Local Delivery of Exosomes and Antibiotics in Hydroxyapatite-Based Nanocement for Osteomyelitis Management.

The management of bone and joint infections is a formidable challenge in orthopedics and poses a global health concern. While clinical management emphasizes infection prevention and complete eradication, an effective strategy for stabilizing skeletal tissue with adequate soft tissue coverage remains limited. In this study, we have employed a novel approach of using the local delivery of exosomes and antibiotics (rifampicin) using a hydroxyapatite-based nanocement carrier to manage the residual space created during debridement effectively. Additionally, we synthesized a periosteum-guiding antioxidant herbal membrane to leverage the inherent periosteum regeneration capability of the bone, facilitating bone callus repair and natural healing. The synthesized scaffolds were biocompatible and demonstrated potent antibacterial activity in vitro. When evaluated in vivo in the Staphylococcus aureus-induced rat tibial osteomyelitis model, the released drugs successfully cleared the residual bacteria and the released exosome promoted bone healing, resulting in 3-fold increase in bone volume as analyzed via micro-CT analysis. Immunofluorescence staining of periosteum-specific markers also indicated the complete formation of periosteal layers, thus highlighting the complete bone repair.