, 2002, Shih et al., 2004 and Li and Lim, 2007). In HepG2, cadmium has been shown to cause apoptosis learn more via both extrinsic and intrinsic pathways ( Oh and Lim, 2006). Similarly, ROS alone have also been shown to cause apoptosis via both pathways ( Simon et al., 2000). In this study, CdCl2 was also shown to cause similar effects on the apoptotic biomarkers of both pathways, but the effects were less pronounced compared to that of CdTe-QDs, suggesting that the effects of CdTe-QDs possibly involve
both cadmium and ROS generated from these NPs. Our findings support the suggestions from recent studies on the mechanisms of cadmium-based QD-induced toxicity in different cell lines and in an invertebrate model organism that QD treatments resulted in more severe toxic effects than cadmium at the same concentration, suggesting that the QD effects were not only from the release of Cd2+ ions but also from the properties of the NPs and ROS generated from them ( Li et al., 2009, Chen et al., 2012 and Ambrosone et al., 2012). In conclusion, the present study investigated the mechanism of toxic effects
caused by CdTe-QDs in HepG2 cells and revealed that CdTe-QDs caused cytotoxicity in these Ribociclib manufacturer cells by inducing oxidative stress leading to apoptosis. Oxidative stress induced by CdTe-QDs was evidenced by the increase in ROS production and the interference of these NPs on the antioxidant defenses in test cells. CdTe-QDs caused apoptosis in test cells via both extrinsic Pembrolizumab order and intrinsic pathways. Even though the release of Cd2+ from CdTe-QDs was not measured in this study,
treatments of cells with equivalent cadmium concentrations (in the form of CdCl2) were conducted for comparative purposes. Since the effects of Cd-QDs appeared similar or greater to those of CdCl2, it was postulated that the toxicity of CdTe-QDs arises from more than one factor, including cadmium effects, ROS generation and the intrinsic nano-scale properties of CdTe-QDs. The study provides valuable information for understanding the toxicity of CdTe-QDs which is important for safety evaluation of the nanoparticles for future biomedical applications. None. The authors thank Dr. Sabina Halappanavar, Dr. Hongyan Dong and Dr. Vern Seligy for reviewing the manuscript. This work was supported by Canadian Regulatory System for Biotechnology and Chemicals Management Plan Monitoring and Surveillance funding. “
“Depleted uranium (DU) is the residue that remains after the refining and enriching of 235U from natural uranium; the content of 235U is usually 0.2–0.3%. Due to its high penetrability and low price as a raw material, DU has been widely used in counterweights, radiation-protective clothing, and military activities (serving as an armour material and an ammunition component) (Bleise et al., 2003).