Synthesis of near-infrared responsive gold nanorod-doped gelatin/hydroxyapatite composite microspheres with controlled photo-thermal property

Gelatin/hydroxyapatite (HAp) composites are of great interest in the biomedical applications because of their excellent biocompatibility, biodegradability, and bioactivity. However, little attention has been paid to synthesis of the gelatin/HAp composites with photo-thermal property. In this study, near-infrared (NIR) responsive gold nanorod (GNR) doped gelatin/HAp composite microspheres were synthesized via an emulsion technique and their microstructure and NIR-responsive photo-thermal property were investigated. SEM observations showed that the composite microspheres were spherical and their diameter was ranged from 10 to 50   µm. XRD patterns showed that the composite microspheres presented the typical diffraction peaks of HAp and GNR components. FT-IR spectra showed that P-O-P bonds, -COOH groups and –NH 2 groups were involved in the composite microspheres. Under an 808-nm NIR light irradiation, the temperature of the suspension of composite microspheres was increased from 37   °C to 42   °C due to the presence of GNR component, indicating that the composite microspheres possessed NIR-responsive photo-thermal property.