Construction of porous chitosan-based organic/inorganic composite with synergistic antibacterial activity

The increasing resistance of antibiotics and the global spread of pathogenic bacteria highlight the urgent need for novel antibacterial materials. In this study, a terpolymer (PVBA) with carboxyl (-COOH) and benzyl chloride (-C7H6Cl) groups was synthesized using acrylic acid (AA), butyl acrylate (BA), and 4-vinyl benzyl chloride (VBC) as monomers. The -C7H6Cl groups in the PVBA terpolymer was then reacted with N-N-dimethylhexadecane 1-amine (HAM) to prepare a more hydrophilic antibacterial (PVBA-N) terpolymer. Further, a synthetic/natural (PVBA-N/C) composite with quaternary ammonium (QA) groups was prepared by covalent crosslinking of the PVBA-N terpolymer and chitosan (CS). Finally, the AgCl-decorated PVBA-N/C (AgCl@PVBA-N/C) antibacterial composite was were constructed by anchoring silver chloride nanoparticles (AgClNPs) to the surface of the PVBA-N/C composite. Remarkably, the resulting AgCl@PVBA-N/C antibacterial composite had a porous network structure and exhibited favorable antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) based on both contact-typed and release-typed antibacterial modes, and low cytotoxicity against L929 cells. This research provides an effective strategy to combat the threat of bacterial resistance to human health relying on the advantage of the respective antibacterial mechanisms of various antibacterial ingredients.