Radiology

Magnetic resonance imaging

Nanomedicine

Nanoparticle

Nanotechnology

Chemistry

Materials science

Streptococcus mutans

Antimicrobial chemotherapy

Iron oxide nanoparticles

Dental plaque

Ferumoxytol

Antimicrobial

Bacteria

Hydrogen peroxide

Genetics

Biochemistry

Biofilm

Medicine

Biology

Microbiology

Nano Letters

Severe tooth decay has been associated with iron deficiency anemia that disproportionally burdens susceptible populations. Current modalities are insufficient in severe cases where pathogenic dental biofilms rapidly accumulate, requiring new antibiofilm approaches. Here, we show that ferumoxytol, a Food and Drug Administration-approved nanoparticle formulation for treating iron deficiency, exerts an alternative therapeutic activity via the catalytic activation of hydrogen peroxide, which targets bacterial pathogens in biofilms and suppresses tooth enamel decay in an intraoral human disease model. Data reveal the potent antimicrobial specificity of ferumoxytol iron oxide nanoparticles (FerIONP) against biofilms harboring Streptococcus mutans via preferential binding that promotes bacterial killing through in situ free-radical generation. Further analysis indicates that the targeting mechanism involves interactions of FerIONP with pathogen-specific glucan-binding proteins, which have a minimal effect on commensal streptococci. In addition, we demonstrate that FerIONP can detect pathogenic biofilms on natural teeth via a facile colorimetric reaction. Our findings provide clinical evidence and the theranostic potential of catalytic nanoparticles as a targeted anti-infective nanomedicine.

Ferumoxytol Nanoparticles Target Biofilms Causing Tooth Decay in the Human Mouth