The mussel-inspired GelMA/dopamine/hyaluronic acid composite hydrogel dressing for wet surface adhesion.

Tissue adhesives have attracted wide attention as alternatives to sutures. Further developments in adhesives with excellent adhesion and biocompatibility for wet tissue surfaces are still required. This study provides a new solution for the development of bioadhesives for use on tissue surfaces under wet conditions. In this study, a novel adhesive composite hydrogel (GDHA) consisting of methacrylated gelatin (GelMA), hyaluronic acid (HA) and dopamine (DA) is developed by Schiff base reaction and photo-crosslinking. A series of experiments including material characterization, mechanical tests, biocompatibility test and experiments in mice have been done to evaluate the proposed dressing. The results show that GDHA composite hydrogel dressing retains the photo-crosslinking properties of GelMA, which makes it easier to be prepared. In addition, the dressing overcomes the easy oxidation disadvantages of existing mussel-inspired adhesives by grafting DA onto HA, which makes it adhere more stable, especially for wet surfaces. Besides, the GDHA hydrogel exhibits excellent biocompatibility and it could promote wound healing by reducing inflammatory cells and accelerating collagen deposition in a full-layer skin wound mode of mice. These results suggest that the GDHA hydrogel with stable adhesion and great biocompatibility is an alternative for wet surface, presenting potential clinical applications.