Enhancing wet adhesion in biodegradable hydrogels via water-absorbent integration

Wet-adhesive hydrogels hold significant promise for biomedical applications, yet achieving long-term adhesion remains a major challenge in biodegradable systems. Here, we present a biodegradable hydrogel incorporating a water-absorbent layer to regulate swelling behavior and water content. Comprising a poly(ethylene glycol) diacrylate (PEGDA)–gelatin matrix with a starch-based absorbent layer, the hydrogel exhibits high wet adhesion energy, elevated burst pressure, effective in vivo hemostasis, and mechanical compatibility with soft tissue. This water-absorbent strategy provides a new avenue for achieving sustained and stable wet tissue adhesion in biodegradable hydrogel systems. Graphical abstract