Fabrication and characteristics of functional hydrogels based on dopamine-grafted gelatin and oxyglucan with incorporation of dipotassium glycyrrhizinate potential for wound dressings

Hydrogel have been widely used to promote skin tissue regeneration and accelerate wound healing. The development of injectable hydrogels with multi-functional integration is a priority, especially with antibacterial properties and cytocompatibility. Here, we reported a simple, and versatile method to fabricate a functional hydrogel with potential for wound dressing applications. The dopamine-grafted gelatin (GT-DA) and oxidized dextran (oxyglucan, ODex) were synthesized, and dipotassium glycyrrhizinate (DG) was in situ incorporated to fabricate the composite hydrogels (GDO) through the Schiff base reaction. SEM images revealed that hydrogel has a porous structure. By increasing the ratio of GT-DA to ODex from 1 to 4, the storage modulus (G') and hydrogel network stability nearly doubled, reaching 900 Pa and 220% strain, respectively. The enhancement in mechanical properties could be attributed to the higher cross-linking density resulting from increased Schiff base bonds in the GDO hydrogels. Furthermore, the GDO hydrogel exhibited antioxidant activity and antibacterial effects on Escherichia coli and Staphylococcus aureus . Moreover, the hydrogel demonstrated cytocompatibility after culturing with human umbilical vein endothelial cells (HUVECs). The results proved that the fabricated GDO hydrogels have the potential to be used as wound dressings.