Multifunctional chitosan-copper-gallic acid based antibacterial nanocomposite wound dressing

Antibacterial wound dressings can effectively avoid the residual of antibacterial nanomaterials for injection in vivo, reduce their biological toxicity to normal cells and tissues, making them be widely applied in biomedical field. Herein, an approach of combining ion-crosslinking, in-situ reduction and microwave-assisted methods was employed to prepare chitosan-copper-gallic acid nanocomposites (CS-Cu-GA NCs) with dual-functional nano-enzyme characteristics (oxidase- and peroxidase-like functions). The oxidase-like activity of CS-Cu-GA NCs can facilitate the production of hydrogen peroxide (H2O2) when it contacted with physiologically relevant antioxidants (AH2) in bacteria. Subsequently, H2O2 was catalyzed to generate hydroxyl radicals (OH) under the peroxidase-like activity of CS-Cu-GA NCs. Furthermore, CS-Cu-GA NCs integrate the inherent antibacterial properties of chitosan, Cu NPs and Cu2+. Animal experiments revealed that the antibacterial dressing incorporating CS-Cu-GA NCs exhibited its effective promotion of S. aureus-infected wounds healing, as well as no damage to normal tissues. Besides, the antibacterial dressing was prepared to a band aid with excellent water swelling and antibacterial properties, which was further fixed in a medical tape to construct a portable antibacterial product that can be applied to the surface of human skin and showed excellent waterproof performance, providing a new insight for the construction of clinical antibacterial wound healing products.