title: Novel bioresorbable strontium hydroxyapatite membrane for guided bone regeneration.
abstract: OBJECTIVE
  Membrane materials have been widely used for guided bone regeneration (GBR). However, due to bio-functional limitation of the current membranes, the ideal resorbable membrane that can stimulate bone regeneration has yet to be developed. This study seeks to investigate the effects of a strontium hydroxyapatite (SrHA)-containing membrane for GBR.
  
  
  METHODS
  Strontium hydroxyapatite powder was synthesized and mixed with gelatin solution to the final concentration of 10 mg/ml (Sr10) and 20 mg/ml (Sr20). Approximately 100-μm-thick membranes were fabricated, and the mechanical properties and strontium ion release pattern were analyzed. Rat bone marrow stromal cell (BMSC) responses were investigated in vitro. Bilaterial rat calvarial defects were used in vivo to compare the SrHA membranes against commercially available collagen membranes and evaluated radiologically and histologically.
  
  
  RESULTS
  Strontium hydroxyapatite membranes exhibited higher elasticity and strength than the collagen membrane, and slow strontium ion release was also confirmed. No BMSC cytotoxicity was found on the SrHA membranes, and the alkaline phosphatase positively stained area was significantly greater than the collagen membrane at earlier time point. At 4 weeks, both micro-CT and histological analyses revealed that the Sr20 group yielded significantly greater bone formation.
  
  
  CONCLUSIONS
  The SrHA-containing membrane developed in this study was found to be a biocompatible material that can stimulate BMSC differentiation as well as bone regeneration and maturation in rat calvarial defects at early time point compared with collagen membrane. The best result was observed in Sr20 group, which can be potentially effective for GBR.
authors.affiliation: Oral Implantology and Regenerative Dental Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Hao
authors.forename: A
authors.initials: A
authors.lastname: Acharya
authors.forename: K
authors.initials: K
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Chou
authors.forename: S
authors.initials: S
authors.lastname: Kasugai
authors.forename: N P
authors.initials: NP
authors.lastname: Lang
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival; D003094:Collagen / Q000494:pharmacology; D004548:Elasticity; D048091:Guided Tissue Regeneration / Q000379:methods*; D006882:Hydroxyapatites / Q000494:pharmacology*; D008297:Male; D008567:Membranes, Artificial; D059630:Mesenchymal Stem Cells / Q000187:drug effects*; D008855:Microscopy, Electron, Scanning; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000000981:diagnostic imaging / Q000601:surgery*; D013324:Strontium / Q000494:pharmacology*; D013499:Surface Properties; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D006882:Hydroxyapatites; D008567:Membranes, Artificial; C076185:strontium hydroxyapatite; D003094:Collagen; D013324:Strontium
keywords: bioresorbable membrane; calvarial defect; guided bone regeneration membranes; strontium hydroxyapatite