Cytotoxic Responses and Potential Health Effects of nanosized ZnO on Tetrahymena thermophila

摘要

Several manufactured nanoparticles (NPs) are increasingly used in consumer goods. However, NPs may also have ecotoxicological effects after being discharged into the environment. Study of biological effects of NPs with organisms representing different trophic levels helps to understand mechanisms of uptake and following biological effects of NPs. In this study, the uptake of nano-ZnO by Tetrahymena thermophila was observed with transmission electron microscopy (TEM) and electron spin resonance (ESR). The viability of Tetrahymena thermophila and its dose-effect relationship at various concentrations of the NPs were measured. The result revealed that the model organism exposed to dispersed NPs solution have oxidative damages though lethal test did not give relationship data between survival and nanosuspension concentration in the laboratory condition. Among the NPs analyzed, nano-ZnO exhibited a dose-dependent growth stimulation to the Tetrahymena thermophila cells and others showed non-significant impact. The rapid proliferation of Tetrahymena thermophila cells was further confirmed by levels of the succinate dehydrogenase (SDH), protein content of control and treated groups.