Preparation of AgBrNPs@copolymer-decorated chitosan with synergistic antibacterial activity

Abstract

The disease transmission and cross-infection caused by drug-resistant bacteria have posed serious threats to public health, and the development of new antibacterial materials without inducing drug resistance has attracted great attention. Herein, an amphiphilic (PGBA) copolymer with sodium sulfonate groups and epoxy groups was first obtained by solution polymerization. Then, the PGBA copolymer-decorated chitosan (PGBA-N/C) composite was further prepared by covalent cross-linking of the epoxy groups of the PGBA copolymer and the amino groups of the chitosan (CS), as well as the ion exchange reaction between sodium sulfonate groups in PGBA copolymer with cetyltrimethylammonium bromide (CTAB). Finally, an organic/inorganic antibacterial (AgBr@PGBA-C/N) composite with contact/release mechanism was successfully synthesized by loading silver bromide nanoparticles (AgBrNPs) on its structural surfaces. The results revealed that the resultant AgBr@PGBA-C/N composite possessed low cytotoxicity against L929 cells at its concentrations lower than 128 μg/mL, while had better bactericidal effects at its concentrations higher than 128 μg/mL against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Overall, the rational design of combination strategies, utilizing the antibacterial advantages of different materials，will be conducive to resisting widespread bacterial infections and delaying the progression of drug-resistant bacteria.