Enhancement of photo-bactericidal effect of tetrasulfonated hydroxyaluminum phthalocyanine on Pseudomonas aeruginosa

AbstractAt the present time, photodynamic inactivation (PDI) is receiving considerable interest for its potential as an antimicrobial therapy. The results of our study indicate that enhancement of the phototoxic effect onPseudomonas aeruginosa can be achieved by combination of tetrasulfonated hydroxyaluminum phthalocyanine (AlPcS4) and bimetallic gold/silver nanoparticles (Au/Ag-NPs) synthesized by the cell-free filtrate ofAureobasidium pullulans. The bimetallic nanoparticles were characterized by a number of techniques including UV-vis, XPS, TEM, and SEM-EDS to be 14  ± 3 nm spherical particles coated with proteins. The effect of diode lasers with the peak-power wavelengthʎ = 650 nm (output power of 10 and 40 mW; radiation intensity of 26 and 105 mW/cm2) in combination with the AlPcS4 and the bimetallic nanoparticles mixture on the viability ofP. aeruginosa rods was shown. Particularly high efficiency of killing bacterial cells was obtained for the light intensity of 105  mW/cm2, after 20, 30, and 40  min of irradiation corresponding to 126, 189, and 252  J/cm2 energy fluences. For AlPcS4+Au/Ag-NPs treatment, the viable count reduction were equal to 99.90, 99.96, and 99.975%, respectively. These results were significantly better than those accomplished for irradiated separated assays of AlPcS4 and Au/Ag-NPs.
Source: Lasers in Medical Science - Category: Laser Surgery Source Type: research