Aggressive Breast Cancer Cells Lose Spatial Persistence When Exposed to Wireless Electric Fields

Traditional electrotaxis assays place electrodes directly into the cell culture medium, which inevitably drives current through the sample. That current can alter pH, create chemical gradients, and even trigger electrochemical reactions which make it hard to isolate the effect of the electric field itself.

As a result, whether a flowing current is truly required for directional migration of immune and cancer cells has remained unclear. Based on these challenges, a deeper investigation into current‑free electrotaxis is needed to understand the pure electrostatic guidance of cell movement.

A team led by the University of Manitoba, Canada, reports its findings (DOI: 10.1038/s41378-026-01267-4) on 20 April 2026 in Microsystems & Nanoengineering. The Wi-EF to cells placed in a standard Petri dish. Using real‑time imaging and single‑cell tracking, they compared how human peripheral blood neutrophils (among the first responders of immune cells) and aggressive MDA‑MB‑231 breast cancer cells respond to the same wireless field.

Neutrophils required a chemical attractant (N-Formylmethionine-leucyl-phenylalanine, fMLP) to become motile, but once moving, the wireless field clearly biased them toward the cathode. The effect was modest compared to contact‑based electrotaxis, yet statistical analyses showed that cells with larger displacements displayed the strongest directional preference. When the researchers ranked cells by how far they travelled and looked only at the top 25%, the cathode‑bias became much more pronounced.

Breast cancer cells behaved very differently. Instead of heading towards or against the wireless electric field, their migration became less persistent as the field increased as the orientation index (a measure of how straight a cell moves) dropped significantly. They did not develop a left‑right bias, but their speed and turning angles increased, meaning they moved more but wandered more randomly. A unified mathematical model where a "directionality factor" and a "persistence factor" compete in a 'tug of war' manner, successfully reproduced both cell types migration responses.

"We were surprised that a purely electrostatic field, without any measurable current, could still guide neutrophils, just not as strongly as contact methods," the authors said. "That tells us current is not strictly necessary, but it probably amplifies the response. The real excitement came from the opposite behaviors: immune cells pick a side, while cancer cells simply lose their sense of direction. Our random‑walk model suggests a tug‑of‑war between field detection and natural turning noise. If we can tune that balance, wireless fields might one day help direct immune cells into tumors or keep cancer cells from migrating effectively."

The platform offers a minimally invasive way to manipulate cell migration without electrodes being in direct contact with the sample, which could be valuable for immunotherapy. Because neutrophils (and potentially T or NK cells) head toward the cathode while breast cancer cells only become less persistent, a wireless field might selectively recruit immune cells into a tumor while simultaneously disorienting cancer cells, which would be a double advantage.

Early studies have already shown that wireless fields can increase cytotoxic T cell presence at tumor sites and slow metastasis. The wireless unidirectional electric field device, compatible with microfluidics, can now test other immune‑cancer pairs and eventually may help design implantable or wearable field‑based therapies that work alongside chemoattractant gradients.