Nanocatalysts promote Streptococcus mutans biofilm matrix degradation and enhance bacterial killing to suppress dental caries in vivo

Biomaterials. 2016 Sep;101:272-84. doi: 10.1016/j.biomaterials.2016.05.051. Epub 2016 Jun 2.


Dental biofilms (known as plaque) are notoriously difficult to remove or treat because the bacteria can be enmeshed in a protective extracellular matrix. It can also create highly acidic microenvironments that cause acid-dissolution of enamel-apatite on teeth, leading to the onset of dental caries. Current antimicrobial agents are incapable of disrupting the matrix and thereby fail to efficiently kill the microbes within plaque-biofilms. Here, we report a novel strategy to control plaque-biofilms using catalytic nanoparticles (CAT-NP) with peroxidase-like activity that trigger extracellular matrix degradation and cause bacterial death within acidic niches of caries-causing biofilm. CAT-NP containing biocompatible Fe3O4 were developed to catalyze H2O2 to generate free-radicals in situ that simultaneously degrade the biofilm matrix and rapidly kill the embedded bacteria with exceptional efficacy (>5-log reduction of cell-viability). Moreover, it displays an additional property of reducing apatite demineralization in acidic conditions. Using 1-min topical daily treatments akin to a clinical situation, we demonstrate that CAT-NP in combination with H2O2 effectively suppress the onset and severity of dental caries while sparing normal tissues in vivo. Our results reveal the potential to exploit nanocatalysts with enzyme-like activity as a potent alternative approach for treatment of a prevalent biofilm-associated oral disease.

Keywords: Antibacterial; Biofilms; Catalysis; Dental caries; Extracellular matrix; Iron oxide; Nanoparticles.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry*
  • Anti-Bacterial Agents / pharmacology*
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / pharmacology
  • Biofilms / drug effects*
  • Catalysis
  • Cell Line
  • Dental Caries / drug therapy
  • Dental Caries / metabolism
  • Dental Caries / microbiology
  • Ferrosoferric Oxide / chemistry*
  • Ferrosoferric Oxide / pharmacology*
  • Humans
  • Hydrogen Peroxide / metabolism
  • Nanoparticles / chemistry*
  • Peroxidase / chemistry
  • Peroxidase / pharmacology
  • Streptococcus mutans / drug effects*
  • Streptococcus mutans / physiology


  • Anti-Bacterial Agents
  • Biocompatible Materials
  • Hydrogen Peroxide
  • Peroxidase
  • Ferrosoferric Oxide