Best oral presentation - Annual Meeting of the Italian Society for Biomaterials

Introduction In this study, the fabrication of bioactive nanofiber (NF) dressings based on polyvinyl alcohol (PVA) and hyaluronic acid (HA) prepared by electrospinning technique was investigated to improve wound healing. However, the high solubility of NFs in an aqueous environment limits their use in biological environments, so this study proposes to develop chemically crosslinked NFs of PVA/HA by solid-state esterification without catalyst through thermal treatment at 150 °C using citric acid (CA) as a bio-based crosslinking agent Experimental methods To produce NFs, polymer solutions containing PVA, HA, and CA were prepared by dissolving the polymers in ultrapure water in specific proportions. The electrospinning process parameters were optimized. The resulting NFs were thermally treated at 150 °C to activate crosslinking by CA. Results and discussion Chemical crosslinking by thermal treatments highlights a simpler and safer method of achieving nanofiber stability. SEM analysis revealed that the fabricated fibers have diameters below 200 nm with a consistent size distribution across different samples. FTIR analysis confirmed the chemical crosslinking of the nanofibers by the esterification process, and DSC analysis evaluated the thermal behavior of the NFs and demonstrated their stability in the physiological range. Swelling tests in PBS solution demonstrated that the thermal-treated nanofibers are insoluble in water and a correlation between the crosslinking time and the reduced dissolution of the samples. Conclusion Nanofibers based on PVA and hyaluronic acid crosslinked with citric acid were successfully produced by electrospinning without the use of organic solvents. Degradation tests in PBS confirmed the stability of the crosslinked nanofiber mats up to 48 h making them good candidates for bioactive healing applications.