Oral biofilm elimination by combining iron-based nanozymes and hydrogen peroxide-producing bacteria
Dental caries is a global risk of oral health for many schoolchildren and vast majority of adults. The primary factor for caries formation is that bacteria attach on tooth surface to form an oral biofilm which generates acids to demineralize calcium and eventually cause tooth decay. It is still challenging for oral biofilm elimination because bacteria are embedded inside with the protection by biofilm matrix to prevent the penetration of antibiotics or bactericides. Promising strategies to disrupt oral biofilm have been developed, including using natural enzymes to degrade biofilm matrix and hydrogen peroxide to kill bacteria. Here we demonstrate a strategy combining nanozymes with peroxidase-like activity and bacteria generating biogenic hydrogen peroxide to eliminate oral biofilm for caries treatment. By using saliva-coated hydroxyapatite disc and sectioned human tooth to mimick real oral environment, we analyze the influence of iron oxide nanozymes or iron sulfide nanozymes on Streptococcus mutans biofilm in the presence of Streptococcus gordonii which can generate hydrogen peroxide . Bacterial viability assays and biofilm morphology characterizations show that the combination of nanozymes and bacteria remarkably reduce bacteria number (5 lg reduction) and biofilm matrix (85% reduction). Therefore, the combination of iron-based nanozymes and hydrogen peroxide-generating bacteria may provide a new strategy for oral biofilm elimination in dental caries treatment.
- This article is part of the themed collection: Biomimetic Therapeutics