Electrical Fingerprint of Extracellular Vesicles Could Detect Pancreatic Cancer

Standard blood-based analyses can struggle to distinguish tumor signals from the background of normal cellular material. Extracellular vesicles (EVs) in circulation may carry tumor-derived information, but isolating relevant subsets remains difficult. New findings demonstrate that an electrical “fingerprint” on EVs can be exploited to enrich cancer-associated signals.

Rice University researchers developed a microfluidic electrophoresis device that separates extracellular vesicles by electrical charge to reveal pancreatic cancer–associated particles. The approach isolates a subpopulation enriched for a stronger negative charge, offering a way to study disease signals otherwise masked in bulk measurements. The work targets a diagnostic challenge where tumor-derived EVs are greatly outnumbered by vesicles released from healthy tissues.

The technology capitalizes on a physical trait that EVs already possess: surface electrical charge. In pancreatic cancer cell models, activating mutant KRAS increased EV release and produced vesicles with a stronger negative charge. The electrical signature was attributed to DNA and other materials present on the outer surface of EVs. The device moves minute amounts of blood serum through narrow channels and uses an electric field to collect the more negatively charged EV fraction.

The team evaluated the method using 112 human samples spanning healthy individuals, patients with pancreatic cancer and patients with pancreatitis. Measuring the average charge of all EVs in blood did not distinguish cancer from non-cancer samples because tumor-related particles were diluted by vesicles from normal tissues. After charge-based separation, pancreatic cancer samples showed greater enrichment of the highly negative EV population, revealing differences that bulk measurements had obscured.

The findings were published Sept. 1 in ACS Nano. Collaborators included The University of Texas MD Anderson Cancer Center, Helios University Hospital Wuppertal and Heidelberg University. According to the investigators, many existing EV methods rely on size, density or affinity capture, whereas this device enables targeted collection based on inherent electrical properties. The results suggest that sorting particles by a physical characteristic can uncover informative signals that average measurements may overlook.

“The bloodstream is an incredibly crowded environment, so the challenge is not simply finding tiny particles but identifying the ones that carry meaningful information. Our results show that electrical charge gives us another way to sort through that noise and bring a cancer-associated signal into view,” said Kshipra Kapoor, the study’s co-lead author and a Rice electrical and computer engineering doctoral alumna.

“An electrocardiogram turns the heart’s electrical activity into information doctors can use. In a similar spirit, our work suggests that the electrical properties of extracellular vesicles could one day provide another way to read biological information from cancer,” said Kapoor.

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