Localized electrical stimulation to C2C12 myotubes cultured on a porous membrane-based substrate

We report a porous membrane-based cell culture device that can conduct localized electrical stimulation of a cell monolayer. The device's cell culture substrate is a microporous alumina membrane with an underlying thin poly(dimethylsiloxane) (PDMS) film spotted with holes. When electric current is generated between the device's Pt ring electrodes-one of which is placed above the cells and the other below the PDMS layer-the current density condenses at the holes in the PDMS film, and cells located above the holes can be electrically stimulated. C2C12 cells were confluently cultured on the substrate and were differentiated to myotubes. To control the stimulated area in the substrate, we attempted to seal and reopen the holes of the PDMS film by using an air bubble. Since the current pulse could be effectively blocked at the sealed holes, fluorescent Ca²⁺ transients, indicative of cellular excitation, were observed from the myotubes located above holes in the open state.