Today, the emergence and spread of antibiotic-resistant strains of bacteria have become a major challenge to public health. this causes researchers to pay attention to the non-antibiotic treatment of infections and other diseases caused by bacteria. in other hand, nowadays most of scienticts interested in using nano carriers for therapeutic applications. nano carreiers have more cells’s attraction, higher biocompatibility and higher selectivity in target cells. among nano carreiers, gold nanoparticles have unique properties such as neutral, stable and connection to drug molecules.this study is about investigating the toxicity of different concentrations of pegylated gold nanoparticles with size of 13nm and red led light on e.coli(ptcc1276) bacteria.the results of this study show that pegylated gold nanoparticles with red led light have high performance in gram negative bacteria with reducing the concentration.
Methods
In this study, the effects of different concentrations of pegylated gold nanoparticles with size 13 nm include (1,10,25,50,100,200,300 µg/ml ) of stuck solution with and without 15min radiation with using red leds as light source with intensity 30mw /cm2 to destroy e. coli ptcc 1276.
Results
Based on our results, it has been shown that these gold nanoparticlesare toxic for escherichia coli ptcc 1276 at concentrations above 1 µg/ml.the illumination of the bacteria during 15min also showed a 0.15log reduction of bacterial viability. in addition, according to our observations, the inactivation of escherichia coli ptcc 127 through simultaneous application of 1 µg/ml gold nanoparticles and coherent beams of the led to a 2.43log reduction of viability for 15 min exposure time. we also introduce different mechanisms in order to analysis the obtained results.
Conclusion
In this study, the light source used in these experiments arrangement by 48 red leds wavelength 630nm, it should be noted that the intensity of actions in these tests (30 milliwatts per square centimeter) are without heat and light effects and light only through the stimulation of gold nanoparticles exerts its effect. in fact, applying radiation to the bacterial suspension containing pegylated gold nanoparticles stimulate light-sensitive material triad is metastable excited state. as a result of these factors are highly reactive, reacts with components of biological structures causing their oxidation resulting in death was organism.
Keywords
Pegylated gold nanoparticles, led, e. coli, toxicity
