ApoStream™, a new dielectrophoretic device for antibody independent isolation and recovery of viable cancer cells from blood

Abstract

Isolation and enumeration of circulating tumor cells (CTCs) are used to monitor metastatic disease progression and guide cancer therapy. However, currently available technologies are limited to cells expressing specific cell surface markers, such as epithelial cell adhesion molecule (EpCAM) or have limited specificity because they are based on cell size alone. We developed a device, ApoStream TM that overcomes these limitations by exploiting differences in the biophysical characteristics between cancer cells and normal, healthy blood cells to capture CTCs using dielectrophoretic technology in a microfluidic flow chamber. Further, the system overcomes throughput limitations by operating in continuous mode for efficient isolation and enrichment of CTCs from blood. The performance of the device was optimized using a design of experiment approach for key operating parameters such as frequency, voltage and flow rates, and buffer formulations. Cell spiking studies were conducted using SKOV3 or MDA-MB-231 cell lines that have a high and low expression level of EpCAM, respectively, to demonstrate linearity and precision of recovery independent of EpCAM receptor levels. The average recovery of SKOV3 and MDA-MB-231 cancer cells spiked into approximately 12 Â 10 6 peripheral blood mononuclear cells obtained from 7.5 ml normal human donor blood was 75.4% 6 3.1% (n ¼ 12) and 71.2% 6 1.6% (n ¼ 6), respectively. The intra-day and inter-day precision coefficients of variation of the device were both less than 3%. Linear regression analysis yielded a correlation coefficient (R

Enhanced contactless dielectrophoresis enrichment and isolation platform via cell-scale microstructures

“…On the other hand, the amplitude of the DEP force decreases significantly when the cells move away from the electrodes. Viability of mammalian cells in negative DEP devices, where the DEP force is pushing the cells away from electrodes, can be as high as 97%; 27 however, to the authors' knowledge, no viability study has been published on trapping-based high-throughput DEP systems. Development of 3D electrodes has allowed for extended range of the DEP force and higher throughput 20,28 at the cost of more complex fabrication.…”

Dielectrophoretic capture of low abundance cell population using thick electrodes

“…Other works report continuous separation of cancer cells using DEP at higher flow rate. [43][44][45] In this paper, we demonstrated the interest of C-PDMS to perform cell immobilization which requires to fully compensate the drag force. Having demonstrated the interest of thick C-PDMS based electrodes for such a challenging goal, it would be interesting to evaluate in a future work the performances of this conductive composite for continuous separation of cancer cells.…”

Increasing label-free stem cell sorting capacity to reach transplantation-scale throughput

“…3 Although cell sorting rates of greater than 10 5 cells/s have been demonstrated with DEP-based sorting devices, many of these high throughput devices sorted yeast 24 and bacteria 3 and they have not been validated with mammalian cells. Impressive sorting rates of up to 17,000 cells/s have been demonstrated in mammalian cell separations such as the isolation of breast cancer cells from blood, 25,26 leukemia cells from blood, 22 and circulating colon tumor cells from blood. 27 Many of these separations were aided by labels 28 or a difference in size between the cells of interest and background cells.…”