Preparation and characterization of the catechol functionalized chitosan-Ag NPs deposited onto titanium surface

The bacterial infection is one of the main reasons for the failure of implant surgery. In this paper, catechol functionalized chitosan (CSCT) was used as a reducing agent and stabilizer to synthesize CSCT-Ag NPs. The composite coating of titanium surface was then electrodeposited by a CSCT layer initially, followed by spincoating of a CSCT/gelatin (G)/CSCT-Ag NPs layer. The results of XRD, UV-Vis, and TEM showed that the silver nanoparticles were successfully synthesized with uniform distribution, and the particle size was 4-22 nm. The cytotoxicity test results of CSCT-Ag NPs on A549 and EA.Hy926 cells showed when the concentration of CSCT-Ag NPs was less than 25 mu g/mL, the survival rate of the two kinds of cells was greater than 80%. First electrodeposition and then spin-coating is feasible through the coating adhesion test and the adhesion level up to 5B. Compared with the pure Ti substrate, the corrosion resistance and hydrophilicity of the composite coating surface are significantly improved. The antibacterial rate of the composite coating against E. coli and S. aureus can reach 99% and 96%. In conclusion, CSCT-Ag NPs and the method of preparing coatings by electrodeposition and then spin-coating have good clinical application potential.