In the tiny grooves of surgical forceps, millions of bacteria can hide from the strongest cleaners—protected by a sticky shield that even decades-old methods cannot crack. Now, scientists at the University of Illinois Urbana-Champaign have built something small enough to reach those hiding spots: microscopic particles that swim through bacterial films and blast them apart from the inside.
The team, led by Professor Hyunjoon Kong from the Department of Chemical and Biomolecular Engineering, created tiny cylinders made of biosilica coated in manganese dioxide, a catalyst. When placed in hydrogen peroxide solution, the coating triggers a reaction that releases tiny oxygen bubbles. Those bubbles push the particles deeper into bacterial films called biofilms—sticky mats of bacteria and proteins that cling to wounds and medical tools alike. The bubbles keep forming, propelling the particles forward and breaking the biofilm apart.
"Biofilms are a dense matrix of bacterial cells and proteins," Kong explained. "While sterilizing agents can kill bacteria, the matrix protects them, making it much harder to treat or clean with chemicals. Hydrogen peroxide has been used for centuries but only cleanses the surface and does not penetrate the film. We take a mechanical approach: Our particles infiltrate the biofilm first and then generate bubbles inside the matrix, disrupting it."
The researchers tested the particles on surgical instruments, where biofilms can survive even after standard cleaning. They compared biofilms remaining in the serrated teeth of forceps after typical treatment—enzymatic detergents plus high-heat autoclaving—against treatment with their bubble-making particles. The results showed a fivefold reduction in remaining biofilm when particles were used, especially at higher temperatures. Even better, the particles reached into tiny crevices that liquid cleaners cannot enter.
"With our particle system, we could actually remove the films in those spaces," Kong said. "That's a huge difference."
The team also embedded the particles into bandages for wounded patients. Chronic wounds—slow-healing sores that affect roughly 10.5 million Medicare recipients in the United States—harbor biofilms in 60 to 80 percent of cases, making them incredibly difficult to treat with antibiotics alone. The researchers called their wound dressing the "microblasting bandage" because it continuously releases hydrogen peroxide, activating the hidden particles to scrub the wound surface with tiny bubbles.
On mouse wounds infected with antibiotic-resistant bacteria—the kind commonly found in human patients—the microblasting dressing dramatically accelerated healing. Graduate student Joo Hun Lee, who led the surgical instrument research, and postdoctoral researcher Yujin Ahn, who spearheaded the wound dressing study, both published their findings in peer-reviewed journals: ACS Applied Materials and Interfaces and Advanced Science, respectively.
The technology is still being developed, but it points toward a future where stubborn infections and contaminated tools might be cleaned without relying solely on antibiotics or harsh chemicals—using tiny bubbles as nature's scrubbing brush.