Photodynamic Antibacterial Chemotherapy (PACT) Against Staphylococcus aureus and Escherichia coli Using Gold Nanoparticles and LED's Irradiation

Abstract

Gold nanoparticles synthesized through sodium citrate (A-AuNPs) and sodium borohydrade (B-AuNPs) reduction of Au3+ and a photochemically initiated method (C-AuNPs) were tested for possible application in Photodynamic Antibacterial Chemotherapy. None of them presented inhibitory activity against bacterial suspensions in dark conditions using the cylinders inhibition method; however, a total inhibition of Staphylococcus aureus ATCC 29213 and an extended-spectrum beta-lactamases-producing Escherichia coli ATCC 25922 growth were observed when incubated with 2 mM B-AuNPs and irradiated with LEDs at 525 nm for 12 h. Characterization of the interaction between S.aureus and B-AuNPs was demonstrated through an optimized procedure for TEM. These results probe that B-AuNPs have a good potential as photosensitizers for PACT.