Effect of Antibacterial Enoxacin on the Properties of Injectable Nano-hydroxyapatite/Polyurethane Cement for Bone Repairing

Biomaterial-associated infection (BAI) is a kind of serious post-operative complication in orthopaedic surgery. Antibiotic-loaded bone cement shines a light on BAI prevention for convenient manipulation and complex filling. To this aim, we designed an antibacterial bone cement based on Nano-hydroxyapatite/Polyurethane (PUHA) loading with antibiotic Enoxacin (EN). The distinct shear-thinning behavior of the prepolymers was observed, indicating a good injectability. The PUHA bone cement possessed a suitable curing speed, and the addition of EN might slightly expedite the curing process and enhance the mechanical properties. The EN release profile indicated that the EN-loaded bone cement could reach the minimum inhibitory concentration in 2 h, and sustainedly released EN for almost 8 days, exhibiting an antibacterial delivery potential. Antibacterial test further confirmed the antibacterial ability of EN-loaded bone cement is in a dose-dependent manner. However, the osteogenic performance of drug-loaded bone cement with high dosage is not as good as antibacterial activity. When the EN concentration of antibacterial cement was lower than 32 mu g.mL(-1), the proliferation and osteogenic differentiation of rat mesenchymal stem cells could be significantly promoted. Overall, this study verified the potential of the EN-loaded PUHA bone cement in anti-infection and osteogenesis for bone repairing.