Search

Abstract The number of biosafety evaluation studies of nanoparticles (NPs) using different biological models is increasing with the rapid development of nanotechnology. Thus far, nematode Caenorhabditis elegans (C. elegans), as a complete model organism, has become an important in vivo alternative assay system to assess the risk of NPs, especially at the environmental level. According to results of qualitative and quantitative analyses, it can be concluded that studies of nanoscientific research using C. elegans is persistently growing. However, the comprehensive conclusion and analysis of toxic effects of NPs in C. elegans are limited and chaotic. This review focused on the effects, especially sublethal ones, induced by NPs in C. elegans , including the development, intestinal function, immune response, neuronal function, and reproduction, as well as the underlying mechanisms of NPs causing these effects, including oxidative stress and alterations of several signaling pathways. Furthermore, we presented some factors that influence the toxic effects of NPs in C. elegans. The advantages and limitations of using nematodes in the nanotoxicology study were also discussed. Finally, we predicted that the application of C. elegans to assess long-term impacts of metal oxide NPs in the ecosystem would become a vital part of the nanoscientific research field, which provided an insight for further study. Graphical abstract Image 1 Highlights • The publication related to the nanoscientific research using C. elegans is increasing in recent years. • The toxicity of NPs can be assessed in C. elegans through endpoints of biological functions and molecular markers. • Factors of both NPs physicochemical properties and C. elegans cultivation environment can influence the toxicity of NPs. • There are several advantages and drawbacks of C. elegans in nanotoxicology studies. [ABSTRACT FROM AUTHOR]

Along with the rapidly increasing applications of nitrogen-doped graphene quantum dots (N-GQDs) in the field of biomedicine, the exposure of N-GQDs undoubtedly pose a risk to the health of human beings, especially in the nervous system. In view of the lack of data from in vivo studies, this study used the nematode Caenorhabditis elegans (C. elegans), which has become a valuable animal model in nanotoxicological studies due to its multiple advantages, to undertake a bio-safety assessment of N-GQDs in the nervous system with the assistance of a deep learning model. The findings suggested that accumulated N-GQDs in the nematodes' bodies damaged their normal behavior in a dose- and time-dependent manner, and the impairments of the nervous system were obviously severe when the exposure dosages were above 100 μg/mL. When assessing the morphological changes of neurons caused by N-GQDs, a quantitative image-based analysis based on a deep neural network algorithm (YOLACT) was used because traditional image-based analysis is labor-intensive and limited to qualitative evaluation. The quantitative results indicated that N-GQDs damaged dopaminergic and glutamatergic neurons, which are involved in the neurotoxic effects of N-GQDs in the nematode C. elegans. This study not only suggests a fast and economic C. elegans model to undertake the risk assessment of nanomaterials in the nervous system, but also provides a valuable deep learning approach to quantitatively track subtle morphological changes of neurons at an unbiased level in a nanotoxicological study using C. elegans. [ABSTRACT FROM AUTHOR]