Encapsulation of ciprofloxacin in strontium doped hydroxyapatite microspheres: The enhanced antibacterial property and the alleviated cytotoxicity

Using strontium (Sr) doped hydroxyapatite (HA) microsphere is considered an effective strategy for improving cytocompatibility when filled into the bone defect. However, these microspheres require both abilities for bacteria removal and cellular compatibility. Herein, we innovatively produce the multifunctional microspheres, combining the Sr2+ 2+ with high cytocompatibility and the broad-spectrum antibacterial ciprofloxacin (CIP) by hydrothermal method. Characterized by FT-IR, XRD, SEM, and EDS, CIP-Sr-HA microspheres were successfully prepared with balanced antibacterial properties (against E. coli and S. aureus over 99.99 %) and biocompatibility. Activity of cells cultured in CIP-Sr-HA microspheres (115.72 %) was higher than that of pure HA microspheres (107.28 %), offering promise for infected bone defect treatment.