Engineering Copper Nanoparticle/Polysaccharide-immobilized Cotton Gauze for Accelerated Healing of Staphylococcus aureus-infected Dermal Wounds

Abstract

Bacterial infection remains a major challenge in wound management, often leading to delayed healing, prolonged treatment, and increased healthcare costs. Antimicrobial dressings provide an effective approach to prevent and control wound infections. Although many antimicrobial dressings are commercially available and/or widely studied, most are either loaded with antibiotics, which raise concerns about antibiotic resistance, or contain silver nanoparticles (Ag NPs), which acts as an anti-infective but does not promote healing. This work presents a method for developing an antimicrobial, antibiofilm, biocompatible, and wound-healing promoting dressing by functionalizing the surface of cotton gauze (CG) with a combination of two polysaccharides, N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC) and Dextran, and copper nanoparticles (Cu NPs). Systematic characterization revealed that the antibacterial performance of the modified CG is influenced by the size of immobilized Cu NPs, Cu loading, and consequently Cu release. The modified gauze demonstrated excellent antibacterial activity, ranging from ~4-log to >5-log reduction in viable S. aureus. In addition, the dressing demonstrated sustained Cu release, high cytocompatibility, and supported cell migration in vitro.Importantly, in vivo studies using the S. aureus-infected rat wound model revealed that the modified CG dressing outperformed a commercial silver-based anti-infective dressing by significantly reducing bacterial load, accelerating tissue regeneration, and suppressing inflammation. Overall, this study provides important insights into Cu NP-functionalized CG and highlights its potential as an effective antimicrobial dressing for the management of infected wounds.