| Currently, we are heading towards the period of nanotechnology which extends to many engineering disciplines. The necessity of its development is crucial to make life more convenient, to improve efficiency of each research field, and to integrate portable point-of-care system. Thus, the next most important step is to develop a technology to meet the needs of both industry and research area.;The main objective of the project was to apply the use of technology including microfluidic devices and cells-on-chip for cellular functional studies. First of all, the multilayered microfluidic device was used for the size-based separation of a heterogeneous mixture of particles at multiple scales. To verify the ability of the device composed of constriction channels of differing heights which were capable of the size-based separation, heterogeneous populations of particles of varying size between 1 and 300 microm were prepared, and the height of constriction channels varied from 0.5 microm to 290 microm. The devices were fabricated by using the methods of soft-lithography and molding micro-patterned PDMS plates. In addition, for the application of the device to biological samples, cultured bacteria, environmental sample, and mouse islets were analyzed in the multilayered microfluidic device by turns. The heterogeneous populations of microparticles including cells were successfully separated into several sub-populations with high homogeneity of each subpopulation and trapping efficiency.;Furthermore, the integrated microfluidic multiperfusion device was created for the dynamic islet culture used for multiple drug toxicity tests. To achieve the purpose, the device composed of the three layers contained a comb-patterned micromixer, cell and media distributor, perfusion chambers that encompass the array of 91 microwells that help immobilize the islets when exposed to flow, and microfluidic channels for the manipulation of drugs, cells, and media. In addition, the inner wall of microchannels was sol-gel treated for decrease in drug absorption to the wall and increase in biocompatibility. The perfect mixing of two fluids of different concentrations, even distribution of particles based on size and number, fast diffusion of the drugs, and various glucose gradients in the perfusion chambers were achieved in this device for dynamic drug toxicity tests. |
