Biocompatible κ-carrageenan/PVA/ZnO nanocomposite films for moisture regulation and antioxidant wound healing

The development of multifunctional wound dressings that integrate structural integrity, biocompatibility, and therapeutic efficacy remains a major challenge in biomedical applications. In current study, we fabricated bioactive nanocomposite films composed of Kappa-carrageenan (κc), polyvinyl alcohol (PVA), and zinc oxide nanoparticles (ZnO NPs) via a solvent casting technique. ZnO NPs (1-2 wt%) were introduced as multifunctional nanofillers to enhance mechanical, antioxidant, and barrier properties, while PVA served to improve the mechanical flexibility of the κc-based matrix. The films were comprehensively characterised in terms of chemical structure, morphology, mechanical and optical properties, surface wettability, water vapor permeability, bioactivity, and cytocompatibility. Fourier transform infrared spectroscopy revealed the formation of hydrogen bonding between κc and PVA, along with interfacial interactions with ZnO NPs, contributing to improved structural stability and enhanced functional performance. Among all formulations, the 1% ZnO film showed the highest mechanical strength of 40.2 MPa with moderate elongation at break of 81.9%, while the 2% ZnO film exhibited superior surface hydrophobicity (water contact angle: 108.1°) and the lowest water vapor permeability at 2.4 × 10^-8 g·m/(m²·s·Pa). Additionally, the incorporation of ZnO NPs significantly enhanced the UV-blocking capacity and DPPH radical scavenging activity. In vitro cytotoxicity assays using L929 fibroblasts further confirmed excellent biocompatibility, with cell viability exceeding 90% across all time points for ZnO loadings below 2 wt%. These findings highlight the crucial role of ZnO in enhancing the structure and performance of κc/PVA blends, supporting their potential as advanced wound dressing materials.