Deposition of catechol-functionalized chitosan and silver nanoparticles on biomedical titanium surfaces for antibacterial application.

Abstract The titanium (Ti) and its alloys have been widely used for dental and orthopedic implants. However, the Ti-based implants may suffer from bacterial infection, which would result in insufficient healing, implant failure and repeated surgical intervention. It is of great interest to inhibit the bacterial adhesion and colonization on the Ti-based implants by introducing proper surface coatings. In this work, a simple method was employed to synthesize the water-soluble catechol-containing chitosan (CACS). The CACS coatings can be deposited onto various substrate surfaces and exhibit substrate-independent behavior. The CACS-coated Ti surfaces were further deposited with silver nanoparticles (Ag NPs) via in-situ reduction of Ag+ ions using catechol moieties as the reducing agents. The resulting AgNPs/CACS-coated Ti surfaces exhibit antibacterial properties and can prevent the surface adhesion of bacterial cells, as evidenced by the inhibition zone test, live/dead bacterial staining assay and spread plate method. In addition, they show negligible cytotoxicity to L929 mouse fibroblast cells. Graphical abstract Unlabelled Image Highlights • A simple method for the synthesis of water-soluble catechol-containing chitosan (CACS) was reported. • CACS can be deposited onto various surfaces and its coatings exhibit substrate-independent behavior. • The CACS coating on Ti surfaces can be used to induce the in-situ reduction of Ag+ ions. • The Ag nanoparticles- and CACS-coated Ti surfaces exhibit good antibacterial properties with low cytotoxicity. [ABSTRACT FROM AUTHOR]