In vitro/in vivo comparison of cefuroxime release from poly(ε-caprolactone)-calcium sulfate implants for osteomyelitis treatment.

This study aimed to investigate the release of cefuroxime axetil (CF) and calcium from poly(ε-caprolactone) (PCL)-calcium sulfate (CaS) implants (PCL:CaS 2:1-10% CF; PCL:CaS 2:1-20% CF; PCL:CaS 1:1-10% CF) for treating infectious bone diseases. Bioactivity, crystallinity and strength, and release profiles under standard and pressurized release conditions were studied. PCL:CaS 2:1-20% CF had slower release than 10% loading. These groups had no significant change in CF and Ca release in response to pressure. The PCL:CaS 1:1 group had the slowest release despite having higher CaS, probably due to more compaction of discs. In contrast, pressure caused significant differentiation of CF and Ca(2+) release. The presence of CaS enhanced mechanical properties and bioactivity of discs. SEM and XPS results showed calcium-phosphate containing accumulations on surfaces upon SBF incubation. CF-loaded implants were applied in a rabbit osteomyelitis model. In vivo CF release was enhanced with increased CaS proportions, suggesting that in vivo release conditions are closer to pressurized in vitro conditions. In the control group, there was still some inflammation in the bone and no complete coverage with bone was achieved in the defect site. Discs provided a suitable surface for regeneration of bone. However, bone formation in the PCL:CaS 1:1 disc implanted group was more complete and regular than in the 2:1 group.