title: Development of a microfluidic-based optical sensing device for label-free detection of circulating tumor cells (CTCs) through their lactic acid metabolism.
abstract: This study reports a microfluidic-based optical sensing device for label-free detection of circulating tumor cells (CTCs), a rare cell species in blood circulation. Based on the metabolic features of cancer cells, live CTCs can be quantified indirectly through their lactic acid production. Compared with the conventional schemes for CTC detection, this label-free approach could prevent the biological bias due to the heterogeneity of the surface antigens on cancer cells. In this study, a microfluidic device was proposed to generate uniform water-in-oil cell-encapsulating micro-droplets, followed by the fluorescence-based optical detection of lactic acid produced within the micro-droplets. To test its feasibility to quantify cancer cells, experiments were carried out. Results showed that the detection signals were proportional to the number of cancer cells within the micro-droplets, whereas such signals were insensitive to the existence and number of leukocytes within. To further demonstrate its feasibility for cancer cell detection, the cancer cells with known cell number in a cell suspension was detected based on the method. Results revealed that there was no significant difference between the detected number and the real number of cancer cells. As a whole, the proposed method opens up a new route to detect live CTCs in a label-free manner.
authors: Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan. b74225@hotmail.com.
authors: Tzu-Keng
authors: TK
authors: Chiu
authors: Graduate Institute of Medical Mechatronics, Chang Gung University, Taoyuan 33302, Taiwan. kflei@mail.cgu.edu.tw.|Department of Mechanical Engineering, Chang Gung University, Taoyuan 33302, Taiwan. kflei@mail.cgu.edu.tw.
authors: Kin-Fong
authors: KF
authors: Lei
authors: Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan. wisdom5000@gmail.com.|Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkuo, Taoyuan 33302, Taiwan. wisdom5000@gmail.com.
authors: Chia-Hsun
authors: CH
authors: Hsieh
authors: Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan. harber0815@gmail.com.
authors: Hung-Bo
authors: HB
authors: Hsiao
authors: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan 33302, Taiwan. whm526@gmail.com.
authors: Hung-Ming
authors: HM
authors: Wang
authors: Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan. mhwu@mail.cgu.edu.tw.
authors: Min-Hsien
authors: MH
authors: Wu
mesh_terms: D015374:Biosensing Techniques; D045744:Cell Line, Tumor; D002469:Cell Separation; D002470:Cell Survival; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D007962:Leukocytes / Q000378:metabolism / Q000473:pathology; D046210:Microfluidic Analytical Techniques; D009369:Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D009360:Neoplastic Cells, Circulating / Q000378:metabolism* / Q000473:pathology; D055096:Optical Devices
chemical_list: D019344:Lactic Acid