Muscle cells and tissue photostimulation.

Nowadays living cells stimulation is an emerging and hot topic. In particular, contactless and wireless methods are extremely appealing due to a reduced alteration of the analyzed biological systems. Light is an ideal tool to satisfy these requirements and achieve high spatio-temporal resolution. Conjugated molecules and macromolecules, characterized by chemical synthesis' easiness and relatively low toxicity, have proven their efficacy at the interface with living cells when used as phototransducers. Excitable cells are interesting candidates to test the material-based photostimulation. Indeed, muscle cells are a fascinating target due to their contraction ability and electrical properties. Photostimulation can be even more appealing in muscular tissue pacing where the highly organized structure must be preserved for an efficient contraction. In this work, we used an azobenzene compound to control muscular cells and tissue. We characterized the cells-phototransducers interaction evaluating cell's electrophysiology, calcium wave and contraction activity. Finally, the proposed photostimulation was used on $in vitro$ micro-physiological system.