 2 / Q000494:pharmacology*; D006801:Humans; D006882:Hydroxyapatites / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000187:drug effects*; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology
chemical_list: D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D055427:Growth Differentiation Factor 2; D006882:Hydroxyapatites; D011994:Recombinant Proteins; C074950:hydroxyapatite-beta tricalcium phosphate; C000593120:maxresorb; D000469:Alkaline Phosphatase
keywords: BCP; BMP2; BMP9; Biphasic calcium phosphate; Bone morphogenetic proteins; Bone regeneration; Bone tissue engineering; DFDBA; Demineralized freeze-dried bone allografts