Characterization of microfluidic shear-dependent epithelial cell adhesion molecule immunocapture and enrichment of pancreatic cancer cells from blood cells with dielectrophoresis

Abstract

Current microfluidic techniques for isolating circulating tumor cells (CTCs) from cancer patient blood are limited by low capture purity, and dielectrophoresis (DEP) has the potential to complement existing immunocapture techniques to improve capture performance. We present a hybrid DEP and immunocapture Hele-Shaw flow cell to characterize DEP's effects on immunocapture of pancreatic cancer cells (Capan-1, PANC-1, and BxPC-3) and peripheral blood mononuclear cells (PBMCs) with an anti-EpCAM (epithelial cell adhesion molecule) antibody. By carefully specifying the applied electric field frequency, we demonstrate that pancreatic cancer cells are attracted to immunocapture surfaces by positive DEP whereas PBMCs are repelled by negative DEP. Using an exponential capture model to interpret our capture data, we show that immunocapture performance is dependent on the applied DEP force sign and magnitude, cell surface EpCAM expression level, and shear stress experienced by cells flowing in the capture device. Our work suggests that DEP can not only repel contaminating blood cells but also enhance capture of cancer cell populations that are less likely to be captured by traditional immunocapture methods. This combination of DEP and immunocapture techniques to potentially increase CTC capture purity can facilitate subsequent biological analyses of captured CTCs and research on cancer metastasis and drug therapies. V C 2014 AIP Publishing LLC. [http://dx

Automated electrorotation shows electrokinetic separation of pancreatic cancer cells is robust to acquired chemotherapy resistance, serum starvation, and EMT

“…The robustness of the distinguishing electrical properties to the applied treatments is promising for DEP-enhanced cell capture devices, as proposed in the other work. 17,18,20 Furthermore, these measurements revealed a higher cytoplasmic permittivity than has been previously reported in the literature, which predicts that no upper crossover frequency exists and could be the study of future investigation. Future work could involve studying ROT of cancer cells at higher frequencies to validate this measurement and DEP at higher frequencies to exploit permittivity mismatches to separate cells.…”

“…These values are higher than those from ROT experiments of T lymphocytes and MDA321 breast cancer cells (64 and 52) reported by Becker et al 16 and used by many subsequent studies. 14,17,18,51 The dielectric increment of glycine in water is positive, 23,52 whereas the dielectric increment of salts is negative, 23,53 so their competing effect on the permittivity of cytoplasm is unclear. The concentration of either type of solute could be different in cells with a highly dysregulated growth and metabolism.…”

“…[14][15][16] A proof-of-concept hybrid DEP-immunoaffinity device has shown promise of further improving capture. [17][18][19] Careful device design and frequency selection can attract CTCs while repelling contaminating white blood cells, and simulations have predicted capture efficiency increases of up to 400%. 20 The upper half of Figure 1 shows measured DEP spectra for different white blood cells and cancer cell lines.…”

Three dimensional passivated-electrode insulator-based dielectrophoresis

“…This technique has been widely used in biological applications to characterize yeast, 2 bacteria, 3 and mammalian cells. [4][5][6][7] Electrode based DEP (eDEP) technique is normally used to generate non-uniform electric fields in the channel. 8,9 Micro-patterned electrodes in the channel generate highly localized electric fields and trapping is observed to be concentrated around the electrodes.…”

A transfer function approach for predicting rare cell capture microdevice performance

“…The constants A and B are experimentallydetermined, unique to cell type and surface chemistry system, and are measured by data fitting to the results of capture characterization experiments in a Hele-Shaw flow chamber designed to expose cells to a range of shear stresses Huang et al 2014). This work uses LNCaP human prostate adenocarcinoma cells and J591, a monoclonal antibody that binds to the prostate-specific membrane antigen (PSMA) expressed on the LNCaP cell membrane, as a model system.…”