Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis

Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool.

Onset and complete trapping voltages of early (MOSE-E), early-intermediate (MOSE-E/I), intermediate (MOSE-I), and late (MOSE-L) cells at (a) 200 kHz, (b) 300 kHz, (c) 400 kHz, (d) 500 kHz, and (e) 600 kHz. Left and right columns present the onset of trapping and complete trapping, respectively. *, **, and *** indicate that data are significantly different with p < 0.0005, p < 0.005, and p < 0.05, respectively, (n = 10).

(a) 2D top view schematic of the microdevices. (b) A section of the microdevice and pillars. Each pillar is 100 μm in diameter. (c) Complete trapping of cells. Calcein AM, enzymatically converted to green fluorescent calcein, is added to the cell sample at 2 μL per mL of cell suspension.