antimicrobial photothermal treatment of pseudomonas aeruginosa by a carbon nanoparticlespolypyrrole nanocomposite

Background: nowadays, it is needed to explore new routes to treat infectious bacterial pathogens due to prevalence of antibioticresistant bacteria. antimicrobial photothermal therapy (ptt), as a new strategy, eradicates pathogenic bacteria.objective: in this study, the antimicrobial effects of a carbon nanoparticlespolypyrrole nanocomposite (cppy) upon laser irradiation were investigated to destroy the pathogenic gramnegative pseudomonas aeruginosa. material and methods: in this experimental study, the bacterial cells were incubated with 50, 100 and 250 µg ml1 concentrations of cppy and irradiated with a 808nm laser at two power densities of 0.5 and 1.0 w cm2. cfu numbers were counted for the irradiated cells, and compared to an untreated sample (kept in dark). to explore the antibacterial properties and mechanism(s) of cppy, temperature increment, reactive oxygen species formation, and protein and dna leakages were evaluated. field emission scanning electron microscopy was also employed to investigate morphological changes in the bacterial cell structures. results: the results showed that following cppy attachment to the bacteria surface, irradiation of nearinfrared light resulted in a significant decrement in the bacterial cell viability due to photothermal lysis. slightly increase in protein leakage and significantly increase intracellular reactive oxygen species (ros) were observed in the bacteria upon treating with cppy. conclusion: photoablation strategy is a new minimally invasive and inexpensive method without overdose risk manner for combat with bacteria.