Photoactive organic substrates for cell stimulation : progress and perspectives

Modulating the cell membrane potential provides an opportunity to control electrical signaling that is central to cellular physiology and its proper biological function. Among the many technological tools available to enable this modulation, optical stimulation through a photoactive substrate is a powerful strategy that is minimally invasive and wireless. This is critical to avoid disrupting the structural integrity of the cell membrane that is often caused by the use of electrical stimulation electrodes or changing its genetic footprints if optogenetics is the approach taken to photomodulate its electrophysiology. The use of a photoactive substrate such as an organic semiconductor combines optoelectronic properties with mechanical tissue compatibility, which is unachievable with inorganic semiconductors. This research news first discusses the mechanisms of cell photostimulation via these organic photoactive substrates and techniques employed to characterize their photoresponse. Then a summary of the relevant organic materials and their recent applications in cellular photostimulation is presented. Finally, the challenges in the field are described and a perspective on how to address these is provided.