title: Isolation of viable cancer cells in antibody-functionalized microfluidic devices.
abstract: Microfluidic devices functionalized with EpCAM antibodies were utilized for the capture of target cancer cells representing circulating tumor cells (CTCs). The fraction of cancer cells captured from homogeneous suspensions is mainly a function of flow shear rate, and can be described by an exponential function. A characteristic shear rate emerges as the most dominant parameter affecting the cell attachment ratio. Utilizing this characteristic shear rate as a scaling factor, all attachment ratio results for various combinations of receptor and ligand densities collapsed onto a single curve described by the empirical formula. The characteristic shear rate increases with both cell-receptor and surface-ligand densities, and empirical formulae featuring a product of two independent cumulative distributions described well these relationships. The minimum detection limit in isolation of target cancer cells from binary mixtures was experimentally explored utilizing microchannel arrays that allow high-throughput processing of suspensions about 0.5 ml in volume, which are clinically relevant, within a short time. Under a two-step attachment/detachment flow rate, both high sensitivity (almost 1.0) and high specificity (about 0.985) can be achieved in isolating target cancer cells from binary mixtures even for the lowest target/non-target cell concentration ratio of 1:100 000; this is a realistic ratio between CTCs and white blood cells in blood of cancer patients. Detection of CTCs from blood samples was also demonstrated using whole blood from healthy donors spiked with cancer cells. Finally, the viability of target cancer cells released after capture was confirmed by observing continuous cell growth in culture.
authors.affiliation: Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, Arizona 85721, USA ; College of Optical Science, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Linan
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA ; Arizona Cancer Center, University of Arizona, Tucson, Arizona 85721, USA ; BIO5 Institute, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Joyce
authors.initials: J
authors.lastname: Schroeder
authors.affiliation: Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Stopeck
authors.affiliation: Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, Arizona 85721, USA ; Arizona Cancer Center, University of Arizona, Tucson, Arizona 85721, USA ; BIO5 Institute, University of Arizona, Tucson, Arizona 85721, USA ; Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Yitshak
authors.initials: Y
authors.lastname: Zohar