IADR Abstract Archives
Iron-Oxide Nanoparticles Disrupt Enterococcus Faecalis in Endodontic Biofilm Models
Objectives: Iron-oxide nanoparticles (IONP) exhibit potent catalytic activity (peroxidase mimics), which has shown therapeutic activity against biofilm-forming pathogenic microbes. The reduction or elimination of microorganisms in endodontic biofilm infections has been associated with positive clinical outcomes. However, conventional irrigants fail to completely eliminate bacterial biofilm within the root canal system. Therefore, we assessed the potential of IONP catalytic system to locally activate H2O2 and target Enterococcus faecalis viability within single and multispecies biofilms.
Methods: The catalytic properties of IONP in suspension or associated to bacterial surfaces were characterized via colorimetric and inductively coupled plasma mass spectrometry analyses. The antimicrobial activity of the IONP/H2O2 system against actively growing E. faecalis OG1RF, was assessed in a dose- and time-dependent manner via biochemical and microbiological methods. Mono- and multi-species E. faecalis biofilms (with Fusobacterium nucleatum, Streptococcus gordonii and Actinomyces israelii) formed on vertical apatitic surfaces were treated in a dose- and time-dependent fashion. E. faecalis and other bacterial species used in our model are among the species commonly found in post-treatment endodontic infections. Antibiofilm activity was assessed via biochemical, microbiological and fluorescence-based methods.
Results: The data revealed that IONP rapidly catalyzed 3% H2O2 to generate reactive oxygen species (ROS) in situ in a dose dependent fashion. Notably, IONP bound to bacterial cells retained their intrinsic catalytic activity and rapidly catalyzed H2O2 to generate ROS suggesting the mechanism for the antimicrobial killing. The antimicrobial and antibiofilm bacterial killing effect of the IONP/H2O2 followed a dose- and time-dependent trends (6mg/ml IONP achieved complete killing of planktonic cells and biofilms of Enterococcus faecalis within 5 minutes and 10 minutes respectively).
Conclusions: Our results indicate the potential to exploit iron oxide nanoparticles with intrinsic catalytic activity as a potent alternative or adjunctive antimicrobial agent for the treatment of bacterial biofilms associated with endodontic infections.
Methods: The catalytic properties of IONP in suspension or associated to bacterial surfaces were characterized via colorimetric and inductively coupled plasma mass spectrometry analyses. The antimicrobial activity of the IONP/H2O2 system against actively growing E. faecalis OG1RF, was assessed in a dose- and time-dependent manner via biochemical and microbiological methods. Mono- and multi-species E. faecalis biofilms (with Fusobacterium nucleatum, Streptococcus gordonii and Actinomyces israelii) formed on vertical apatitic surfaces were treated in a dose- and time-dependent fashion. E. faecalis and other bacterial species used in our model are among the species commonly found in post-treatment endodontic infections. Antibiofilm activity was assessed via biochemical, microbiological and fluorescence-based methods.
Results: The data revealed that IONP rapidly catalyzed 3% H2O2 to generate reactive oxygen species (ROS) in situ in a dose dependent fashion. Notably, IONP bound to bacterial cells retained their intrinsic catalytic activity and rapidly catalyzed H2O2 to generate ROS suggesting the mechanism for the antimicrobial killing. The antimicrobial and antibiofilm bacterial killing effect of the IONP/H2O2 followed a dose- and time-dependent trends (6mg/ml IONP achieved complete killing of planktonic cells and biofilms of Enterococcus faecalis within 5 minutes and 10 minutes respectively).
Conclusions: Our results indicate the potential to exploit iron oxide nanoparticles with intrinsic catalytic activity as a potent alternative or adjunctive antimicrobial agent for the treatment of bacterial biofilms associated with endodontic infections.