Capture of rare circulating tumor cells from blood on bio-activated oxide surface inside microfluidic channels

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2018

Öğrenci: HATİCE CEREN ATEŞ

Danışman: HALUK KÜLAH

Özet:

Isolation and characterization of circulating tumor cells (CTCs) have important clinical significance in terms of prognosis and early detection of response to treatment. Moreover, downstream characterization of CTCs may help better patient stratification and therapy guidance. However, CTCs are extremely rare (~10 CTCs/1010 peripheral blood cells) and highly sensitive, and specific technology is required for their isolation. Rapidly developing microfluidic technologies offer variety of advantages in rare cell isolation including rapid, low-cost and automated sample procesing, and higher sensitivity and specificity due to their similar physical dimenions to biological cells. Many of these technologies utilize immuno-affinity based CTC capture, where anti-EpCAM antibody against epithelial cell surface biomarker is widely utilized for CTC-specific cell capture. In such applications, a proper antibody immobilization plays a crucial role for high efficiency cell capture. In this study, development and evaluation of four different surface modification approaches to immobilize anti-EpCAM on the silicon oxide surfaces was presented and the selected modification method is implemented in microfluidic channels. Cell capture efficiency and capture specificity were determined using different breast cancer cell lines as a CTC model. Selective CTC capture was demonstrated using breast cancer cells (MCF-7) spiked in buffer containing background leukocytes with cell concentration ratio of 1:104. Cell capture efficiency and specificity of 90% and 87% have been achieved, respectively, with MCF7 cells. Besides, protocols for in-channel immunofluorecent cell staining and viable cell release have been developed. Shelf life of the functionalized surfaces was also determined by inspecting the capture efficiency of microchannels weekly.