No abstract

The use of nanoparticles - particles that range in size from 1 to 100 nm - has become increasingly prevalent in recent years, bringing with it a variety of potential toxic effects. Zebrafish embryos were exposed during the 3 day postfertilization period to gold nanospheres (GNSs), gold nanorods (GNRs), GNRs coated with polystyrene sulphate (PSS-GNRs) and GNRs coated with both PSS and polyallamine hydrochloride (PAH-PSS-GNRs). All nanorods were stabilized with cetyltrimethylammonium bromide. GNSs were the least toxic of the nanoparticles studied, with exposure resulting in no significant changes in mortality, hatching or heart rate. Exposure to GNRs and PSS-GNRs resulted in significant increases in mortality and significant decreases in hatching and heart rate. Treatment with GNRs caused significant changes in the expression of a variety of oxidative stress genes. The toxic effects of GNRs were ameliorated by coating them with PSS and, to a more marked extent, with a double coating of PSS and polyallamine hydrochloride.

Micro-pollutants in aquatic environment are an emerging challenge to the human health and ecosystems. This study was to investigate the acute toxicity before and after ferrate(VI) treatment for four pharmaceuticals (simvastatin, ivermectin, fluoxetine and oxytetracycline) at concentrations of 10 and 100 μg/L, respectively. Zebrafish animal model and Vibrio fischeri luminescent test were employed to achieve the study targets. It is the first effort using the stated methods to assess toxicity of the selected pharmaceuticals before and after ferrate(VI) treatment when biochemical responses of catalase (CAT), tumour necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β) and B-cell lymphoma 2 (Bcl-2) were assessed in the zebrafish model. The results firstly revealed a significant change in the gene expression of CAT (p<0.001), TNF-α SOD 1 (p<0.01), and Bcl-2 (p<0.05) for simvastatin at low concentrations, which exhibited high toxicity in comparison with other pharmaceuticals.Ferrate(VI) treatment significantly reduced the toxicity of simvastatin by partially removing it during the treatment process and ferrate(VI) itself did not produce additional toxicity in the effluent.

The cover image, by Srinath Patibandla et al., is based on the Research Article Comparative analysis of the toxicity of gold nanoparticles in zebrafish, https://doi.org/10.1002/jat.3628.