Multi-crosslinking hydrogels with robust bio-adhesion and pro-coagulant activity for first-aid hemostasis and infected wound healing

Bio-adhesive polysaccharide-based hydrogels have attracted much attention in first-aid hemostasis and wound healing for excellent biocompatibility,antibacterial property and pro-healing bioactivity.Yet,the inadequate mechanical properties and bio-adhesion limit their applications.Herein,based on dynamic covalent bonds,photo-triggered covalent bonds and hydrogen bonds,multifunctional bio-adhesive hydrogels comprising modified carboxymethyl chitosan,modified sodium alginate and tannic acid are developed.Multi-crosslinking strategy endows hydrogels with improved strength and flexibility simultaneously.Owing to cohesion enhancement strategy and self-healing ability,considerable bio-adhesion is presented by the hydrogel with a maximal adhesion strength of 162.6 kPa,12.3-fold that of commercial fibrin glue.Based on bio-adhesion and pro-coagulant activity(e.g.,the stimulative aggregation and adhesion of erythrocytes and platelets),the hydrogel reveals superior hemostatic performance in rabbit liver injury model with blood loss of 0.32 g,only 54.2%of that in fibrin glue.The healing efficiency of hydrogel for infected wounds is markedly better than commercial EGF Gel and Ag+Gel due to the enhanced antibacterial and antioxidant properties.Through the multi-crosslinking strategy,the hydrogels show enhanced mechanical properties,fabulous bio-adhesion,superior hemostatic performance and promoting healing ability,thereby have an appealing application value for the first-aid hemostasis and infected wound healing.