Toxicity Assessment Of Nanomaterials Research Articles

Based on the Nano-QSAR model: Prediction of factors influencing damage to C. elegans caused by metal oxide nanomaterials and validation of toxic effects

Analysis of structure-activity relationships (SARs) at nano–bio interfaces is important for guiding the safe design of nanomaterials and the assessment of potential toxicity. Metal oxide (MeOx) nanomaterials are used in a wide range of applications due to their unique mechanical stability and optoelectronic properties. However, the increasing number of biosafety issues and exposure risks have led to a focus on the safety assessment of nanomaterials. Considering the wide range of MeOx nanomaterials and their various different properties, it is difficult to assess individual toxicities using traditional toxicological analyses. Nanometric quantitative structure–activity relationship (nano-QSAR) analysis offers new ideas for developing nano-informatics modeling. In this study, six physicochemical properties of 16 MeOx nanomaterials from different classes (MeO, MeO2, MeO3 and Me2O3) were standardized and ordered according to their weights based on the nano-QSAR analysis strategy to construct quasi-SMILES descriptors that can accurately measure the material property characteristics and finally achieve the prediction of material structural properties and bio-toxic effects. The modeling results suggest that the Zeta potential and the metal cation charge number of MeOx nanomaterials may be important parameters affecting the toxicity of associated materials. To further clarify the quantitative relationship between these two important properties and the final toxic endpoint, as well as the possible mechanism of damage, the toxicity mechanisms of four representative MeOx nanomaterials were further analyzed in this study using Caenorhabditis elegans. The results ultimately confirm that nanomaterials with higher absolute Zeta potential or higher metal cation charge may have the greater oxidative capacity and can cause more severe oxidative damage and free radical accumulation in nematodes via smaller uptake levels at the same survival rate. This study highlights the important influence of structural properties of MeOx nanomaterials on toxicity outcomes. Moreover, our data suggest that oxidative stress, an important mechanism of MeOx nanomaterial-induced damage, can be controlled by the material's Zeta potential and cationic charge number. This provides a novel strategy for the safe design and toxicity assessment of nanomaterials in the future.

Recent advances in nanomaterials based sustainable approaches for mitigation of emerging organic pollutants

Emerging organic pollutants (EOPs) are a category of pollutants that are relatively new to the environment and recently garnered a lot of attention. The majority of EOPs includes endocrine-disrupting chemicals (EDCs), antibiotic resistance genes (ARGs), pesticides, dyes and pharmaceutical and personal care products (PPCPs). Exposure to contaminated water has been linked to an increase in incidences of malnutrition, intrauterine growth retardation, respiratory illnesses, liver malfunctions, eye and skin diseases, and fatalities. Consequently, there is a critical need for wastewater remediation technologies which are effective, reliable, and economical. Conventional wastewater treatment methods have several shortcomings that can be addressed with the help of nanotechnology. Unique characteristics of nanomaterials (NMs) make them intriguing and efficient alternative in wastewater treatment strategies. This review emphasis on the occurrence of divers emerging organic pollutants (EOPs) in water and their effective elimination via different NMs based methods with in-depth mechanisms. Furthermore, it also delves the toxicity assessment of NMs and critical challenges, which are crucial steps for practical implementations.

Effect of titanium dioxide nanoparticles on the accumulation and distribution of arsenate in Daphnia magna in the presence of an algal food.

The impact of titanium dioxide nanoparticles (nano-TiO2) on the bioavailability of metals in aquatic filter-feeding organisms has rarely been investigated, especially in the presence of algae as a food source. In this study, we quantified the accumulation and subcellular distribution of arsenate (AsV) in Daphnia magna in the presence of nano-TiO2 and a green alga (Scenedesmus obliquus) food source. Results showed that S. obliquus significantly increased the accumulation of total arsenic (As) and titanium (Ti) in D. magna. The presence of this food source increased As in metal-sensitive fractions (MSF) and as biologically detoxified metals (BDM), while it decreased Ti levels in MSF but increased levels as BDM. The difference in the subcellular distribution of As and Ti demonstrates the dissociation of As from nano-TiO2 during digestion at subcellular partitioning irrespective of food availability. In turn, the presence of algae was shown to increase metal-based toxicity in D. magna due to the transfer of As from BMD to MSF. Furthermore, S. obliquus significantly increased the concentration of As and Ti in soluble fractions, indicating that As and nano-TiO2 ingested by D. magna could be transferred more readily to their predators in the presence of S. obliquus. Our study shows the potential of algae to increase the toxicity and biomagnification of AsV. Furthermore, it highlights food as an important factor in the toxicity assessment of nanomaterials and co-existing pollutants.

Toxicity assessment of nanomaterials: methods and challenges

The increasing use of nanomaterials in consumer and industrial products has aroused global concern regarding their fate in biological systems, resulting in a demand for parallel risk assessment. A number of studies on the effects of nanoparticles in in vitro and in vivo systems have been published. However, there is still a need for further studies that conclusively establish their safety/toxicity, due to the many experimental challenges and issues encountered when assessing the toxicity of nanomaterials. Most of the methods used for toxicity assessment were designed and standardized with chemical toxicology in mind. However, nanoparticles display several unique physicochemical properties that can interfere with or pose challenges to classical toxicity assays. Recently, some new methods and modified versions of pre-existing methods have been developed for assessing the toxicity of nanomaterials. This review is an attempt to highlight some important methods employed in nanomaterial toxicology and to provide a critical analysis of the major issues/challenges faced in this emerging field.