Bioinspired sequentially crosslinked nanofibrous hydrogels with robust adhesive and stretchable capability for joint wound dressing

Despite recent progress in hydrogel wound dressings, joint wound treatment remains an ongoing challenge due to their poor adhesive and stretchable properties. Herein, inspired by protein secretion-curing process of natural marine mussels, an adhesive nanofibrous hydrogel is developed via a sequential crosslinking strategy. Firstly, to avoid uncontrolled self-polymerization of dopamine (DA), DA grafted gelatin (GT) nanofibers are fabricated via electrospinning under pH value around 4. Further, the fibrous hydrogels are in-situ crosslinked under pH value of about 8 to strengthen the intermolecular interaction within fibers. The DA crosslinked GT fibrous hydrogels via Michael addition and Schiff base reaction exhibit superior adhesive and tensile properties which are 1.5 times and 3.1 times higher than those of GT fibrous hydrogels, respectively. The in vitro cytocompatibility tests and in vivo wound healing study further prove that GT grafted DA nanofibrous hydrogels are able to accelerate wound healing. Taken together, we demonstrate a simple and versatile strategy for generating adhesive and stretchable nanofibrous hydrogel, showing a great potential for joint wound care.