Nano-engineered Ag@MgO embedded chitosan hydrogel patch for potent antibacterial activity, antibiofilm activity, and infected wound healing

Abstract

Bacterial infection and biofilm formation are major barriers to effective wound healing, often leading to persistent inflammation, delayed tissue repair, and chronic wound conditions. To address these issues, a chitosan-based hydrogel patch embedded with silver-decorated two-dimensional magnesium oxide nanosheets (Cs–AMO) was developed as a multifunctional wound dressing. Morphological analysis confirmed the formation of porous 2-D MgO nanosheets uniformly decorated with Ag nanoparticles and well dispersed within the chitosan matrix. Owing to the combined effects of Ag⁺ ion release, reactive oxygen species generation, and contact-mediated antibacterial interactions, the Cs–AMO hydrogel patch showed nearly complete antibacterial inhibition (∼100%) against both Gram-negative and Gram-positive bacteria. In addition, the hydrogel exhibited strong antibiofilm activity, achieving biofilm inhibition of up to 82% against E. coli and 83% against B. subtilis, as confirmed by crystal violet assay and confocal microscopy. Cytocompatibility studies using HEK-293 cells revealed up to 85% cell viability, indicating favourable biocompatibility. Furthermore, in vivo evaluation using an infected rat wound model demonstrated accelerated wound healing, achieving 96% wound closure by day 12 post-treatment, along with effective bacterial clearance, reduced inflammation, and enhanced tissue regeneration compared to the control groups. Overall, the developed Cs–AMO hydrogel patch demonstrates strong potential as an antibacterial and antibiofilm wound dressing for the treatment of infected wounds.