Bipolar electroactive conducting polymers for wireless cell stimulation

Conventional organic conducting polymers (CPs)-based electrical stimulation (ES) systems have been extensively explored in modulation of cell and tissue functions for biomedical applications. Bipolar electrochemistry could offer an effective pathway to modify these ES systems into a more desirable contactless mode. In this study, we present for the first time the development of a CP-based bipolar electrostimulation (BPES) system for living cells. Polypyrrole (PPy) films with different dopants have been utilised to demonstrate reversible and recoverable bipolar electrochemical activity under a low driving DC voltage (<5.5 V). A BPES prototype enabling wireless and programmable cell stimulation has been devised using PPy co-doped with dextran sulfate (DS) and collagen (PPy-DS/collagen) as a bipolar electrode and rat pheochromocytoma cells as a model cell line. Significantly, wireless stimulation enhances cell proliferation and differentiation. The work establishes a new paradigm for the electrostimulation of living cells using CPs as the bipolar electrodes, which provides an attractive wireless approach to advance the field of medical bionics. (C) 2020 Elsevier Ltd. All rights reserved.