AG/SIO2 CO - DOPED FULLERENE AS A NOVEL NANOSYSTEM FOR EFFICIENT PHOTODYNAMIC INACTIVATION OF PSEUDOMONAS AERUGINOSA BIOFILM

The 17 th International and Iranian Congress of Microbiology

23 till 25 August 2016، Tehran - Iran

Presentation Type: Speech
Abstract:

Backgroun d and Aim: Nanotechnology has made a significant contribution to Photodynamic inactivation (PDI), as one of the promising alternative treatments to combat biofilm. The effectiveness of PDI using fullerene nanoparticle (as a photosensitizer) can be improved by development   of   innovative   multifunctional   nanosystems.   Here   we   aimed   to   evaluate photodynamic inactivation of Pseudomonas aeruginosa biofilm using a novel nano - based photosensitizer (a hybrid nanosystem composed of silver, silica and fullerene).
Method s: Ag/SiO2 co - doped fullerene nanosystem was synthesized by chemical vapor deposition (CVD) method. 24 - h - old biofilms of P. aeruginosa were treated with the nanosystem for 10 min and subsequently exposed to white light from a light - emitting diode (LED) at f luence of 42.2 J/cm2. Appropriate controls were included. Biofilm metabolic activity was quantified by colorimetry with a tetrazolium reduction assay to measure live bacteria after the treatments. To determine   the   effect   of   PDI   on   P.  aeruginosa   biofilm   str ucture,   three - dimensional   (3D) morphology and surface of biofilm was investigated by atomic force microscopy (AFM).
Results: Ag/SiO2   co - doped   fullerene   nanosystem - mediated   PDI   significantly   reduced   the metabolic activity of biofilm of P. aeruginosa ( ∼ 100%). In the absence of light, the nanosystem did not significantly impair biofilm metabolic activity ( ∼ 3%). An analysis of the AFM topography 3D - images showed that Ag/SiO2 co - doped fullerene nanosystem - mediate PDI induced severe morphological and surface alter ations (loss of the typical cell morphology and increase in surface roughness, respectively) of biofilm.
Conclusion: In conclusion, Ag/SiO2 co - doped fullerene nanosystem - mediated PDI offer a new modality for fast and efficient destruction of P. aeruginosa biofilm, suggesting its potential use in chronic wound healing.