Enhanced underwater adhesion of chitooligosaccharide-based pressure-sensitive adhesives and their potential in wound...

Achieving strong and biocompatible underwater adhesion remains a major challenge for medical pressure-sensitive adhesives (PSAs), due to the inherent trade-offs between interfacial adhesion, cohesive strength, and bioactivity. Here, we report the design of a multifunctional chitosan-based PSA that integrates biocompatible chitooligosaccharide (COS) backbones with hydrophobic poly(trimethylene carbonate) (PTMC) side chains to enhance cohesive energy, and catechol-functionalized gallic acid (GA) moieties to improve underwater interfacial adhesion. Molecular dynamics simulations revealed that catechol groups effectively disrupt interfacial hydration layers, enabling closer contact with tissue surfaces. The optimized adhesive (CPG) exhibited strong wet adhesion, with a shear strength of 17.7 kPa and a burst pressure of 31.3 kPa, outperforming commercial fibrin glue. In vitro assays showed good cytocompatibility, low hemolysis (<2%), and antibacterial activity. Moreover, in vivo studies in a rat skin wound model indicated that CPG supported tissue regeneration by modulating inflammation, reducing oxidative stress, and promoting neovascularization. These findings suggest that CPG holds potential for biomedical applications requiring reliable underwater adhesion and tissue compatibility.