隨著醫療儀器以及醫學知識的進步，許多發生於人身上的疾病皆可得以控制或是治癒，但是唯有癌症仍然是現代人健康的一大威脅。而癌症最令人畏懼的階段莫過於癌症轉移，根據統計資料指出，被檢驗為肺癌初期的病人仍然有超過五成的機率存活，但是被檢驗發生癌症轉移的肺癌病人則只剩下不到5%的機會存活。早在1970年就已經提出癌症轉移與癌症腫瘤的相關研究，該研究指出當癌症腫瘤生長超過一定大小時，會因內部缺氧而釋放出血管生長因子促使周遭的微血管包覆癌症腫瘤並透過血液持續滋養腫瘤，其中最為關鍵的過程即為癌症腫瘤誘發的血管新生，因此專門抑制血管新生的藥物就油然而生，而使用此藥物治療癌症即為標靶治療。近年來有研究指出複合式治療被認為是下一代的癌症治療的希望，也就是透過傳統化療與標靶治療的結合來提高癌症腫瘤的治癒機會，這同時也是癌症治療的新方向。然而藥物測試在實務上遇到相當多的限制，其中包含費用、法律以及道德等問題。近年來蓬勃發展的微流體晶片即為醫學發展突破了這一方面的限制，提供相當良好的平台。
在過去血管新生的相關研究中，大多為直接使用已知的血管生長因子做細胞趨化性的研究，但是實際上在細胞不同的生長階段中，其所釋放的生長因子並非單一種化學物質，並且這些研究所使用的方法也與體內環境相差甚遠，因此本研究的目標在設計一結合微流體特性以及細胞機械性質微流體晶片，預期在晶片上模仿腫瘤所誘發的血管新生過程並研究之，期望在癌症腫瘤研究以及臨床癌症標靶治療上提供相關資訊。

Advances in medical research and medical equipment result in most of the diseases to be either cured or eradicated. However, cancer, the greatest threat to human-being, does not belong to them. Cancer metastasis is the most frightening part within getting cancer. Statistics from Surveillance, Epidemiology and End Results show that 5-year survival rate of patients diagnosed with stage I lung cancer is more than 50%. However, 5-year survival rate of patients diagnosed with IV lung cancer is less than 5%. Relative research on cancer metastasis and tumor has been proposed in 1970s. Those reports showed that as tumor size exceeding certain dimension it will secret vascular endothelial growth factor to stimuli microvascular around itself if the tumor is lack of nutrition inside. The induced microvascular will migrate and proliferate toward the tumor body and provides nutrition to nourish it where the process is called angiogenesis which is a crucial process within cancer metastasis. Based on this, a kind of cancer therapy using angiogenic inhibitors for cancer treatment was proposed and known as targeted therapy. In recent years, targeted therapy in combination with chemotherapy has been considered to be a new dawn for cancer treatment. However, drug testing, in practice, was restricted by various reasons including the cost, the law and the ethical problems. Thankfully, these restrictions could be eliminated due to the advance in microfluidics technology which provides an excellent platform for biomedical application.
In the past, most research on angiogenesis showed the direct use of one kind of known growth factor for cell chemotaxis study. In reality, there are various unknown factors being secreted during a cell cycle. Approaches used in those reports are still far from the in vivo condition. For this reason, this project is expected to build a microfluidic device which integrates the microscale fluid properties and cell mechanical properties for mimicking the cell induced angiogenesis in vitro. We expect this in vitro model could provide helpful information for clinical trial and cancer tumor study.

[1] N. T. Nguyen and S. T. Wereley, Fundamentals and Applications of Microfluidics, Artech House, 2002.
[2] S. Paget, "The distribution of secondary growths in cancer of the breast. 1889," Cancer Metastasis Rev, vol. 8, pp. 98-101, Aug 1989.
[3] I. J. Fidler, "The pathogenesis of cancer metastasis: the 'seed and soil' hypothesis revisited," Nat Rev Cancer, vol. 3, pp. 453-8, Jun 2003.
[4] J. Folkman, "Tumor angiogenesis: therapeutic implications," N Engl J Med, vol. 285, pp. 1182-6, Nov 18 1971.
[5] N. C. Institute. (2010, July 1). SEER Stat Fact Sheets: Lung and Bronchus Cancer. Available: http://seer.cancer.gov/statfacts/html/lungb.html
[6] I. International Early Lung Cancer Action Program, C. I. Henschke, D. F. Yankelevitz, D. M. Libby, M. W. Pasmantier, J. P. Smith, et al., "Survival of patients with stage I lung cancer detected on CT screening," N Engl J Med, vol. 355, pp. 1763-71, Oct 26 2006.
[7] J. K. Gohagan, P. M. Marcus, R. M. Fagerstrom, P. F. Pinsky, B. S. Kramer, P. C. Prorok, et al., "Final results of the Lung Screening Study, a randomized feasibility study of spiral CT versus chest X-ray screening for lung cancer," Lung Cancer, vol. 47, pp. 9-15, Jan 2005.
[8] J. D. Hardcastle, J. O. Chamberlain, M. H. Robinson, S. M. Moss, S. S. Amar, T. W. Balfour, et al., "Randomised controlled trial of faecal-occult-blood screening for colorectal cancer," Lancet, vol. 348, pp. 1472-7, Nov 30 1996.
[9] S. J. Winawer, B. J. Flehinger, D. Schottenfeld, and D. G. Miller, "Screening for colorectal cancer with fecal occult blood testing and sigmoidoscopy," J Natl Cancer Inst, vol. 85, pp. 1311-8, Aug 18 1993.
[10] L. L. Humphrey, M. Helfand, B. K. Chan, and S. H. Woolf, "Breast cancer screening: a summary of the evidence for the U.S. Preventive Services Task Force," Ann Intern Med, vol. 137, pp. 347-60, Sep 3 2002.
[11] M. G. Marmot, D. G. Altman, D. A. Cameron, J. A. Dewar, S. G. Thompson, and M. Wilcox, "The benefits and harms of breast cancer screening: an independent review," Br J Cancer, vol. 108, pp. 2205-2240, 06/11/print 2013.
[12] H. F. Dvorak, L. F. Brown, M. Detmar, and A. M. Dvorak, "Vascular permeability factor/vascular endothelial growth factor, microvascular hyperpermeability, and angiogenesis," Am J Pathol, vol. 146, pp. 1029-39, May 1995.
[13] T. P. Butler and P. M. Gullino, "Quantitation of cell shedding into efferent blood of mammary adenocarcinoma," Cancer Res, vol. 35, pp. 512-6, 1975.
[14] N. Weidner, J. P. Semple, W. R. Welch, and J. Folkman, "Tumor angiogenesis and metastasis--correlation in invasive breast carcinoma," N Engl J Med, vol. 324, pp. 1-8, 1991.
[15] J. Folkman, "Anti-angiogenesis: new concept for therapy of solid tumors," Ann Surg, vol. 175, pp. 409-16, Mar 1972.
[16] B. R. Zetter, "Angiogenesis and tumor metastasis," Annu Rev Med, vol. 49, pp. 407-24, 1998.
[17] B. A. Teicher, E. A. Sotomayor, and Z. D. Huang, "Antiangiogenic agents potentiate cytotoxic cancer therapies against primary and metastatic disease," Cancer Res, vol. 52, pp. 6702-4, Dec 1 1992.
[18] B. A. Teicher, S. A. Holden, G. Ara, E. A. Sotomayor, Z. D. Huang, Y. N. Chen, et al., "Potentiation of cytotoxic cancer therapies by TNP-470 alone and with other anti-angiogenic agents," Int J Cancer, vol. 57, pp. 920-5, Jun 15 1994.
[19] N. Klauber, R. M. Rohan, E. Flynn, and R. J. D'Amato, "Critical components of the female reproductive pathway are suppressed by the angiogenesis inhibitor AGM-1470," Nat Med, vol. 3, pp. 443-6, Apr 1997.
[20] J. Folkman, "Fighting cancer by attacking its blood supply," Sci Am, vol. 275, pp. 150-4, Sep 1996.
[21] B. P. AG. (2014, July 1). Processes in Research and Development. Available: http://www.bayerpharma.com/en/research-and-development/processes/index.php
[22] J. Pihl, J. Sinclair, E. Sahlin, M. Karlsson, F. Petterson, J. Olofsson, et al., "Microfluidic gradient-generating device for pharmacological profiling," Anal Chem, vol. 77, pp. 3897-903, Jul 1 2005.
[23] A. Tourovskaia, X. Figueroa-Masot, and A. Folch, "Differentiation-on-a-chip: a microfluidic platform for long-term cell culture studies," Lab Chip, vol. 5, pp. 14-9, Jan 2005.
[24] J. Shao, L. Wu, J. Wu, Y. Zheng, H. Zhao, Q. Jin, et al., "Integrated microfluidic chip for endothelial cells culture and analysis exposed to a pulsatile and oscillatory shear stress," Lab Chip, vol. 9, pp. 3118-25, Nov 7 2009.
[25] J. W. Song, W. Gu, N. Futai, K. A. Warner, J. E. Nor, and S. Takayama, "Computer-controlled microcirculatory support system for endothelial cell culture and shearing," Anal Chem, vol. 77, pp. 3993-9, Jul 1 2005.
[26] L. J. Millet, M. E. Stewart, J. V. Sweedler, R. G. Nuzzo, and M. U. Gillette, "Microfluidic devices for culturing primary mammalian neurons at low densities," Lab Chip, vol. 7, pp. 987-94, 2007.
[27] C. T. Ho, R. Z. Lin, R. J. Chen, C. K. Chin, S. E. Gong, H. Y. Chang, et al., "Liver-cell patterning lab chip: mimicking the morphology of liver lobule tissue," Lab Chip, vol. 13, pp. 3578-87, Sep 21 2013.
[28] W. Saadi, S. J. Wang, F. Lin, and N. L. Jeon, "A parallel-gradient microfluidic chamber for quantitative analysis of breast cancer cell chemotaxis," Biomed Microdevices, vol. 8, pp. 109-18, Jun 2006.
[29] S. Boyden, "The chemotactic effect of mixtures of antibody and antigen on polymorphonuclear leucocytes," J Exp Med, vol. 115, pp. 453-66, Mar 1 1962.
[30] D. Zicha, G. A. Dunn, and A. F. Brown, "A new direct-viewing chemotaxis chamber," J Cell Sci, vol. 99 ( Pt 4), pp. 769-75, Aug 1991.
[31] T. M. Keenan and A. Folch, "Biomolecular gradients in cell culture systems," Lab Chip, vol. 8, pp. 34-57, Jan 2008.
[32] S. H. Zigmond, "Ability of polymorphonuclear leukocytes to orient in gradients of chemotactic factors," J Cell Biol, vol. 75, pp. 606-16, Nov 1977.
[33] N. Probe. (2013, July 1). Neuro Probe Zigmond Chamber. Available: http://www.neuroprobe.com/product/neuro-probe-zigmond-chamber/
[34] G. A. D. ProSciTech Pty Ltd. (2014, July 1). Dunn Chemotaxis Chamber, User notes for Dunn Chemotaxis chamber, SVDCC100. Available: http://laboratoryresource.com.au/?navaction=getitem&id=119
[35] N. L. Jeon, S. K. W. Dertinger, D. T. Chiu, I. S. Choi, A. D. Stroock, and G. M. Whitesides, "Generation of Solution and Surface Gradients Using Microfluidic Systems," Langmuir, vol. 16, pp. 8311-8316, 2000/10/01 2000.
[36] B. G. Chung, L. A. Flanagan, S. W. Rhee, P. H. Schwartz, A. P. Lee, E. S. Monuki, et al., "Human neural stem cell growth and differentiation in a gradient-generating microfluidic device," Lab Chip, vol. 5, pp. 401-6, Apr 2005.
[37] D. L. Englert, M. D. Manson, and A. Jayaraman, "Flow-based microfluidic device for quantifying bacterial chemotaxis in stable, competing gradients," Appl Environ Microbiol, vol. 75, pp. 4557-64, Jul 2009.
[38] B. Y. Xu, S. W. Hu, G. S. Qian, J. J. Xu, and H. Y. Chen, "A novel microfluidic platform with stable concentration gradient for on chip cell culture and screening assays," Lab Chip, vol. 13, pp. 3714-20, Sep 21 2013.
[39] N. Ye, J. Qin, W. Shi, X. Liu, and B. Lin, "Cell-based high content screening using an integrated microfluidic device," Lab Chip, vol. 7, pp. 1696-704, 2007.
[40] S. W. Hu, B. Y. Xu, J. J. Xu, and H. Y. Chen, "Liquid gradient in two-dimensional matrix for high throughput screening," Biomicrofluidics, vol. 7, p. 64116, 2013.
[41] J. Atencia, J. Morrow, and L. E. Locascio, "The microfluidic palette: A diffusive gradient generator with spatio-temporal control," Lab Chip, vol. 9, pp. 2707-2714, 2009.
[42] K. M. Chrobak, D. R. Potter, and J. Tien, "Formation of perfused, functional microvascular tubes in vitro," Microvasc Res, vol. 71, pp. 185-96, May 2006.
79
[43] S. Chung, R. Sudo, P. J. Mack, C.-R. Wan, V. Vickerman, and R. D. Kamm, "Cell migration into scaffolds under co-culture conditions in a microfluidic platform," Lab Chip, vol. 9, pp. 269-75, 2009.
[44] D. H. Nguyen, S. C. Stapleton, M. T. Yang, S. S. Cha, C. K. Choi, P. A. Galie, et al., "Biomimetic model to reconstitute angiogenic sprouting morphogenesis in vitro," Proc Natl Acad Sci U S A, vol. 110, pp. 6712-7, Apr 23 2013.
[45] Y. Shin, S. Han, J. S. Jeon, K. Yamamoto, I. K. Zervantonakis, R. Sudo, et al., "Microfluidic assay for simultaneous culture of multiple cell types on surfaces or within hydrogels," Nat Protoc, vol. 7, pp. 1247-59, 2012.
[46] J. H. Yeon, H. R. Ryu, M. Chung, Q. P. Hu, and N. L. Jeon, "In vitro formation and characterization of a perfusable three-dimensional tubular capillary network in microfluidic devices," Lab Chip, vol. 12, pp. 2815-22, Aug 21 2012.
[47] S. Kim, H. Lee, M. Chung, and N. L. Jeon, "Engineering of functional, perfusable 3D microvascular networks on a chip," Lab Chip, vol. 13, pp. 1489-500, Apr 21 2013.
[48] A. Shamloo, N. Ma, M. M. Poo, L. L. Sohn, and S. C. Heilshorn, "Endothelial cell polarization and chemotaxis in a microfluidic device," Lab Chip, vol. 8, pp. 1292-9, Aug 2008.
[49] Unger, M A, Chou, H P, Thorsen, T, Scherer, A, and Quake, S R, "Monolithic microfabricated valves and pumps by multilayer soft lithography," Science, vol. 288, pp. 113-6, 2000.