It is expected that the number and variety of engineered nanoparticles will increase rapidly over the next few years, and there is a need for new methods to quickly test the potential toxicity of these materials. Because experimental evaluation of the safety of chemicals is expensive and time-consuming, computational methods have been found to be efficient alternatives for predicting the potential toxicity and environmental impact of new nanomaterials before mass production. Here, we show that the quantitative structure-activity relationship (QSAR) method commonly used to predict the physicochemical properties of chemical compounds can be applied to predict the toxicity of various metal oxides. Based on experimental testing, we have developed a model to describe the cytotoxicity of 17 different types of metal oxide nanoparticles to bacteria Escherichia coli. The model reliably predicts the toxicity of all considered compounds, and the methodology is expected to provide guidance for the future design of safe nanomaterials.

Gold, in both nanoparticle (AuNPs) and ionic forms, has been studied for antibiotic activities. Some of the organic complexes of Au (I & III) ions are antibacterial. AuNPs are antifungal, but with conflicting results on their antibacterial activity. We summarized these publications and found that AuNPs are generally not bactericidal, or only weakly at high concentrations. However, the reason AuNPs appear to be bactericidal is possibly due to the bactericidal activity of co-existing chemicals not completely removed from AuNPs: gold ions, surface coating agents, and chemicals involved in the synthesis. AuNPs can also act as carriers or delivery vehicles of antibiotics, thus enhancing the bactericidal effect of the antibiotics.

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The datasets of this article present the experimental parameters resulting from the synthesis and characterization of graphene oxide (GO) using scanning and transmission electron microscopy (SEM, TEM) and spectrophotometric (FTIR, AFM, EDX) methods, and the assessment of its toxicological and endocrine-disrupting effects on the Japanese medaka fish by acute toxicity testing, and histopathological evaluations. These datasets support the article “Reproductive and Developmental Effects of Graphene Oxide on Japanese Medaka ( Oryzias latipes )". GO synthesis was performed following the modified Hummer's method. Its particle diameter and zeta potential were determined using Zeta Sizer Nano ZS analyzer, and characterized by SEM and TEM. After 5 min sonication in water, GO (25–200 µg/g) was injected intraperitoneally to the reproductively active male and female fish maintained as a breeding pair (one male, one female) in 500 mL balanced salt solution (BSS) in glass jars under standard laboratory conditions (25±1 °C; 16L:8D light cycle). The control fish were injected with water. The maximum volume of the injected material is 1 µL/10 mg body weight. To avoid movement, during injection the fish were briefly anesthetized in MS 222 (100 mg/L) and after injection transferred to BSS for recovery. LD 50 values of GO related to fish mortality were determined from the linear regression analysis using a software program. Reproductive activities (fecundity) were determined by daily collection of eggs 7 days before and 21 days after injection from a breeding pair and expressed as percent eggs laid every day post-injection relative to the average (mean of 7 days) eggs laid prior to injection. Developmental abnormalities of the embryos were assessed by culturing the collected fertilized eggs in ERM for a maximum period of 14 day-post fertilization (dpf). The fish that survived after 21days post-injection were sacrificed and the entire fish excluding post-anal tail were cut into three small pieces and fixed in 4% paraformaldehyde containing 0.05% Tween 20. Histopathological evaluations of gonads (ovary and testis), liver, and kidneys were made in 5 µm thick sections stained mainly on hematoxylin and eosin (HE) following the guidelines published by OECD. The Photomicrographs of the sections were made using Olympus B-max 40 microscope attached to a camera with Q-capture Pro 7 software or in Nikon Eclipse 50i microscope attached to Nikon DS-Fi1 camera. Four types of follicles in the stromal compartments of the ovary, perinucleolar (PNO), cortical alveolar (CAO), early vitellogenic (EVO) and late vitellogenic (LVO) were considered as differentiating, and the post ovulatory and atretic follicles were considered as degenerating follicles, and counted in an entire section made through four different regions (anterior, upper middle, lower middle, and anal) of the ovary. The follicular data were expressed as percent follicles (individual follicles or differentiating or degenerating) or as the ...

Due to their unique physicochemical properties, graphene-based nanoparticles (GPN) constitute one of the most promising types of nanomaterials used in biomedical research. GPN have been used as polymeric conduits for nerve regeneration, carriers for targeted drug delivery, and in the treatment of cancer via photo-thermal therapy. Moreover, they have been used as tracers to study the distribution of bioactive compounds used in healthcare. Due to their extensive use, GPN released into the environment would probably pose a threat to living organisms and ultimately to human health. Their accumulation in the aquatic environment creates problems to aquatic habitats as well as to food chains. Until now the potential toxic effects of GPN are not properly understood. Despite agglomeration and long persistence in the environment, GPN are able to cross the cellular barriers successfully, entered into the cells and able to interact with all most all the cellular sites including the plasma membrane, cytoplasmic organelles, and nucleus. Their interaction with DNA creates more potential threats to both the genome and epigenome. In this brief review, we focused on fish, mainly zebrafish (Danio rerio), as a potential target animal of GPN toxicity in the aquatic ecosystem.

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