title: In vitro characterization of an osteoinductive biphasic calcium phosphate in combination with recombinant BMP2.
abstract: BACKGROUND
  The repair of alveolar bone defects with growth factors and bone grafting materials has played a pivotal role in modern dentistry. Recombinant human bone morphogenetic protein-2 (rhBMP2), an osteoinductive growth factor capable of cell recruitment and differentiation towards the osteoblast lineage, has been utilized in combination with various biomaterials to further enhance new bone formation. Recently, a group of novel biphasic calcium phosphate (BCP) bone grafting materials have been demonstrated to possess osteoinductive properties by demonstrating signs of ectopic bone formation. The aim of the present study was to study the effects of rhBMP2 in combination with osteoinductive BCP bone grafts on osteoblast cell behaviour.
  
  
  METHODS
  MC3T3-E1 pre-osteoblasts were seeded on 1) control tissue culture plastic, 2) 10 mg of BCP alone, 3) 100 ng rhBMP2, and 4) 100 ng rhBMP2+ 10 mg of BCP and analyzed for cell recruitment via a Transwell chamber, proliferation via an MTS assay and differentiation as assessed by alkaline phosphatase (ALP) activity, alizarin red staining and real-time PCR for osteoblast differentiation markers including Runx2, collagen1, ALP, and osteocalcin (OCN).
  
  
  RESULTS
  rhBMP2 was able to significantly upregulate cell recruitment whereas the addition of BCP as well as BCP alone had no additional ability to improve osteoblast recruitment. Both BCP and rhBMP2 were able to significantly increase cell proliferation at 3 and 5 days post seeding and cell number was further enhanced when rhBMP2 was combined with BCP. In addition, the combination of rhBMP2 with BCP significantly improved ALP activity at 7 and 14 days post seeding, alizarin red staining at 14 days, and mRNA levels of Runx2, ALP and osteocalcin when compared to cells seeded with rhBMP2 alone or BCP alone.
  
  
  CONCLUSIONS
  The results from the present study demonstrate that 1) the osteoinductive potential of BCP bone particles is equally as osteopromotive as rhBMP2 on in vitro osteoblast differentiation and 2) BCP particles in combination with rhBMP2 is able to further increase the osteopromotive differentiation of osteoblasts in vitro when compared to either rhBMP2 alone or BCP alone. Future animal testing is further required to investigate this combination approach on new bone formation.
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan, 430079, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Shuang
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan, 430079, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yizhen
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan, 430079, People's Republic of China. zyf@whu.edu.cn.|Department of Oral Implantology, School of Stomatology, Wuhan University, Wuhan, 430079, People's Republic of China. zyf@whu.edu.cn.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Bern University Hospital, Inselspital, Bern, 3010, Switzerland.|Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University, 3-18-15 Tokushima, Tokushima, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Fujioka-Kobayashi
authors.affiliation: Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, Bern, 3010, Switzerland.
authors.forename: Anton
authors.initials: A
authors.lastname: Sculean
authors.affiliation: Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, Bern, 3010, Switzerland. Richard.miron@zmk.unibe.ch.|Department of Periodontology, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, FL, 33328, USA. Richard.miron@zmk.unibe.ch.|Department of Oral Surgery and Stomatology, University of Bern, Bern, Switzerland. Richard.miron@zmk.unibe.ch.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Miron
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002454:Cell Differentiation; D006801:Humans; D006882:Hydroxyapatites / Q000494:pharmacology*; D010006:Osteoblasts; D010012:Osteogenesis; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: D055396:Bone Morphogenetic Protein 2; D006882:Hydroxyapatites; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C074950:hydroxyapatite-beta tricalcium phosphate; C499469:recombinant human bone morphogenetic protein-2
keywords: BCP; Bone morphogenetic protein; Growth factors; Guided bone regeneration; Vivoss