Respective Effects Of Indium Tin Oxide And Ceria Nanoparticles On Scenedesmus Obliquus And Balb/c Mice

Nanoparticles are being used in various applications and, consequently, increasing amounts are predicted to be released into the environment where they can pose potential risks to living organisms. In order to avert such a situation, it is needful to study the toxicity of the mostly wide used nanoparticles since it is important to comprehend the biological fate and possible toxicity of nanoparticles for the successful use in daily life.Indium tin oxide nanoparticles (ITO NPs) and Ceria nanoparticles (CeO2 NPs) were chosen in this study because of their wide range in application. Additionally, CeO2 NPs were selected due to their likely beneficial and harmful effects on living organisms including humans. The toxicity of these nanoparticles was tested with the common biologic models. While Scenedesmus obliquus, the green algae known to be comparatively sensitive to many chemicals, were exposed to a series of ITO NPs concentrations (0,50,100,200 and 400 mg/L) for 21 days, Balb/c mice, the common biological model in animal experimentation, were treated with CeO2 NPs concentrations (0,100,200,400 and 800 mg/kg BW) by intragastric administration for 9 weeks. Superoxide dismutase (SOD), reduced glutathione (GSH) and free malondialdehyde (MDA) were measured in algae and mice (liver and kidney) every week and after exposure, respectively. In addition, algal cell count and photosynthetic pigment contents, and mice body weight were performed according to the respective exposure period.The results showed that ITO NPs concentrations ranging from 50 to 400 mg/L did not cause any significant changes in all the tested variables. CeO2 NPs concentrations of 100 mg/kg BW caused a no significant increase in SOD activity, indicating that CeO2 NPs may enhance the antioxidant defense at low concentrations. However, as the concentration increased (400 and 800 mg/kg BW), both SOD activities and GSH contents were significantly reduced in livers and kidneys in a concentration dependent manner although the mice body weight did not change. Additionally, MDA contents were increased, suggesting the possible occurrence of lipid peroxidation in both livers and kidneys.These results suggested that ITO NPs may exhibit harmless effects on Scenedesmus obliquus. However, there is a need of additional investigation to fully support this suggestion. To this end, research could be focused on the effects of elevated ITO concentrations and/or extended exposure period on Scenedesmus obliquus including its offsprings. Moreover, CeO2 NPs may exhibit toxic effects to mammalians through generation of oxidative stress. In the light of their growing use, particularly their promising uses in medicine for drug delivery, careful more research is necessary prior to a generalized use.This study contributes to an insight into how some nanoparticles may exhibit harmless effects to living organisms, while others may constitute a global concern in spite of their promising uses. In addition, it shows why people have to be careful when manipulating nanoparticles, especially Ceria Nanoparticles, during production, use and/or handling.