Giuseppina Polino1 Angela Langella1 Valentina Mollo1 Aldo Di Carlo2 Francesca Brunetti2 Paolo Netti1 Francesca Santoro1

1, Istituto Italiano di Tecnologia, Naples, , Italy
2, Università di Roma Tor Vergata, Rome, , Italy

Conducting polymers (CP), such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), are widely used to interface electronics with biology due to their mechanical, physical-chemical properties similar to biological tissue [1, 2]. In particular, CP electrodes present low impedance when interfaced to excitable tissues and it was demonstrated an improved adaptability to the brain tissue and an increased charge-transfer efficiency. In this work, we investigated the possibility to employ PEDOT: PSS modified with different amount of poly-ethylene glycol dyacrilate (PEG DA) to evaluate the effect on the conductivity of PEDOT PH1000 to realize efficient electrodes for organic photovoltaic solar cells for light-induced electrical field for cell inhibition/stimulation. PEG DA is an easily modifiable polymer that is widely used in hydrogel fabrication, including 2D and 3D scaffolds for tissue culture [3]. Here, we present a comparison between different PEDOT:PSS with and without PEG DA deposited by spin and spray - coating techniques in order to obtain different surface morphologies. The functionality and electrochemical behavior of electrodes and the morphology of the film was evaluated using electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). To investigate the biocompatibility of modified PEDOT: PSS in terms of cells vitality and to discriminate optimal cell adhesion conditions when different morphologies of polymeric film are considered, we performed a toxicity assay based on viability of U87-MG astrocyte like cells (human glioblastoma cell lines). Finally, we reported the adhesion and biocompatibility of the cells seeded on PEDOT [4], in order to produce 3D organic photovoltaic devices for light inhibition of U87 cells to reduce tumoral cells proliferation rate [5].

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