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Nowadays, developing countries have seen a reduction in male reproductive parameters, and it has been linked to the exposure of endocrine disrupting chemicals (EDCs), which are able to mimic or disrupt steroid hormone actions. Also, nanoparticles have shown effects on the male reproductive system, in particular the use of TiO2-NPs in drugs, cosmetics, and food as pigment additives, and, thanks to their small size (1–100 nm), provide themselves the opportunity to be internalized by the body and pass the blood–testis barrier (BTB). Therefore, TiO2-NPs can act on spermatogenesis and spermatozoa. In this study, we carried out an in vitro assay on human spermatozoa to evaluate the effects of TiO2-NPs at the concentrations of 500, 250, 100, and 50 ppm. Exposure did not statistically alter sperm parameters (e.g., motility and viability) but induced damage to sperm DNA and the expression of biomarkers by spermatozoa. This immunofluorescence investigation showed a positivity for biomarkers of stress (HSP70 and MTs) on the connecting piece of spermatozoa and also for sex hormone binding globulin (SHBG) biomarkers. The SHBG protein acts as a carrier of androgens and estrogens, regulating their bioavailability; therefore, its expression in the in vitro assay did not rule out the ability of TiO2-NPs to act as endocrine disruptors. [ABSTRACT FROM AUTHOR]

TiO2 and CeO2 NPs are widely used in the medical field, for drug administration, oncological therapies, disinfection or diagnostic imaging. To date, their effects on aquatic ecosystems and their impacts on human health are little known but several scientific evidences show how CeO2 NPs are able to store and release oxygen, giving them antioxidant activity against oxidative stress while TiO2 NPs seem to be responsible for cytotoxicity and genotoxicity. In this study, the effects of combined nanoparticles, brookite TiO2/CeO2 nanocomposites, on A. salina nauplii following acute exposure were evaluated. Although the cytotoxicity of nanoparticles is generally dose-dependent and time-dependent, in the following investigation, exposure to combined nanoparticles, brookite TiO2/CeO2 nanocomposites, in A. salina nauplii would appear not to have had a statistically significant negative impact on the viability of the specimens. One of the mechanisms by which NPs exert toxic effects is the induction of oxidative stress. In this study, an assessment of potential oxidative stress and apoptotic damage on exposed organisms was conducted through the use of the DCFH2DA probe and acridine orange. The results obtained suggest that although acute exposure to different concentrations of brookite TiO2/CeO2 nanocomposites did not have lethal effects, the positivity to DCFH2DA and acridine orange observed does not exclude potential sublethal effects. [ABSTRACT FROM AUTHOR]