Synthesis, characterization and in vivo evaluation of cadmium telluride quantum dots toxicity in mice by toxicometabolomics approach

Quantum dots (QDs) have widespread application in many fields such as medicine and electronics. The need for understanding the potentially harmful side effects of these materials becomes clear. In this study, the toxicity of cadmium telluride quantum dots (CdTe-QDs) and bulk Cd2+ has been investigated and compared by applying metabolomics methods. The datasets were 1H-NMR data from mice plasma which had been taken from four groups of mice in different time intervals. Then, the data were analyzed by applying chemometrics methods and the metabolites were found from Human Metabolome Database (HMDB). The results showed the significant change in the level of some metabolites especially estrogenic steroids in different groups with different amounts of received Cd. The findings also indicated that steroid hormone biosynthesis, lysine biosynthesis and taurine and hypotaurine metabolism are the most affected pathways by CdTe-QDs especially in estrogenic steroids. The over-representation analysis indicated that endoplasmic reticulum, gonads, and hepatocytes are most affected. Since the pattern of metabolite alteration of CdTe-QDs with equivalent Cd2+ was similar to those of CdCl2, it was postulated that beside Cd2+ effects, the toxicity of CdTe-QDs is associated with other factors.