A bold new way to watch tiny bubbles talk between our cells—and it could change how we diagnose disease and deliver therapies. But here’s the part many overlook: these little vesicles, known as extracellular vesicles and particles (EVPs), are so varied in size and cargo that pinning down their exact roles is incredibly complex. They drift through blood and other fluids and are tucked into tissues, serving as both health signals and disease messengers. Researchers are pursuing exciting uses—from early detection of illness to targeted drug delivery—thanks to their rich and mysterious contents.
In a recent Nature Methods study, Ohio State University researchers introduced a novel method to fix extracellular vesicles in place in a way that mirrors how they interact with tissue. That environment is notoriously tricky: EVPs don’t float freely; they tend to stick to surfaces. The new approach lets scientists immobilize EVPs without damaging them, enabling analysis of single vesicles or clusters and observation of how they engage with cells.
“Our goal isn’t just to know what these vesicles carry,” explained senior author Eduardo Reátegui, an associate professor of chemical and biomolecular engineering at Ohio State. “We also want to identify where they came from and how they interact with cells in the body. The key is to analyze them without destroying them.” Reátegui, who also works with the university’s Cancer Biology Program, emphasizes that this tissue-oriented view opens doors to better understanding and potential therapeutic uses.
The team’s method begins by coating a glass surface with a chemical layer and then using UV light to carve a tiny, light-driven micropattern. These patterns create spaces with an attractive electrostatic charge that draw the outer-surface proteins of EVPs, guiding them to settle precisely within the patterned regions. Computer simulations supported the idea that electrostatic forces dominate these surface interactions.
Remarkably, each type of extracellular vesicle in the experiments adhered only to the illuminated micropattern areas, without spreading beyond them. The researchers named this technique Light-Induced Extracellular Vesicle and Particle Adsorption, or LEVA.
LEVA represents a significant analytical advance, enabling new ways to study EVP behavior in tissue-like contexts. With LEVA, scientists can probe the contents of EVPs for disease biomarkers or even load therapeutic payloads and watch how cells respond—among many other possibilities.
This work builds on prior efforts by Reátegui and colleagues to immobilize EVPs for analysis using antibody-based methods. Those earlier techniques could identify molecules inside specific particle types that signaled brain cancer or immunotherapy responses, but they required a surface molecule that could be recognized by an antibody. The new surface-focused method sidesteps this bias by relying on electrostatic adsorption rather than a biological signature, allowing researchers to examine a broader population of EVPs.
“By removing the antibody-based bias, we can immobilize all EVP types and interrogate them with molecular probes or even living cells,” Reátegui notes.
One illustrative application shown in the study involved modeling early inflammation. Instead of using live pathogens, the researchers used EVPs secreted by bacteria to stimulate immune cells. They observed neutrophil swarming—the coordinated movement of neutrophils toward a site of infection—along the surfaces where bacterial EVPs bound. This demonstrated two things: first, that matrix-bound EVP contexts can be generated for straightforward analysis, and second, that EVP–tissue interactions can be studied in a tissue-like setting.
The project received support from the Ohio State Center for Cancer Engineering, Curing Cancer Through Research in Engineering Sciences; the National Institutes of Health; the Burroughs Wellcome Fund; and Ohio State’s postdoctoral programs. Co-authors span Ohio State, Nationwide Children’s Hospital, and Vanderbilt University.
If you’re curious to learn more, you can reach Eduardo Reátegui at Reategui.8@osu.edu. This summary was prepared from Ohio State University’s reporting on the study conducted by Emily Caldwell (Caldwell.151@osu.edu).
