E-beam crosslinked, biocompatible functional hydrogels incorporating polyaniline nanoparticles

PANI aqueous nanocolloids in their acid-doped, inherently conductive form were synthesised by meansof suitable water soluble polymers used as stabilisers. In particular, poly(vinylalcohol)(PVA) or chitosan (CT) was used to stabilise PANI nanoparticles, thus preventing PANI precipitation during synthesis and upon storage. Subsequently,e-beam irradiation of the PANI dispersions has been performed with a 12 MeV Linac accelerator. PVA-PANI nanocolloid has been transformed into a PVA- PANI hydrogel nanocomposite by radiation induced crosslinking of PVA.CT-PANI nanoparticles dispersion, inturn,was added to PVA to obtain wall-to-wall gels, as chitosan mainly under goes chain scission under the chosen irradiation conditions. While the obtain ment of uniform PANI particle size distribution was preliminarily ascertained with laser light scattering and TEM microscopy,the typical porous structure of PVA-based freezedried hydrogels was observed with SEM microscopy for the hydrogel nanocomposites. UV-visible absorption spectroscopy demonstrates that the characteristic, pH-dependent and reversible optical absorption properties of PANI are conferred to the otherwise optically transparent PVA hydrogels.Selected formulations have been also subjected to MTT assays to prove the absence of cytotoxicity