title: Regeneration of calvarial defects with Escherichia coli -derived rhBMP-2 adsorbed in PLGA membrane.
abstract: OBJECTIVE
  Escherichia coli-derived recombinant human bone morphogenetic protein-2 (E-BMP-2) has been shown to be as effective as mammalian cell-derived BMP-2. However, several in vitro and in vivo experiments are still necessary to validate the effectiveness of E-BMP-2 due to the difference in synthesis process, mainly related to protein nonglycosylation. The objective of this study was to investigate whether biodegradable polylactide-co-glycolide (PLGA) membrane is a suitable carrier for E-BMP-2 delivery for bone regeneration of critical-sized defects in rat calvaria.
  
  
  METHODS
  First, the osteoinductive effect of E-BMP-2 was confirmed in vitro in mouse bone marrow stromal cells by analysis of osteocalcin mRNA levels, and calcium deposition was detected by alizarin red staining. Before in vivo experiments, the release profile of E-BMP-2 from PLGA membranes was determined by ELISA. E-BMP-2 (0, 1, 5 and 10 μg/μl) was applied for ectopic and orthotopic bone formation and was analyzed by X-ray, micro-CT and histology.
  
  
  RESULTS
  Release-profile testing showed that PLGA membrane could retain 94% of the initially applied E-BMP-2. Ectopic bone formation assay revealed that combination of E-BMP-2/PLGA membrane strongly induced bone formation. Stronger osteoinductivity with complete repair of critical-sized defects was observed only with PLGA membranes adsorbed with 5 and 10 μg/μl of E-BMP-2, whereas no bone formation was observed in the groups that received no membrane or 0-μg/μl dose of E-BMP-2.
  
  
  CONCLUSIONS
  PLGA membrane was shown to be a suitable carrier for sustained release of E-BMP-2, and the E-BMP-2/PLGA membrane combination was demonstrated to be efficient in bone regeneration in a model of critical-sized defects.
authors.affiliation: Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Ono
authors.forename: Wataru
authors.initials: W
authors.lastname: Sonoyama
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nema
authors.forename: Emilio Satoshi
authors.initials: ES
authors.lastname: Hara
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Oida
authors.forename: Hai Thanh
authors.initials: HT
authors.lastname: Pham
authors.forename: Katushi
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hirota
authors.forename: Kazushige
authors.initials: K
authors.lastname: Sugama
authors.forename: Walter
authors.initials: W
authors.lastname: Sebald
authors.forename: Takuo
authors.initials: T
authors.lastname: Kuboki
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage* / Q000737:chemistry*; D001861:Bone Regeneration / Q000187:drug effects*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008567:Membranes, Artificial; D051379:Mice; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry; D012886:Skull / Q000187:drug effects / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000008:administration & dosage* / Q000737:chemistry*
chemical_list: D055396:Bone Morphogenetic Protein 2; D008567:Membranes, Artificial; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid