Fabrication of Sophora fructus loaded polyvinyl alcohol nanofibers for antibacterial wound dressings

Abstract Poly(vinyl alcohol) (PVA) nanofibers incorporating 20 wt% Sophorae fructus extract (SFE), which exhibits antioxidant and antibacterial activities, were fabricated by electrospinning and heat-treated at 160–180 °C for 30–60 min to induce physical cross-linking for wound dressing applications. The effects of heat treatment on fiber morphology, mechanical properties, porosity, water vapor transmission rate (WVTR), moisture retention, degradability, and bioactivity were systematically evaluated. Fiber diameter increased with increasing heat-treatment temperature and duration due to fiber fusion and heat-induced deformation at inter-fiber contact points. The initial modulus, tensile strength, and elongation at break generally increased after heat treatment, whereas porosity, absorbency, degradability, and antioxidant release decreased. In contrast, WVTR and antibacterial activity against Staphylococcus aureus were not significantly affected by heat treatment. Considering the physicochemical and biological requirements of wound dressings, the optimal heat-treatment condition for SFE/PVA nanofibers was identified to be 170 °C for 45 min. These results demonstrate that controlled heat treatment is an effective strategy for optimizing the performance of SFE/PVA nanofiber-based wound dressings.