Hyperbaric oxygen therapy (HBO) is used to treat or prevent tissue necrosis in patients undergoing irradiation. Many such patients require reconstructive surgery, but little is known of the effects of HBO on bone vascularization and regeneration.
Method:
In this study, copolymer poly(LLA-co-DXO) scaffolds were implanted into critical-sized calvarial defects in Wistar rats. The animals were randomly allotted to hyperbaric or normobaric oxygen groups. The treatment group received 5 sessions weekly for 90 minutes at increased atmospheric pressure, for up to 4 weeks. Samples were retrieved at weeks 2 and 8, i.e. after a total of 10 and 20 sessions respectively. The samples were analyzed with real-time RT-PCR and histology at week 2, and radiographically and histologically at week 8.
Result:
At week 2, defects treated with HBO exhibited greater numbers of cells positive for the endothelial marker CD31, up-regulated gene expression of osteogenic markers and down-regulated expression of pro-inflammatory cytokines. At week 8, radiographic examination revealed that calvarial defects subjected to HBO exhibited a higher percentage of radiopacities than normobaric controls, and histological examination disclosed enhanced bone healing.
Conclusion:
These results confirmed that hyperbaric oxygen treatment was effective in stimulating vascularization and bone formation in rat calvarial defects.