Polyurethane nanocomposite impregnated with chitosan-modified graphene oxide as a potential antibacterial wound dressing

Abstract

In this study, a polyurethane nanocomposite film (PU/CS-GO) was synthesized by incorporating chitosan-modified GO nanosheets (CS-GO) into PU matrices. The successful synthesis of unmodified GO and CS-GO nanosheets was confirmed by FTIR, XRD, Raman, SEM, EDS, and TGA analyses. In comparison with polyurethane nanocomposite containing unmodified graphene oxide (PU/GO), the effect of the modification of GO with chitosan on different properties such as morphological, thermal, thermo-mechanical, wettability, antibacterial, and biocompatibility properties was evaluated by various analyses including XRD, FE-SEM, TGA, DMTA, contact angle, antibacterial studies, and MTT assay. FE-SEM images exhibited better dispersion of CS-GO nanosheets within polyurethane matrices compared to GO nanosheets. According to DMTA results, PU/CS-GO showed a higher glass transition temperature (Tg) and storage modulus values than PU/GO sample. Based on antibacterial and MTT assays, in comparison with PU/GO, the PU/CS-GO nanocomposite demonstrated better biocompatibility and also antibacterial activity against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. Based on results, the PU/CS-GO nanocomposite can be suggested as a promising material for antibacterial wound dressing.

Keywords: Chitosan; Graphene oxide; Nanocomposite; Polyurethane elastomer; Surface modification; Wound dressing.