OPTIMIZATION OF CROSS-LINKED PVA FUNCTIONALIZED WITH PANI: IN SITU STRATEGIES TO DESIGN ELECTRO-CONDUCTIVE FIBROUS PLATFORMS FOR BRAIN APPLICATIONS

Polyelectrolyte hydrogels such as polyvinyl alcohol (PVA) can be combined with conductive polymers to create bioactive and electrically responsive materials for biomedical use. In this study, we prepared PVA hydrogel in the form of electrospun nanofibrous mats containing two different forms of polyaniline (PANI)—emeraldine base (EB-PANI) and PANI nano short fibers (PANI-NF)—and evaluated their morphology, electrical behavior, and biological response. Citric acid was used as a crosslinker to improve the water stability and structural integrity of the electrospun mats.

Electrospinning was carried out using PVA/PANI blends, followed by a short thermal treatment to activate crosslinking. The obtained fibers were analyzed by SEM, which showed uniform morphologies. Pure PVA fibers had an average diameter of about 0.53 µm, while the addition of PANI slightly increased the fiber size (0.65 µm for EB-PANI and 0.72 µm for PANI-NF). Electrical tests indicated conductivity values between 10⁻8 and 10⁻⁷ S/cm. Non-crosslinked samples showed generally higher conductivity, while crosslinking affected EB-PANI and PANI-NF differently: EB-PANI maintained stable values, whereas PANI-NF displayed reduced conductivity, probably linked to their different protonation and charge transport mechanisms. In vitro experiments with SH-SY5Y neuroblastoma cells confirmed that all scaffolds were cytocompatible and supported cell adhesion and proliferation up to 14 days, with no signs of toxicity.

These results show that PVA/PANI hydrogel-based nanofibers can be considered as conductive and biocompatible scaffolds, suitable for applications in the brain field. The comparison between EB-PANI and PANI-NF highlights the role of PANI structure on conductivity and provides useful information for optimizing electro conductive platforms.