Fluorescence monitoring of endogenous microRNA (miRNA or miR) activity related to neuronal development using nano-sized materials provides crucial information on miRNA expression patterns in a noninvasive manner. In this study, we report a new method to monitor intracellular miRNA124a using quantum dot-based molecular beacon (R9-QD-miR124a beacon). The R9-QD-miR124a beacon was constructed using QDs and two probes, miR124a-targeting oligomer and arginine rich cell-penetrating peptide (R9 peptide).

The apoptotic and genotoxic potential of titanium dioxide nanoparticles (TiO2NPs) were evaluated in hemocyte cells of freshwater snail Lymnea luteola L. Before evaluation of the toxic potential, mean size of the TiO2NPswas determined using a transmission electron microscopyand dynamic light scattering. In this study, L. luteola wereexposed to different concentrations of TiO2NPs (28, 56, and84 lg/ml) over 96 h.

Copper oxide nanoparticles (CuONP) are among the most widely used engineered nanoparticles and thus likely to permate the environment predominantly in sediments. The present study was designed to examine the adverse effects of CuONP in freshwater snail Lymnea luteola L. (L. luteola) exposed for 5 days. Induction of oxidative stress in digestive gland was evidenced by a decrease in reduced glutathione (GSH) levels, and activities of glutathione peroxidase (GPx) and glutathione-Stransferase (GST) whereas lipid peroxidation levels were increased at CuONP 7 or 21 mg/L.

Silver nanoparticles are increasingly used in various products, due to their antibacterial properties. Despite its wide spread use, only little information on possible adverse health effects exists. Therefore, the aim of this study was to assess the toxic potential of silver nanoparticles (<100 nm) in human lung epithelial (A549) cells and the underlying mechanism of its cellular toxicity. Silver nanoparticles induced dose and time-dependent cytotoxicity in A549 cells demonstrated by MTT and LDH assays.

Extensive applications of cerium oxide (CeO2) nanoparticles require a better understanding of their possible effects on human health. However, data demonstrating the effect of CeO2 nanoparticles on the human skin melanoma cell remain scanty. In the current study, we determined the mechanism through which CeO2 nanoparticles (APS\25 nm) induce toxicity in human skin melanoma cells (A375). The MTT [3-(4,5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide] and neutral red uptake assays showed concentration and time-dependent cytotoxicity of CeO2 nanoparticles in A375 cells.

The extensive production and wide application of carbon nanotubes have made investigations of its toxic potentials necessary. In the present study, we explored the underlying mechanism through which multi-walled carbon nanotubes (MWCNTs) induce toxicity in mouse fibroblast cells (L929). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and neutral red uptake viability assays were used to examine mechanisms of cytotoxicity. Dose and time-dependent cytotoxicity was observed in L929 cells.

Dimethoate is one of the organophosphate insecticides widely used in agriculture throughout the world and is an inhibitor of cholinesterase in animals. The objective of the present study was to detect oxidative stress and DNA damage induced by dimethoate in the freshwater fish Channa punctatus (C. punctatus). The LC50-96 h value of technical grade dimethoate was estimated at 19.10 μg L-1 in a semi-static system and, on the basis of the LC50 value, three concentrations were determined.

Alumina nanoparticles (Al2O3NPs) are gradually used in various areas, including nanomedicine, biosensors, and electronics. The current study aimed to explore the DNA damage and cytotoxicity due to Al2O3NPs on human hepatocarcinoma cells (HepG2). The MTT and neutral red uptake assays showed that Al2O3NPs induce significant cell death in a dose- and time-dependent manner. However, Al2O3NPs induced significant intracellular reactive oxygen species production and elevated lipid peroxidation and superoxide dismutase levels in the HepG2 cells.