Bio-Nano Platform for Cell-Cell Communication

We have developed a novel microfluidic device for space- and time-resolved  visualization of intracellular events when a cell surface is partially exposed to external stimuli. The device, fabricated using 3D rotational inclined UV lithography of photoresist SU-8, consists of a cell-containing chamber and a flow channel separated by a thin vertical wall having a lateral micrometer aperture smaller than a cell. A cell is first immobilized on the aperture by suction from the flow channel using a syringe pump, and a chemical stimulant is then fed to the channel so that only the cell surface bounded by the aperture is subjected to the stimulus without leakage to other part of the cell surface. The subsequent lateral signal propagation inside the cell can be visualized using high-speed fluorescence confocal microscopy. As an experimental demonstration of the device, 2-NBDG (fluorescence glucose analog) intake into a mouse insulinoma cell, MIN6m9, was visualized in 4D resolution.

And to measure the cell-cell communication of the MIN6m9, we developed the double layered micro fluidic channel with micro orifice to stimulate the target cell. The cell are immobilized on the micro orifice and the target cell is stimulated by the high glucose solution by the micro cannel which is designed only target cell is stimulated. The micro-channels and micro-orifices are simultaneously fabricated by using inclined UV lithography. And the cytosolic Ca2+ concentration of immobilized cells is measured.