Injectable, self-healing, antibacterial hydrogel dressing based on oxidized dextran and sialic acid substituted chitosan with incorporation of tannic acid

[Display omitted] •Chitosan was modified using salic acid.•Injectable self-healing hydrogel was fabricated using chitosan, dextran, and tannic acid.•The obtained hydrogel possessed excellent ROS scavenging property.•The obtained hydrogel displayed antibacterial capability.•The excellent cytocompatibility of the obtained hydrogels was confirmed. Injectable self-healing hydrogels have become a promising option as wound dressings due to their soft properties similar to extracellular matrixes, adjustable physicochemical properties and ability to fill any irregularly shaped wound and matin a moist environment. In this paper, salic acid-modified chitosan (CS-SA) and oxidized-dextran (Odex) were used to fabricate CS-SA/Odex composite hydrogels via Schiff base reaction, into which plant-derived polyphenol tannic acid was incorporated. The successful synthesis of CS-SA and Odex was confirmed using H nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectrometer (FT-IR) analysis. Scanning electron microscopy (SEM) images displayed that the obtained hydrogel had an interconnected porous microstructure. In addition, the fabricated hydrogels exhibited excellent self-healing and injectable properties. Furthermore, in vitro experimental results demonstrate that the hydrogels possess excellent reactive oxygen species (ROS) scavenging and antibacterial capability and good biocompatibility after culturing with mouse embryonic fibroblast (NIH-3 T3) cells. Therefore, these findings endow the composite hydrogels with broad prospects in treating skin wounds in clinical practice.