Differential migratory phenotypes of human neutrophils and breast cancer cells in a wireless unidirectional electric field platform.

Electric field directed migration (electrotaxis) of immune cells and breast cancer cells has been previously demonstrated with important physiological and pathological relevance. However, whether an electrical current is necessary for electrotactic cell migration is unknown, which requires engineering innovation to enable experimental investigation. Addressing this fundamental question will lead to biological implications of the electromagnetic environment exposure and raise the possibility of wireless electrical control of cell trafficking in tissues, which motivated this research. To help address this question, we developed a useful wireless unidirectional electric field (Wi-uEF) device, in where the electrochemical field is manipulated to examine migratory responses of human peripheral blood neutrophils (hPBN) and high metastatic potential MDA-MB-231 breast cancer cells. Migration of immune and cancer cells responded differently under Wi-uEF; hPBN migration is biased toward the cathode while breast cancer cells maintain overall random migration patterns. Based on these observations, we hypothesized a random-walk-based mechanistic model to predict different cell migration outcomes in Wi-uEF, and in-silico simulation captured the key experimental results. Altogether, our work is the first demonstration of the differential migratory responses of hPBN and MDA-MB-231 cancer cells to Wi-uEF and suggests a possible biophysical mechanism. Additionally, our wireless bioelectronic platform is capably developed for examining various biological cell responses in real-time in a controlled electrochemical microenvironment.