Bioactive wound dressings based on polymer nanofibers fabricated by electrospinning

Advances in wound dressings relies on the development of novel materials that are able to revolutionize traditional approaches, offering more effective and personalized wound care. Electrospun nanofibers have been widely used recently as wound-healing dressings. Nanofibers have high porosity and good biocompatibility, promoting cellular respiration and regeneration of damaged skin. In addition, nanofibers can encapsulate active substances, such as hyaluronic acid (HA), which accelerates the healing process by regulating inflammatory responses, improving angiogenesis and collagen deposition at the wound site, and reducing scar formation. Here, we investigate the fabrication of HA-containing polyvinyl alcohol (PVA) nanofibers using the electrospinning technique. To enhance the stability of the PVA/HA nanofibers in aqueous environment, and avoid fast dissolution during wound healing, crosslinking by citric acid (CA) is studied. Polymer solutions for electrospinning were prepared by dissolving PVA, HA and CA in ultrapure water in appropriate ratios. The process parameters were optimized in terms of applied voltage, flow rate, collecting distance and needle size. The obtained nanofibers were heat-treated at 150 °C to activate crosslinking by CA. FTIR was used to characterize the chemical composition and crosslinking of the samples. Morphology of the nanofiber mats was investigated by SEM, and thermal analysis by DSC was used to determine melting temperatures. To evaluate the potential application of the PVA-modified nanofibers for wound dressings, swelling and degradation tests were performed in PBS solution with different pH values (7–9). PVA/HA/CA nanofibers were successfully prepared via solvent-free electrospinning. SEM analysis revealed that the fabricated fibers have diameters < 200 nm with a consistent size distribution across different samples. FTIR analysis confirmed crosslinking in the heat-treated PVA/HA/CA samples, and a decrease in melting temperature upon increase of the crosslinking time was determined by DSC. Swelling tests in PBS solution demonstrated that the heat-treated nanofibers are insoluble in water and that a correlation exists between the crosslinking time and the reduced dissolution of the samples. Finally, degradation tests in PBS confirmed the stability of the cross-linked nanofiber mats up to 48 h.