Improving the purity of negative selection-/immunomagnetic microbeads-based circulating tumor cells (CTCs) isolation by optically induced dielectrophoresis (ODEP)-based microfluidic device
Min-Hsien Wu1,2,3 and Po-Yu Chu4
1Division of Haematology/Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan City, Taiwan (R. O. C.)
2Graduate Institute of Biomedical Engineering, Chang Gung University, Taoyuan City, Taiwan (R. O. C.)
3Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, Taiwan (R. O. C.)
4Ph.D. Program in Biomedical Engineering, Chang Gung University, Taoyuan City, Taiwan (R. O. C.)
mhwu@mail.cgu.edu.tw
Abstract
Circulating tumor cells (CTCs) are those cells that escape from the primary tumor tissue and present in the blood circulation. The isolation and purification of CTCs holds great promise for the subsequent cells-, or molecules-based analysis for fundamental research or precision cancer care. By removing the red blood cells (RBCs) and leukocytes in a blood sample, negative selection-based CTC isolation is able to harvest viable, label-free, and clinically meaningful CTCs from the cancer patients’ blood. However, its main shortcoming is its inability to isolate high-purity CTCs, restricting subsequent CTC-related analysis and applications. To tackle the technical hurdle, this study proposed a two-step optically-induced dielectrophoresis (ODEP) cell manipulation to process the cell sample harvested by negative selection-/immunomagnetic microbeads-based CTC isolation. The working mechanism is that the ODEP force acting on the cells with and without magnetic microbeads binding is different. Accordingly, the use of ODEP cell manipulation in a microfluidic system was designed to first separate and then isolate the cancer cells from other magnetic microbead-bound cells. Immunofluorescent microscopic observation and ODEP cell manipulation were then performed to refine the purity of the cancer cells. In this study, the optimum operating conditions for effective cell isolation were determined experimentally. The results revealed that the presented method was able to further refine the purity of cancer cell in the sample obtained after negative selection-based CTC isolation with high cell purity (81.6~86.1%). Overall, this study proposed the combination of immunomagnetic bead-based cell isolation and ODEP cell manipulation for the negative selection-based isolation of CTCs.
Short Bio
Min-Hsien Wu is currently a Distinguished Professor in the Graduate Institute of Biomedical Engineering at Chang Gung University, Taiwan. He received his B.S. and M.S. degrees from the Department of Food Science at Tung-Hai University, Taiwan in 1994 and in Applied Biomolecular Technology from the University of Nottingham, UK in 2002, respectively. He received his Ph.D. from the Department of Engineering Science at the University of Oxford, UK in 2005. His research focus is in the area of microfluidic technology (e.g., for high-throughput perfusion 3-D cell culture and for circulating tumor cell study) and bio-sensing (e.g., nucleic acid amplification and detection). He has published over 90 peer-reviewed articles, and over 15 patents granted. He received several national innovation awards, holds journal editorial board memberships for several journals.