Synthesis of chitosan/hydroxyapatite/Fe3O4 microspheres with NIR-induced antibacterial property

Biopolymer/hydroxyapatite composites are one type of the most promising bone tissue regenerative materials because of their excellent biocompatibility, tailored biodegradability, and strong osteo-conductivity. However, their antibacterial property is still very limited. Here, the chitosan/hydroxyapatite/Fe3O4 microspheres were prepared via the water/oil emulsion technique and their photothermal antibacterial property were investigated. SEM observations showed that the as-synthesized microspheres were spherical in morphology and had a diameter of 10–50 µm. XRD patterns indicated that both Fe3O4 and HAp components were involved in the as-synthesized microspheres. Under near-infrared (NIR) light irradiation, the microspheres were NIR-responsive and showed photothermal property due to the involvement of Fe3O4. Further, the microspheres effectively killed Escherichia coli (model bacteria) under 808 nm-NIR laser irradiation. Thus, the present microspheres have potential as antibacterial biomaterials for biomedical applications.