Nanocellulose-lignin films incorporating AgNPs for potential wound dressing: green synthesis, antioxidant ability, antibacterial capability and biocompatibility

Developing wound dressings from natural bioresources with high antibacterial properties and low drug resistance is highly desirable. In this study, bio-based films incorporated with Ag nanoparticles (AgNPs) were fabricated via a green and facile route. Firstly, AgNPs were obtained by reduction of AgNO 3 with lignin nanoparticles (LNPs). Then the dialdehyde cellulose nanofibers (DACNFs) were prepared by periodate oxidation of cellulose nanofibrils, and mixed with LNP-Ag to fabricate composite films (DACNF-LNP-Ag). It was found that the higher the concentration of AgNO 3 , the smaller size and larger quantities of AgNPs. The incorporation of LNP-Ag endowed the composite films with high UV blocking and antioxidant properties. The tensile strength of the composite film with 2% LNP-Ag increased significantly from 44.5 MPa to 62.6 MPa. After 1-h immersion in water, the wet tensile strength of the composite films decreased to 18.5–27.5 MPa, but much higher than that of wet CNF film. The incorporation of LNP-Ag resulted in a decrease in water adsorption of the composite films while exhibiting insignificant influence on water contact angle (WCA) and water transmission rate (WVTR). The survival rate of L929 cells was more than 90% after been co-cultured with leachate of the composite films for 24 h, indicating their good biocompatibility. The composite films demonstrated high BSA adsorption and antibacterial activities against E. coli and S. aureus . These advantages of the composite films exhibit promising potential as the wound dressing. Graphical Abstract