F222001 細胞機能計測マイクロデバイスの研究開発

Abstract

In the field of re-generative medicine, understanding the function of cell and tissue is key issue. To understand the cell and tissue functions, many micro devices, called Micro TAS( Total analysis systems) are proposed and used in the field of medicine and life science research. We are studying the function of the pancreas islet. Pancreas islet is composed of mainly p cell and a cell,. The function of those cells are opposite. The (3 cell secrete the insulin to decrease the concentration of blood sure and a cell secrete the Glucagon to increase it. We have developed two types of novel microfluidic device for space- and time-resolved visualization of intracellular events when a cell surface is partially exposed to external stimuli. First device is horizontal type to measure the insulin secretion of p cell. And second device is vertical type to measure the cell -cell communication. Both devices, 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, see Fig.l. A cell is first immobilized on the orifice 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 first demonstration, see Fig.2, shows the fabricated orifice to immobilize the cell. As an experimental demonstration of the device, The subsequent lateral signal propagation inside the cell can be visualized using high-speed fluorescence confocal microscopy. 2-NBDG (fluorescence glucose analog) intake into a mouse insulinoma cell, MIN6m9, was visualized in 4D resolution. The structure of the second device to measure the cell- cell communication is shown in Fig.3. 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.