Development of biocompatible and antibacterial chitosan polyethylene oxide nanocomposite films reinforced with zinc oxide graphene oxide for wound dressing applications

This study reports the fabrication and characterization of chitosan (Cs)/polyethylene oxide (PEO) nanocomposite films containing 0, 0.2, 0.4, and 0.8 wt% zinc oxide nanorods/graphene oxide (ZnO/GO) hybrid nanofillers for potential wound dressing applications. The structural, optical, dielectric, electrical, mechanical, biocompatibility, and antibacterial properties of the films were systematically investigated. XRD and FTIR analyses confirmed the incorporation of ZnO/GO and revealed changes in the structural organization and intermolecular interactions of the Cs/PEO matrix. The optical band gap decreased progressively with increasing ZnO/GO content, from 4.43 to 2.14 eV for the indirect transition and from 4.89 to 3.81 eV for the direct transition. At 0.1 Hz, the dielectric constant increased from 529 for pristine Cs/PEO to 46,680 for the 0.8 wt% ZnO/GO composite, while the conductivity at 40 Hz increased from 6.12 × 10⁻¹³ to 3.18 × 10⁻⁷ S/cm. The tensile strength increased from 29 MPa for pristine Cs/PEO to 35 MPa at 0.8 wt% ZnO/GO, while the 0.4 wt% composite provided a favorable balance between tensile strength (33 MPa) and elongation at break (102%). In vitro cytocompatibility was enhanced, with cell viability increasing from 82.11 ± 3.2% for pristine Cs/PEO to 95.62 ± 2.3% at 0.8 wt% ZnO/GO. Antibacterial activity also increased progressively with ZnO/GO loading, with inhibition zones reaching approximately 11.4 mm against Escherichia coli and 12.2 mm against Staphylococcus aureus at 0.8 wt%. Overall, 0.8 wt% ZnO/GO provided the most pronounced optical, dielectric/electrical, cytocompatibility, and antibacterial responses, whereas 0.4 wt% offered a favorable balance of mechanical strength and flexibility. These findings demonstrate the potential of Cs/PEO-ZnO/GO nanocomposite films as multifunctional materials for antibacterial wound dressing applications.