Infectious colonies of bacteria called biofilms that develop on chronic wounds and medical devices can cause serious health problems and are tough to treat.
Researchers said the new material could be used as a topical antibacterial treatment and disinfectant.
Many bacteria clump together in sticky plaques in a way that makes them difficult to eliminate with traditional antibiotics. Doctors sometimes recommend cutting out infected tissues.
This approach is costly, however, and because it is invasive, many patients opt out of treatment altogether.
Vincent M Rotello of University of Massachusetts, Amherst and his colleagues packaged peppermint oil and cinnamaldehyde, the compound in cinnamon responsible for its flavour and aroma, into silica nanoparticles.
The microcapsule treatment was effective against four different types of bacteria, including one antibiotic resistant strain. It also promoted the growth of fibroblasts, a cell type that is important in wound healing.