水力井應用於非接觸式單細胞抓取之微流體元件特性研究

對於量測不同細胞的反應，單細胞抓取扮演著相當重要的角色。本篇論文的目的為提供一個可以被利用於單細胞抓取與其相關研究的非接觸式微流體平台，並對此平台與其流場做一系列力學特性的研究。此平台利用了羅倫茲力驅動一平板做垂直於軸向的往復式運動並產生一區域性低壓區（或稱其為水力井）。利用此區域性低壓區將細胞抓在平板邊緣上方。細胞因流場中非線性的流動所產生的低壓區而懸浮並固定在空間中以抵擋背景流速。而元件的製作則是利用傳統的微影與軟微影製程。直徑五微米到六十微米大小的聚苯乙烯微粒子被用來測試不同大小範圍低壓區的箝制效果。懸浮型的Jurkat細胞則被利用來測試水力井對於細胞的選擇性與其可分離不同尺寸細胞的能力。藉由商用流場模擬軟體的幫助得以描繪出振動平台對於流場流速的變化以及流場中壓力分佈的變化。結果顯示只需峰間值在三到五伏特的驅動電壓即可達到箝制力的大小在22~96pN的範圍。由因次分析與模擬的結果可知振動平板的振幅為產生較大壓力變化之低壓區的一關鍵參數。本平台可利用適當的條件下可抓取不同大小尺寸細胞。此微流平台提供了單細胞分析一種強而有力箝制單細胞或是多個獨立單細胞的方法。

關鍵字

單細胞抓取；細胞操控；水力井；因次分析

並列摘要

Single cell trapping for measuring different cellular response is important for a variety of applications including rare cell studies, minimal residual disease, and improved understanding of basic cell biology. The purpose of this thesis is to provide an integrated noninvasive microfluidic platform which can trap single cells for subsequent studies. The proposed platform utilizes Lorentz force to drive an oscillating microplate generating localized low pressure region, or a hydrodynamic well, in order to trap single cells along the edge of the microplate. Cells are levitated by a time-mean low pressure due to nonlinear flow streaming, fixing cells in a spatial region against background flow. Fabrication of the device involved conventional photolithographic soft lithographic processes, with two masks for the microstructure and one for the microchannel. Different sizes of polystyrene particles were used to verify the wide range of single cell trapping feasible. Jurkat cells in suspended state were used to test the selectivity of hydrodynamic well and the ability to sort different size. Dimensional analysis was used to characterize the physics of the flow filed by commercial simulation software (COMSOL Multiphysics®). Results show the trapping force is in the range of dozens of pico-Newton with only 3 to 5 Vpp of driving voltage. Ability to select different size of cell shows the capability to trap different cell sizes with proper conditions. This microfluidic device provides a robust approach to trap single cells or multiple isolated cells effectively for cellular analysis.

並列關鍵字

single-cell trapping ； noninvasive ； cell manipulation ； hydrodynamic force ； dimensionless analysis

參考文獻

1. Di Carlo, D. and L.P. Lee, Dynamic single-cell analysis for quantitative biology. Analytical Chemistry, 2006. 78(23): p. 7918-7925.

2. Harwood, M.M., J.V. Bleecker, P.S. Rabinovitch, and N.J. Dovichi, Cell cycle-dependent characterization of single MCF-7 breast cancer cells by 2-D CE. Electrophoresis, 2007. 28(6): p. 932-937.

3. Neher, E. and B. Sakmann, SINGLE-CHANNEL CURRENTS RECORDED FROM MEMBRANE OF DENERVATED FROG MUSCLE-FIBERS. Nature, 1976. 260(5554): p. 799-802.

4. Tan, S.C.W., W.X. Pan, G. Ma, N. Cai, K.W. Leong, and K. Liao, Viscoelastic behaviour of human mesenchymal stem cells. Bmc Cell Biology, 2008. 9: p. 7.

5. Seo, J., C. Ionescu-Zanetti, J. Diamond, R. Lal, and L.P. Lee, Integrated multiple patch-clamp array chip via lateral cell trapping junctions. Applied Physics Letters, 2004. 84(11): p. 1973-1975.

國際替代計量

水力井應用於非接觸式單細胞抓取之微流體元件特性研究

全文下載

主題瀏覽