Electrically induced contraction of C2C12 myotubes cultured on a porous membrane-based substrate with muscle tissue-like stiffness

A porous membrane-based cell culture device was developed to electrically stimulate a confluent monolayer of C2C12 myotubes. The device's cell culture substrate is a microporous alumina membrane-modified by attaching an atelocollagen membrane on the upperside and a hole-spotted poly(dimethylsiloxane) (PDMS) film on the underside. 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 focused current at the PDMS hole can electrically stimulate the cells. C2C12 myoblasts were cultured on the substrate and differentiated into myotubes. When the electrical pulses were applied, myotubes started to contract slightly in and near the hole, and that the continuous stimulation increased both the number of stimuli-responding myotubes and the magnitude of the contraction considerably owing to the underlying atelocollagen membrane with muscle tissue-like stiffness. Also, the generation of contractile myotubes on a wider region of the membrane substrate was possible by applying the electrical pulses through the array of holes in the PDMS film. Using the present system, the glucose uptake by contractile myotubes was examined with fluorescence-labeled glucose, 2-NBDG, which displayed a positive correlation between the contractile activity of myotubes and the uptake of 2-NBDG.