Cross-Linked PVA Nanofibers Functionalized with PANI via In Situ Strategies to Develop Electroconductive Interfaces for Brain Applications

Current approaches in neuro-technologies aim to design artificial devices capable of collecting information on in vitro and in vivo brain activities. In this view, a major challenge for new processing technologies is to integrate the peculiar properties of biomaterials and electrical circuits into engineered devices. Herein, the optimization of electroconductive polyvinyl alcohol (PVA) fibers loaded with polyanilines (PANIs) and produced via electrospinning is proposed. Two different polyaniline forms were selected, i.e., doped emeraldine base (dPANI-EB) and doped PANI nanofibers (dPANI-NFs) synthesized by a rapid mixing process. SEM morphological investigation indicated that conductive phases do not remarkably affect fiber morphology, slightly increasing the average diameter. Conversely, PANI fibers remarkably affect the PVA surface’s hydrophilicity, as confirmed by the increase in contact angle. The presence of conductive phases enhances the intrinsic ionic conductivity of PVA fibers, through protonic currents, which also increases the electronic conductivity from 10−10 to 10−7 S/cm. Preliminary in vitro studies performed on a human neuroblastoma cell line (SH-SY5Y) confirmed the biocompatibility of PVA/PANI nanofibers. These data demonstrate the potential of such nanofibers to be used as biotextiles, and specifically as electroactive interfaces capable of monitoring changes in the levels of biochemical signals (i.e., neurotransmitters) related to the brain’s microenvironment.