Hydrogel-supported skeletal muscle cell-based bioassay system

Contractile C₂C₁₂ myotube line patterns supported by a fibrin gel have been developed to afford a physiologically relevant and stable bioassay system. Myotube line patterns cultured on dish were transferred with 100% efficiency to the surface of fibrin gel sheets. We found that the myotubes supported by an elastic fibrin gel maintained their line patterns and contractile activities for a longer period of time (one week) than myotubes adhered on a conventional culture dish. The gel sheet-supported C₂C₁₂ myotube micropatterns were combined with a microelectrode array chip to fabricate a skeletal muscle cell-based bioassay system. The contractile behavior of each myotube line pattern on the gel was individually controlled by localized electrical stimulation using microelectrode arrays that had been previously modified with the electropolymerized conducting polymer. We successfully demonstrated fluorescent imaging of the contraction-induced translocation of the glucose transporter, GLUT4, from intracellular vesicles to the plasma membrane of the myotubes. This device is applicable for the bioassay of contraction-induced metabolic alterations in a skeletal muscle cell.