Study on dielectrophoretic separation/focus and thermal therapy of carcinoma cells

• Main Authors: Ching-Te Huang, 黃景德
• Other Authors: Chun-Ping Jen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/41032306228466958498

博士 === 國立中正大學 === 機械工程所 === 98 === When microfluidic chip applies in cancer detection, cell sorter and cell counter, the manipulation cell is the first thing for the other application. In recent research, focusing of biological cells often utilize complicated microchannel and structure to manipulate cells. The unnecessary materials must be separated from tested solution. Therefore, those method need to combine with cells separation and precise flow control. The main purpose of the present study is to design an insulator-based dielectrophoretic microdevice for effective separation and focusing of biological cells simultaneously without precise flow control. Four insulating structures which formed an X-pattern in the microchannel are employed to squeeze the electric field in a conducting solution, thereby generating the non-uniform electrical field. The gap of between two insulating structures will generate high electric-field. When cells are induced positive dielectrophoretic forces in non-uniform electrical field, the cells are trapped by high electric-field. The cells repelled toward the center of the microchannel, when negative dielectrophoretic forces are induced. The increase of the X-pattern structure is significantly to enhance the performance of focusing. The device proposed herein has successfully separate unnecessary materials and focus the biological cells. Experimental results indicate that the performance of focusing increases with the strength of the electric field applied or with a decrease in the inlet velocity and that results are agree with the predictions by numerical simulations. The surgery, radiotherapy, chemotherapy and multiple therapies are the main treatment in recent years. However, those treatments are hurtful for health. Thermotherapy (hyperthermia) is a method for treatment carcinoma cells. Mechanism of malignant tumor thermotherapy has been an important issue for human. The cellular proteins and organelles are suffer from structural alternations and irreversible denaturation duration of exposure to supraphysiological temperatures, which may induce cell death. Besides, most of researches for thermotherapy of cancer have been reported based on the biological levels of organ or tissue. The thermotolerance of two hepatocellular carcinoma cell lines, HepG2 and Hep3B (well-differentiated), and three human urinary bladder carcinoma cell lines, TSGH-8301, J82 and TCC-SUP (cytological grade 2, 3 and 4, respectively), are investigated in the present study. A home-made heating stage is used to provide a constant temperature for 40 to 70°C. The experimental data show that the HepG2 exhibit higher thermotolerances then Hep3B. Besides, the TCC-SUP and TSGH-8301 cells exhibit the lowest and highest thermotolerances, respectively, while J82 cells are intermediate. The results indicate that the high cytological grade of the cell line of bladder cancer exhibits a low thermotolerance. Heat shock proteins play an important role in protecting cells from heat stresses. In some literatures indicate that the heat shock proteins have connect with differentiated. The experimental results of thermotherapy are coincident with the literatures. Moreover, the cell membranes of these cells are damaged and ruptured duration thermal treatment.