Bacterial adhesion-mediated physical removal of pathogens with a cotton-based dressing for infected wound management...

Antimicrobial agent-loaded wound dressings clear bacteria effectively but hinder healing via toxins from dead bacteria. To solve this, we proposed a new strategy for reducing microbial load in wounds based on physical adhesion and removal. By precisely regulating the surface properties of materials to make them highly adhesive to bacteria while keeping bacteria alive, pathogens can be physically removed when changing dressings, thereby controlling infection without triggering toxin release. To validate this strategy, we constructed a library of material models with tunable surface properties related to bacterial adhesion, by modifying cotton fabrics with alkyl chlorides of different chain lengths to yield esterified cotton fabrics. Systematic screening of the esterified cotton fabrics revealed that optimal adhesion was achieved when surface free energy (SFE), hydrophilicity, and roughness were well-balanced; moreover, the adhesion differences among the various fabric types were primarily determined by surface roughness. Based on this, an acetyl chloride-modified cotton-based spunlace nonwoven dressing was fabricated, with the 0.5% grafting rate (ACMNW_0.5%) exhibited the best bacteria adhesion ability. Within 12 h, this dressing adhered to S. aureus and E. coli at densities of 6.23 × 10⁸ CFU/cm² and 9.82 × 10⁵ CFU/cm², respectively, while maintaining ideal biocompatibility and low wound adhesion. In vivo studies showed that ACMNW_0.5% accelerates healing by clearing bacteria, mitigating inflammation, and promoting growth factor expression. This study not only provides an effective new way for the development of antibiotic-free wound dressings, but also lays a theoretical foundation for the design of fiber materials with directional bacterial adhesion function.