Dielectrophoretic and electrochemical impedance mapping of metastatic potential in MDA-MB-231 breast cancer cells using inkjet-printed castellated microarray†

The spread of metastatic cancer cells poses a significant challenge in cancer treatment, making innovative approaches for early detection and diagnosis essential. Dielectrophoretic impedance spectroscopy (DEPIS), a powerful tool for cell analysis, combines dielectrophoresis (DEP) and impedance spectroscopy (IS) to separate, sort, cells and analyze their dielectric properties. In this study, we developed and built out-of-plane inkjet-printed castellated arrays to map the dielectric properties of MDA-MB-231 breast cancer cell subtypes across their metastatic potential. This was realized via modulating the expression of connexin 43 (Cx43), a marker associated with poor breast cancer prognosis and increased metastasis. We employed DEP-based trapping, followed by EIS measurements on bulk cell population, for rapid capture and differentiation of the cancer cells according to their metastatic state. Our results revealed a significant correlation between the various MDA-MB-231 metastatic subtypes and their respective dielectrophoretic and dielectric properties. Notably, cells with the highest metastatic potential exhibited the highest membrane capacitance 16.88 ± 3.24 mF m⁻², followed by the less metastatic cell subtypes with membrane capacitances below 14.3 ± 2.54 mF m⁻². In addition, highly metastatic cells exhibited lower crossover frequency (25 ± 1 kHz) compared to the less metastatic subtypes (≥27 ± 1 kHz), an important characteristic for cell sorting. Finally, EIS measurements showed distinct double layer capacitance (C_DL) values at 1 kHz between the metastatic subgroups, confirming unique dielectric and dielectrophoretic properties correlated with the metastatic state of the cell. Our findings underscore the potential of DEPIS as a non-invasive and rapid analytical tool, offering insights into cancer biology and facilitating the development of personalized therapeutic interventions tailored to distinct metastatic stages.