Electrophoretic deposition of photothermal responsive antibacterial coatings on titanium with controlled release of silver ions

Burst release of antibacterial agents generated by the surface antibacterial modification of Ti implants frequently results in a reduction in their biocompatibility and substantial toxic side effects. In this study, core-shelled nanoparticles namely AgNR@MSN, were synthesized successfully by mesoporous silica shell in-situ encapsulated Ag nanorods, and then co-deposited with chitosan to form a AgNR@MSN-chitosan composite coating on Ti substrate by electrophoretic deposition. The developed composite coating, due to the presence of AgNR, presented excellent photothermal effect under the irradiation of an 808 nm near-infrared laser, leading to both rapid increase of local temperature and triggered release of Ag ions for bacterial-killing effect against both E. coli and S. aureus. The addition of AgNR@MSN also improved the wettability of the coating and the MSN shell with mesoporous tunnels could barrier the contact and release rate of Ag to improve the biocompatibility. The developed photothermal responsive coating could be considered as a promising platform for achieving controlled release of Ag ions with outstanding antibacterial and biocompatible properties.