Development of wound dressing using a novel multifunctional self-repairing Schiff-based N, O-carboxymethyl chitosan...

This study presents the development of self-healing, antibacterial injectable hydrogels synthesized through chemical crosslinking between the aldehyde groups of oxidized tragacanth gum (OTG) and the amino groups of N, O-carboxymethyl chitosan (N, O-CMCS) via biodegradable dynamic Schiff base linkages. The formation of the N, O-CMCS/OTG hydrogel was achieved under physiological conditions by optimizing the OTG to N, O-CMCS ratio. The presence of aldehyde and imine groups within the hydrogel structure confirmed using FTIR and NMR. Among the tested formulations, the N, O-CMCS/50OTG hydrogel exhibited a moderate gelation time of 3 min, along with the highest swelling (248%) and degradation (98%) ratios. Also, the N, O-CMCS/50OTG hydrogel demonstrated strong antibacterial activity against both S. aureus (60% reduction) and E. coli (52% reduction). Biocompatibility studies using L929 cell lines revealed approximately 95% cell viability. Additionally, a nearly complete wound contraction was achieved in a scratch assay after 7 days of exposure. The hemolytic assay confirmed the hemocompatibility of the hydrogels, as well. This hydrogel also promoted the expression of TGF-β1 and collagen type1 genes, which are active in the early phase of wound healing. Also, the ROS assay results in the hydrogel were highly promising. This novel injectable, self-healing, antibacterial hydrogel from polysaccharide derivatives, highlighting its significant potential for applications in wound dressing.