title: Bone morphogenetic protein-2 loaded poly(D,L-lactide-co-glycolide) microspheres enhance osteogenic potential of gelatin/hydroxyapatite/β-tricalcium phosphate cryogel composite for alveolar ridge augmentation.
abstract: OBJECTIVE
  Sufficient bony support is essential to ensure the success of dental implant osseointegration. However, the reconstruction of vertical ridge deficiencies is still a major challenge for dental implants. This study introduced a novel treatment strategy by infusing poly(D,L-lactide-co-glycolide) (PLGA) microspheres encapsulating bone morphogenetic protein-2 (BMP-2) within a gelatin/hydroxyapatite/β-tricalcium phosphate (gelatin/HA/β-TCP) cryogel composite to facilitate supra-alveolar ridge augmentation.
  
  
  METHODS
  The gelatin scaffold was crosslinked using cryogel technique, and HA/β-TCP particles were mechanically entrapped to form the gelatin/HA/β-TCP composite. Co-axial electrohydrodynamic atomization technology was used to fabricate PLGA microspheres encapsulating BMP-2. The composites of gelatin/HA/β-TCP alone, with infusion of BMP-2 solution (BMPi) or microspheres (BMPm), were fixed on rat mandibles using a titanium mini-implant for 4 weeks, and the therapeutic efficiency was evaluated by micro-computed tomography, bone fluorochrome, and histology.
  
  
  RESULTS
  The gelatin/HA/β-TCP composite was homogenously porous, and BMP-2 was sustained release from the microspheres without initial burst release. Ridge augmentation was noted in all specimens treated with the gelatin/HA/β-TCP composite, and greater bone deposition ratio were noted in Groups BMPi and BMPm. Compared with Group BMPi, specimens in Group BMPm showed significantly greater early osteogenesis and evident osseointegration in the supra-alveolar level.
  
  
  CONCLUSIONS
  BMP-2 loaded PLGA microspheres effectively promoted osteogenic potential of the gelatin/HA/β-TCP composite and facilitated supra-alveolar ridge augmentation in vivo.
authors.affiliation: Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan; Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hao-Chieh
authors.initials: HC
authors.lastname: Chang
authors.affiliation: Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan.
authors.forename: Connie
authors.initials: C
authors.lastname: Yang
authors.affiliation: Department of Chemical and Biomolecular Engineering, College of Engineering, National University of Singapore, Singapore, Singapore; School of Chemistry, Biology and Materials Engineering, Suzhou University of Science and Technology, Suzhou, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Feng
authors.affiliation: Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Feng-Huei
authors.initials: FH
authors.lastname: Lin
authors.affiliation: Department of Chemical and Biomolecular Engineering, College of Engineering, National University of Singapore, Singapore, Singapore.
authors.forename: Chi-Hwa
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan; Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: changpc@ntu.edu.tw.
authors.forename: Po-Chun
authors.initials: PC
authors.lastname: Chang
mesh_terms: D000540:Alveolar Ridge Augmentation / Q000295:instrumentation / Q000379:methods*; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage*; D001861:Bone Regeneration; D059985:Cryogels / Q000737:chemistry*; D015921:Dental Implants; D005780:Gelatin / Q000008:administration & dosage; D006882:Hydroxyapatites / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry; D008297:Male; D008334:Mandible / Q000601:surgery; D008863:Microspheres; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017207:Rats, Sprague-Dawley; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
chemical_list: D055396:Bone Morphogenetic Protein 2; D059985:Cryogels; D015921:Dental Implants; D006882:Hydroxyapatites; C074950:hydroxyapatite-beta tricalcium phosphate; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D005780:Gelatin
keywords: bone morphogenetic protein-2; bone regeneration; dental implant; tissue engineering; tissue scaffolds