Effects of Hyperbaric Oxygen on Proliferation and Differentiation of Osteoblasts from Human Alveolar Bone

In view of the controversy of the clinical use of hyperbaric oxygen (HBO) treatment to stimulate fracture healing and bone regeneration, we have analysed the effects of daily exposure to HBO on the proliferation and differentiation of human osteoblasts in vitro. HBO stimulated proliferation when osteoblasts were cultured in 10% foetal calf serum (FCS), whereas an inhibitory effect of HBO was observed when cultures were supplemented with 2% FCS,. On the other hand, HBO enhanced biomineralization with an increase in bone nodule formation, calcium deposition and alkaline phosphatase activity, while no cytotoxic effect was detected using a lactate dehydrogenase activity assay. The data suggests that the exposure of osteoblasts to HBO enhances differentiation towards the osteogenic phenotype, providing cellular evidence of the potential application of HBO in fracture healing and bone regeneration.