In this research, natural and biocompatible polymers, namely chitosan and sodium alginate, were modified to create a self-healing and injectable nanocomposite hydrogel to be used as a wound dressing. At first, the surface modification and characterization of chitosan and sodium alginate were carried out to produce carboxyethyl chitosan (CECH) using acrylic acid, and oxidized sodium alginate (OSA) using sodium periodate. respectively. Subsequently, to enhance the mechanical properties and self-healing capability of the hydrogel, cellulose nanofibers were incorporated at various weight percentages. Additionally, to improve antibacterial properties, copper oxide nanoparticles were added at different concentrations to the hydrogel. These measures led to a significant increase in the hydrogel's swelling capacity, reaching approximately 3000%, which is of great importance for its application as a wound dressing material. Furthermore, the introduction of copper oxide nanoparticles and cellulose nanofibers contributed to the hydrogel's reduced degradation compared to hydrogels without nanomaterials, resulting in enhanced stability over an extended period. Mechanical testing demonstrated an increased compressive modulus in the nanocomposite hydrogel. Moreover, the hydrogel exhibited self-healing capabilities within 30 minutes and was injectable at the application site. The antibacterial properties of the hydrogels were eva‎luated, with the copper oxide-containing hydrogel demonstrating effective antibacterial activity against Staphylococcus aureus and Escherichia coli bacteria. Importantly, none of the hydrogel samples displayed cellular toxicity, and the hydrogel containing 0.105% cellulose nanofibers and 0.032% copper oxide nanoparticles exhibited the highest absorption capacity (109.932%). Based on these findings, the injectable carboxyethyl chitosan/oxidized sodium alginate/cellulose nanofiber/copper oxide nanoparticle nanocomposite hydrogel is proposed as a suitable option for use in skin wound dressings. It fulfills the necessary criteria for wound dressings and is presented as a promising choice for this application in comparison to other research in the field.

سعيد نوري خراساني , رسول اسمعيلي نيسياني

منيره كوهي , شهلا خليلي

افسانه فخار , محمد ديناري