Electric Field Induced Isolation, Release and Re-capture of Tumor Cells

Abstract

Profiling tumor cells present in blood based on multiple tumor-relevant markers can identify specific subpopulations of tumor cells and provide extensive information on the tumor status. Herein we present a simple approach for the analysis of tumor cells based on a combination of alternating current electrohydrodynamic (ac-EHD)-induced fluid flow for capture, release, and subsequent recapture of cells from biological fluids. Initially, tumor cell isolation was achieved using an epithelial cell adhesion molecule (EpCAM) antibody-modified ac-EHD device. Following this, captured cells were released using a DC potential pulse. Subsequently, the released cells were recaptured under ac-EHD on a separate device to specifically capture tumor derived (e.g., human epidermal growth factor receptor 2 (HER2)) cell population. We demonstrate this proof-of-concept approach for the analysis of breast cancer cells from blood samples using a purpose-built ac-EHD device. Under the optimal ac-EHD field strength, 64.8 ± 2.6% cell were captured using an anti-EpCAM functionalized device. The subsequent application of a DC potential of 1.4 V (vs Ag/AgCl) enabled 84.5 ± 3.2% release of these captured cells. Cell viability experiments showed minimal loss or damage to these released cells (14.2 ± 2%). Approximately 42.9 ± 2.4% of the released cells was recaptured using an anti-HER2 functionalized device. The device performance was reproducible with an interassay reproducibility of RSD = 6.01%, n = 3, for capture and RSD = 2.1%, n = 3, for release, respectively. We predict that this approach can potentially find its relevance as a simple tool to capture cells and efficiently retrieve these cells for subsequent analysis.