近年來，個人化癌症醫療蓬勃發展。為此，如何將腫瘤細胞從臨床檢體中快速且精確的分離出來對臨床診斷與檢測是非常重要的，然而目前傳統的腫瘤分離方法各有缺點，例如純度低或是操作過程繁瑣耗時等。而免標定、靈敏與可攜式之微型化生醫晶片於近年來已成為來極受矚目的研究方向，其中更以微流體與電動力學技術為基礎者，被認為最適合於發展成微型化分離裝置。因此，本研究想利用旅波式介電泳設計之微流道中來對臨床檢體中的腫瘤細胞進行連續式的分離。本研究以癌症致死第一名的肺癌為研究模式，首先利用介電泳原理探討血液樣本以及肺癌細胞株介電特性，接著再以肺癌胸腔積液臨床樣本進行評估，最後利用此特性設計微系統分離晶片進行細胞分離。而此分離晶片主要設計旅波式介電泳場垂直於連續流場，而達有效增加旅波介電泳場的作用時間，進而加速分離的速度，可成功將胸腔積液中的腫瘤細胞與免疫細胞分離至其特定的子流道，分離純度可達將近95%以上，回收率亦達85%以上，而臨床樣本中以流式細胞儀所無法處理的細胞團塊，亦可成功的被分選。我們期許未來此微型化分離裝置之開發將可應用在臨床上，幫助現今個人化癌症醫療達到快速分離檢測之效果。

Recently, personalized cancer treatment has been developed vigorously. For this reason, separation of tumor cells from clinical samples is very important for biomedical applications. There are some drawbacks in the current methods for tumor cell separation. In addition to being time-consuming, these methods usually require complicated operations and the resulting tumor cell samples often have low purity. A label-free, sensitive, portable bioassay kit is a demanding research goal for clinical diagnosis. Microfluidics and electrokinetics are the key techniques that are very suitable for the development of a miniaturized device. Based on this, we would like to utilize traveling wave dielectrophoresis (twDEP) theory to design a microfluidic separation chip for sorting the malignant pleural effusions. In our research, we first characterized cultured cancer cells in vitro and blood cells using DEP analysis and found that the DEP patterns are dramatically different. Similar results were found in malignant pleural effusions (MPE) derived cancer cells and immune cells. Cells sort based on traveling wave dielectrophoresis that provides the lateral displacements of specific sub-channels. A sorting efficiency and a recovery efficiency of approximately 95% and 85%were achieved. This device could be used to separate small single cancer cell, as well as large cancer clusters, from MPE effectively. This miniaturized separation device is expected to be used in clinical diagnosis in the future and to help personalized cancer treatment to achieve rapid separation and detection.

1. Siegel R, Naishadham D, Jemal A. Cancer statistics, 2012. CA Cancer J Clin. 2012 Jan-Feb;62:10-29.
2. Chiang CJ, Chen YC, Chen CJ, You SL, Lai MS; Taiwan Cancer Registry Task Force. Cancer trends in Taiwan. Jpn J Clin Oncol. 2010 Oct;40:897-904.
3. Spiro SG, Silvestri GA. One hundred years of lung cancer. Am J Respir Crit Care Med. 2005 Sep;172:523-529.
4. Lin CC, Chen LC, Tseng VS, Yan JJ, Lai WW, Su WP, Lin CH, Huang CY, Su WC. Malignant pleural effusion cells show aberrant glucose metabolism gene expression. Eur Respir J. 2011 Jun;37:1453-1465.
5. Krause DS, Van Etten RA. Tyrosine kinases as targets for cancer therapy. N Engl J Med. 2005 Jul;353:172-187.
6. Lynch TJ, Bell DW, Sordella R, Gurubhagavatula S, Okimoto RA, Brannigan BW, Harris PL, Haserlat SM, Supko JG, Haluska FG, Louis DN, Christiani DC, Settleman J, Haber DA. Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med. 2004 May;350:2129-2139.
7. Uramoto H, Mitsudomi T. Which biomarker predicts benefit from EGFR-TKI treatment for patients with lung cancer? Br J Cancer. 2007 Mar;96:857-863.
8. Nagrath S, Sequist LV, Maheswaran S, Bell DW, Irimia D, Ulkus L, Smith MR, Kwak EL, Digumarthy S, Muzikansky A, Ryan P, Balis UJ, Tompkins RG, Haber DA, Toner M. Isolation of rare circulating tumour cells in cancer patients by microchip technology. Nature. 2007 Dec;450:1235-1239.
9. Wang S, Liu K, Liu J, Yu ZT, Xu X, Zhao L, Lee T, Lee EK, Reiss J, Lee YK, Chung LW, Huang J, Rettig M, Seligson D, Duraiswamy KN, Shen CK, Tseng HR. Highly efficient capture of circulating tumor cells by using nanostructured silicon substrates with integrated chaotic micromixers. Angew Chem Int Ed Engl. 2011 Mar;50:3084-3088.
10. Minerick AR, Zhou R, Takhistov P, Chang HC. Manipulation and characterization of red blood cells with alternating current fields in microdevices. Electrophoresis. 2003 Nov;24:3703-3717.
11. Hughes MP. Strategies for dielectrophoretic separation in laboratory-on-a-chip systems. Electrophoresis. 2002 Aug;23:2569-2582.
12. Fu AY, Spence C, Scherer A, Arnold FH, Quake SR. A microfabricated fluorescence-activated cell sorter. Nat Biotechnol. 1999 Nov;17:1109-1111.
13. Miltenyi S, Müller W, Weichel W, Radbruch A. High gradient magnetic cell separation with MACS. Cytometry. 1990 Jul;11:231-238.
14. Daniel C. Harris,” Exploring chemical analysis”, second edition, 2000.
15. 陳建人, 微機電系統技術與應用, 國科會精儀中心出版, 2004.
16. Manz A, Graber N, Widmer MH. Miniaturized total chemical analysis systems: a novel concept for chemical sensing. Sensor Actuat B-Chem. 1990 Jan;1: 244-248.
17. Pohl HA. “Dielectrophoresis”, Cambridge Uni. Press, 1978.
18. Li H, Bashir R. Dielectrophoretic separation and manipulation of live and heat-treated cells of Listeria on microfabricated devices with interdigitated electrodes. Sensor Actuat B-Chem. 2002 Sep;86:215-212.
19. Gagnon Z, Chang HC. Aligning fast alternating current electroosmotic flow fields and characteristic frequencies with dielectrophoretic traps to achieve rapid bacteria detection. Electrophoresis. 2005 Oct;26:3725-3737.
20. Gordon JE, Gagnon Z, Chang HC. Dielectrophoretic discrimination of bovine red blood cell starvation age by buffer selection and membrane cross-linking. Biomicrofluidics. 2007 Nov;1:44102-44105.
21. Gagnon Z, Senapati S, Gordon J, Chang HC. Dielectrophoretic detection and quantification of hybridized DNA molecules on nano-genetic particles. Electrophoresis. 2008 Dec;29:4808-4812.
22. Hagedorn R, Fuhr G, Müller T, Gimsa J. Traveling-wave dielectrophoresis of microparticles. Electrophoresis. 1992 Jan-Feb;13:49-54.
23. Wang XB, Huang Y, Becker FF and Gascoyne P. A unified theory of dielectrophoresis and traveling wave dielectrophoresis. J. Phys. D: Appl. Phys. 1994 May;27:1571-1574.
24. Masuda S, Washizu M, Iwadare M. Separation of small particles suspended in liquid by nonuniform raveling field. IEEE Trans. Ind.Appl.1987 Nov;23:474-480.
25. Masuda S, Washizu M, Kawabata I. Movement of blood cells in liquid by non-uniform traveling field. IEEE Trans. Ind. Appl.1988 Apr;24:217-222.
26. Fuhr G, Hagedorn R, Muller T. Linear motion of dielectric particles and living cells in microfabricated structures induced by traveling electric fields. Proc. IEEE MEMS. 1991 Feb;42:259-264.
27. Huang Y, Wang XB, Tame JA, Pethig R. Electrokinetic behavior of colloidal particles in travelling electric fields: studies using yeast cells. J. Phys. D: Appl. Phys. 1993 Sep;26:1528-1535.
28. Talary MS, Burt JPH, Tame JA, Pethig R. Electromanipulation and separation of cells using travelling electric fields. J. Phys. D: Appl. Phys. 1996 Nov;29:2198-2203.
29. Cheng IF, Froude VE, Zhu Y, Chang HC, Chang HC. A continuous high-throughput bioparticle sorter based on 3D traveling-wave dielectrophoresis. Lab Chip. 2009 Nov;9:3193-3201.
30. Lin CC, Huang WL, Su WP, Chen HH, Lai WW, Yan JJ, Su WC. Single cell phospho-specific flow cytometry can detect dynamic changes of phospho-Stat1 level in lung cancer cells. Cytometry A. 2010 Nov;77:1008-1019.
31. Huang WL, Yeh HH, Lin CC, Lai WW, Chang JY, Chang WT, Su WC. Signal transducer and activator of transcription 3 activation up-regulates interleukin-6 autocrine production: a biochemical and genetic study of established cancer cell lines and clinical isolated human cancer cells. Mol Cancer. 2010 Dec;9:309-325.
32. Huang Y, Wang XB, Becker FF, Gascoyne PR. Membrane changes associated with the temperature-sensitive P85gag-mos-dependent transformation of rat kidney cells as determined by dielectrophoresis and electrorotation. Biochim Biophys Acta. 1996 Jun;1282:76-84.
33. Gascoyne P, Pethig R, Satayavivad J, Becker FF, Ruchirawat M. Dielectrophoretic detection of changes in erythrocyte membranes following malarial infection. Biochim Biophys Acta. 1997 Jan;1323:240-252.
34. Wu J, Ben Y, Chang H-C. Particle detection by electrical impedance spectroscopy with asymmetric-polarization AC electroosmotic trapping. Microfluid Nanofluid. 2005 Apr;1:161-167.