Abstract: 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 μg?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.

Key words: Antibacterial bone cement, Nano-hydroxyapatite/polyurethane, Enoxacin, Shear-thinning behavior, Osteogenesis