Insights into the Ecotoxicity of Silver Nanoparticles Transferred from Escherichia coli to Caenorhabditis elegans

Abstract

Previous studies have indicated that engineered nanomaterials can be transferred through the food chain. However, their potential ecotoxicity to the environment is not fully understood. Here, we systematically evaluated the physiological behavior and toxicity of polyvinylpyrrolidone (PVP)-coated silver nanoparticles (AgNPs) using a food chain model from Escherichia coli (E. coli) to Caenorhabditis elegans (C. elegans). Our results demonstrated that AgNPs accumulated in E. coli could be transferred to the C. elegans, and AgNPs were clearly distributed in the gut lumen, subcutaneous tissue and gonad. After being transferred to C. elegans through the food chain, the accumulated AgNPs caused serious toxicity to the higher trophic level (C. elegans), including effects on germ cell death, reproductive integrity and life span. Relative to larger particles (75 nm), small AgNPs (25 nm) more easily accumulated in the food chain and exhibited a stronger toxicity to the higher trophic level. More importantly, both the AgNPs that had accumulated in C. elegans through the food chain and the resulting impairment of germ cells could be transferred to the next generation, indicating that AgNP can cause genetic damage across generations. Our findings highlight that nanomaterials pose potential ecotoxicity to ecosystems via transport through the food chain.

Characterization of the silver thin films produced at different substrate temperatures

“…The results revealed that some of the small Ag NPs remained in the digestive lumen, subcutaneous tissue, and gonad. This verified that the Ag NPs uptake at the intracellular level and only small particles or partial aggregation of silver nanoparticles were detected in the cells, whereas larger aggregation was not internalized in E. coli [29][30][31] .…”

“…Moreover, the characteristic features of nanoparticles such as size, shape, density distribution have been demonstrated to affect the antibacterial activity of Ag NPs significantly, this could be attributed to a differential release of Ag + ions 10 . Previous researches in this field suggested that the effects of shapes and sizes prepared by wet chemical reduction methods or biosynthesis play a significant role in the antimicrobial nature of Ag NPs [11][12][13][14] . These methods have been devoted to controlling the size and shape of the Ag NPs, however, still, some obstacles such as the presence of colloidal stabilizers or impurities, the toxic solvents, and the sophisticated synthesis process to reduce or suppress the aggregation phenomenon in solution were detected [15][16][17] .…”

Materials and toxicological approaches to study metal and metal-oxide nanoparticles in the model organism Caenorhabditis elegans

“…These are a combination of nano-specific effects and, in the case of biodegradable particles, also ion-related effects. Data extracted from Ma et al , Liu et al ,[93] Luo et al ,[94] Yu et al ,[67] Levy et al ,[95] Soenen et al ,[96, 97] Sabella et al ,[98] Ma et al [24] and Polak et al . [49]…”

Multigenerational exposure of populations of Oppia nitens to zinc under pulse and continuous exposure scenarios

“…Teratogenesis results in physical deformations (Hovland et al 2000) and in some cases behavioral aberrations (Weis 2014) that manifest later in life. A generational transfer of silver nanoparticles (NPs) from the parent was detected in the unexposed F1 generation of C. elegans (Luo et al 2016). There can also be a direct maternal transfer of metals to other generations (Kim et al 2013;Schultz et al 2016).…”