Multifunctional Gastrodia elata polysaccharide-based triple-network hydrogel promotes Staphylococcus aureus infected...

Bacterial infections and excessive inflammation represent significant challenges in diabetic wound healing, severely impairing tissue repair. To address these issues, functional dressings with antibacterial and anti-inflammatory properties show great value. Based on this, we developed a new multifunctional hydrogel dressing composed of Gastrodia elata polysaccharide (GEP)/gelatin methacrylated (GM) loaded with glycyrrhizic acid/iron (GF) nanoparticles to enhance Staphylococcus aureus (S. aureus) infected diabetic wound healing and mitigate bacterial infections. The hydrogel formed dynamic Schiff-base bonds between aldehyde groups of oxidized GEP (OGEP) and amino residues of GM, combined with photo-crosslinked GM networks to create a secondary interpenetrating polymer structure. Meanwhile, hydrogen bond networks were introduced through the doping of GF nanoparticles. In consequence, a triple-network system consisting of Schiff-base bonds, photo-crosslinks, and hydrogen bonds was formed. This unique multi-crosslinked design not only endowed the hydrogel with excellent mechanical properties but also enabled rapid antibacterial, antioxidative, and hemostatic capabilities. In diabetic mouse model with infected wounds, the hydrogel effectively modulated the inflammatory microenvironment by promoting macrophage polarization toward the M2 phenotype, thereby alleviating excessive inflammation. It also reduced bacterial load, relieved oxidative stress, and accelerated angiogenesis, significantly promoting wound healing and achieving complete re-epithelialization within 14 days.