Interfacially regulated CMC/chitosan nonwoven dressings for antibacterial infected wound healing

Polysaccharide-based absorbent dressings are widely used for infected wound management due to their high fluid uptake capacity and biocompatibility; however, excessive swelling under wet conditions is often accompanied by undesirable biological responses, limiting their clinical performance. Herein, a composite nonwoven dressing composed of carboxymethyl cellulose (CMC) and silver-loaded acylated chitosan (ACS-Ag) was developed, followed by the introduction of a vaseline-derived hydrophobic/semi-occlusive interface (VCMC/ACS-Ag) to regulate interfacial behavior and fluid transport. The vaseline coating effectively suppressed excessive wet-state swelling and stabilized the fibrous network, while maintaining broad-spectrum antibacterial activity against S. aureus, E. coli, and P. aeruginosa. Compared with the uncoated system, VCMC/ACS-Ag exhibited significantly improved cytocompatibility and hemocompatibility, reducing hemolysis from 33.1% to 1.97%, which may be associated with moderated interfacial interactions under wet conditions. Moreover, the dressing promoted fibroblast migration and alleviated LPS-induced inflammatory activation in macrophages. In a S. aureus-infected full-thickness wound model, VCMC/ACS-Ag accelerated wound closure, enhanced collagen deposition and angiogenesis, and reduced local inflammation. This study provides an interfacial regulation strategy for balancing fluid management, antibacterial performance, and biosafety in advanced wound dressings.