Résumé : Injectable hydrogels, which are polymeric materials that are characterized by their ability to be injected in a liquid form into cavities and subsequently undergo in situ solidification, have garnered significant attention. These materials are extensively used in a range of biomedical applications. This study synthesized several injectable composite hydrogels through the mild Schiff base reaction while imposing different concentrations of quaternary ammonium chitosan and oxidized pullulan. Subsequent characterizations revealed a consistent and coherent porous structure within the hydrogels with smooth inner walls. The hydrogels were also determined to possess good adhesion, mechanical properties, self-healing ability, and injectability. Furthermore, antimicrobial tests against Escherichia coli and Staphylococcus aureus demonstrated antibacterial properties, which improved with increasing concentrations of quaternary ammonium chitosan. Co-culturing with skin fibroblasts demonstrated that the injectable hydrogels exhibited favourable biocompatibility and the capacity to boost cellular activity, thus underscoring its potential for use in biomedical applications.