Monitoring of Orientation of Cells by Electric Impedance: Test on Oriented Cells Using Micro Striped Grooves Pattern by Photolithography

The electric impedance has been measured to estimate the orientation of cells in vitro. To arrange the orientation, several parallel lines of micro rectangular grooves (1 µm depth, 3 µm width and interval) have been made between a pair of the surface titanium electrodes on the scaffold of glass by the photolithography technique. Two types of arrangements of lines were designed related to the micro grooves: parallel, and perpendicular to the electric line of force between electrodes. C2C12 (mouse myoblast cell line) was cultured on the micro-patterned scaffold. The electric impedance (Z) between electrodes was measured every 24 hours with the sinusoidal electric waves (frequency, 1 kHz < f < 10 MHz; amplitude, v = ± 0.05 V) for three days. The number of oriented cells (Ns) was defined by the number of cells, which cross the straight-line bands of 0.01 mm width connecting between electrodes. The experimental result shows that Z increases with Ns. The phase difference between the voltage and the current is larger at the arrangement of myoblasts oriented in the perpendicular position than that in the parallel position. The present study shows that the measurement of the electric impedance is effective to estimate the orientation of cells.