title: Hyperbaric oxygen therapy accelerates osteoblast differentiation and promotes bone formation.
abstract: OBJECTIVE
  Hyperbaric oxygen therapy (HBO) has been used as an adjunctive therapy in the treatment of radiotherapy or bisphosphonate-induced osteonecrosis of the jaw however the effect of HBO on osteoblast formation and mineralisation has not been extensively studied. The current study therefore examined the effects of HBO, elevated pressure or elevated oxygen alone on osteoblast differentiation and bone nodule formation.
  
  
  METHODS
  Saos-2 human osteoblast cells were exposed to HBO (2.4 ATA, 97.9% O2, 90 min per day), elevated pressure alone (2.4 ATA, 8.8% O2, 90 min per day) or elevated oxygen alone (1 ATA, 95% O2, 90 min per day) after culturing under normoxic or hypoxic conditions and osteoblast differentiation and bone formation assessed by alkaline phosphatase activity and calcein incorporation. Expression of key regulators of osteoblast differentiation and bone matrix proteins were assessed by quantitative PCR.
  
  
  RESULTS
  Daily exposure to HBO accelerated the rate of osteoblast differentiation as determined by increased alkaline phosphatase activity and expression of type I collagen and Runx-2 mRNA during the early stages of culture. HBO also augmented bone nodule formation in hypoxic conditions. HBO had a more pronounced effect on these key markers of osteoblast differentiation than elevated oxygen or pressure alone.
  
  
  CONCLUSIONS
  The data from this study shows that daily HBO treatment accelerated the rate of osteoblast differentiation leading to an increase in bone formation.
  
  
  CONCLUSIONS
  These studies add to our understanding of HBO's reparative action in osteonecrotic bone loss. In addition to stimulating angiogenesis HBO may also improve surgical outcomes through a direct beneficial effect on osteoblast differentiation generating a larger bone mass available for reconstruction.
authors.affiliation: School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, UK.
authors.forename: Hadil
authors.initials: H
authors.lastname: Al Hadi
authors.affiliation: DDRC Healthcare, Plymouth, Devon PL6 8BU, UK.
authors.forename: Gary R
authors.initials: GR
authors.lastname: Smerdon
authors.affiliation: School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, UK. Electronic address: simon.fox@plymouth.ac.uk.
authors.forename: Simon W
authors.initials: SW
authors.lastname: Fox
mesh_terms: D002113:Calcification, Physiologic; D002460:Cell Line; D006801:Humans; D006931:Hyperbaric Oxygenation; D000860:Hypoxia / Q000473:pathology; D010006:Osteoblasts / Q000166:cytology*; D010012:Osteogenesis
keywords: Bone formation; Hyperbaric oxygen therapy; Osteonecrosis of the jaw