IADR Abstract Archives
On-demand metal oxide nanozymes eradicate bacterial biofilm
Objectives: Biofilms are complex entities that are remarkably difficult to eradicate. Nanozymes are promising materials that trigger the conversion of hydrogen peroxide (H2O2) to superoxide radicals, resulting in excellent antibacterial activity. Copper oxide (CuO) shows intrinsic peroxidase enzyme-mimic activity. However, an external supply of H2O2 is not a clinically feasible approach, requiring alternative peroxidase-mimic substrates. Furthermore, the effect of CuO nanozymes on biofilms remains unknown and no ‘smart’ antimicrobial systems based on CuO nanozymes have been developed to date. To address this unmet need, this study was designed to (1) synthesize and characterize CuO nanoparticles, and (2) investigate the antimicrobial and antibiofilm activity of CuO in combination with a biocompatible peroxidase-mimic substrate in the presence and absence of external stimuli.
Methods: The CuO was synthesized using a facile solution-based approach. A suite of materials characterization techniques was employed to understand the morphology, surface characteristics, size, and optical properties of CuO. The ability of the CuO alone and in combination with the peroxidase-mimic substrate to rapidly kill planktonic and biofilm forms of a key pathogen, Enterococcus faecalis, were evaluated in the presence and absence of external stimuli.
Results: CuO and the peroxidase-mimic substrate did not kill E. faecalis at concentrations of 10 ppm and 50 mM respectively. However, sub-lethal concentrations CuO and the mimic were synergistically able to eliminate both planktonic and preformed biofilms forms of E. faecalis within 5 mins of external stimulus application (P<0.05). On the other hand, no significant inhibition of E. faecalis was observed against both planktonic and biofilm forms of E. faecalis (P>0.05) in the absence of such external trigger.
Conclusions: This study shows new insights into the on-demand synergistic antibiofilm activity of CuO nanoparticles and a peroxidase-mimic substrate.
Methods: The CuO was synthesized using a facile solution-based approach. A suite of materials characterization techniques was employed to understand the morphology, surface characteristics, size, and optical properties of CuO. The ability of the CuO alone and in combination with the peroxidase-mimic substrate to rapidly kill planktonic and biofilm forms of a key pathogen, Enterococcus faecalis, were evaluated in the presence and absence of external stimuli.
Results: CuO and the peroxidase-mimic substrate did not kill E. faecalis at concentrations of 10 ppm and 50 mM respectively. However, sub-lethal concentrations CuO and the mimic were synergistically able to eliminate both planktonic and preformed biofilms forms of E. faecalis within 5 mins of external stimulus application (P<0.05). On the other hand, no significant inhibition of E. faecalis was observed against both planktonic and biofilm forms of E. faecalis (P>0.05) in the absence of such external trigger.
Conclusions: This study shows new insights into the on-demand synergistic antibiofilm activity of CuO nanoparticles and a peroxidase-mimic substrate.