Microfluidic Device for Monitoring and Evaluation of Intracellular Mechanostress Responses

摘要

This paper presents a microfluidic device for monitoring and evaluating real-time cellular responses to compression stimuli. The device was produced by a three-dimensional micro structure fabrication process using multiple exposures to the photoresist. The presented device consists of cell inlet ports, a pressure inlet port, a gasket, microchannels, culture chambers, and a diaphragm on the culture chamber for applying compressive pressure to cells. Compression stimuli applied to the cells can be controlled by regulating the expansion of the diaphragm via a pressure control. The device permits the observation of cellular responses to compressive pressure in real time because it is made of transparent materials and stimulates the cells without deforming the cell culture surface, when observed by optical microscope. We observed the cellular deformation and response behavior using a fabricated microdevice in real time. The changes of intracellular calcium concentration before and after compressive stimuli were observed by the fabricated device. Also, the intracellular maximum strain part and strain distribution of a cell that received compression stimulus were clarified by FEM analysis. Moreover, threshold level of cell deformation amount and strain amount which a cell detects was evaluated by combination of the cell compression test and FEM analysis. These results indicate the device is expected to clarify the cellular mechanoreceptor mechanisms and signal transduction pathways and facilitate the control of stem cell differentiation by a combination of the experimental results and FEM analysis results.