Schiff base formed functional hydrogel dressing via ε-poly-L-lysine modified chitosan and oxidized dextran with the incorporation of epigallocatechin-3-gallate

Hydrogel-based functional dressings for wound healing have garnered increasing attention due to their excellent hydrophilicity, adjustable mechanical properties, and superior biocompatibility. In this study, a composite hydrogel was facilely fabricated through the Schiff base reaction betweenϵ-poly-L-lysine modified chitosan (CS-PL) and oxidized dextran (Odex). The formed hydrogel displayed the interconnected microstructure (100-200 μm), injectability, and adjustable mechanical properties. Macroscopic observation and alternating strain rheological analysis confirmed the good self-healing ability of the hydrogel. Furthermore, with the incorporation of epigallocatechin-3-gallate, the composite hydrogel exhibited an improved reactive oxygen species (ROS) scavenging capability and good antibacterial activity againstE. coliandS. aureus. The designed composite hydrogel dressings exhibited hemolysis rates of 0.75 ± 0.60% to 0.81 ± 0.31%, indicating their excellent hemocompatibility. Moreover, CCK-8 analysis and fluorescent images confirmed the excellent cytocompatibility of the hydrogels after co-culturing with NIH 3T3 cells for various periods. The above results offer a promising strategy for preparing functional hydrogel dressings viaϵ-PL modification on CS for wound healing applications.