Neurobehavior and neuron damage following prolonged exposure of silver nanoparticles with/without polyvinylpyrrolidone coating in Caenorhabditis elegans

Abstract

Silver nanoparticles (AgNPs) have become widespread in the environment with increasing industrial applications. But the studies about their potential health risks are far from enough, especially in neurotoxic effects. This study aimed to investigate the neurotoxic effects of longer‐term exposure (prolonged exposure for 48 h and chronic exposure for 6 days) of 20nm AgNPs with/without polyvinylpyrrolidone (PVP) coating at low concentrations (0.01–10 mg·L−1) to Caenorhabditis elegans. The results suggested that exposure to AgNPs induced damage to nematode survival, with the longest and relative average life span reduced. Exposure to AgNPs caused neurotoxicity on locomotion behaviors (head thrashes, body bends, pharyngeal pumping frequency, and defecation interval) and sensory perception behaviors (chemotaxis assay and thermotaxis assay), as well as impaired dopaminergic, GABAergic, and cholinergic neurons, except for glutamatergic, based on the alters fluorescence intensity, in a dose‐ and time‐dependent manner. Further investigations suggested that the low‐dose AgNPs (0.01–0.1 mg·L−1) exposure raises receptors of GABAergic and dopamine in C. elegans at the genetic level, whereas opposite results were observed at higher doses (1–10 mg·L−1), which implied that AgNPs could cause neurotoxicity by impairing neurotransmitter delivery. The PVP‐AgNPs could cause a higher fatality rate and neurotoxicity at the same dose. Notably, AgNPs did not cause any deleterious effect on nematodes at the lowest dose of 0.01 mg·L−1. In general, these results suggested that AgNPs possess the neurotoxic potential in C. elegans and provided useful information to understand the neurotoxicity of AgNPs, which would offer an inspiring perspective on the safe application.

Silver nanoparticles enhance the efficacy of aminoglycosides against antibiotic-resistant bacteria

“…To evaluate the effect of AgNPs on C. elegans motility, worms were age-synchronized and plated for 72 h on NGM containing AgNPs and dead E. coli OP50 as a food source. We performed a thrashing assay, a commonly used physiological assessment of neuromuscular function ( Brignull et al, 2006 ; Contreras et al, 2014 ; Zhang et al, 2021 ). The assay is performed by counting the number of body bends the worm performs in a 30-s interval when placed in a drop of liquid.…”

Neurotoxicity Evaluation of Nanomaterials Using C. elegans: Survival, Locomotion Behaviors, and Oxidative Stress

“…Li, Yu, Wu, Tang, & Wang, 2013;T. Wu, He, et al, 2015;Zhang et al, 2021). Similarly, impairments of various neurons (e.g., AFD sensory neurons, RME motor neurons, and dopaminergic neurons) have been observed in response to graphene-based nanomaterials, silver nanoparticles, copper oxide nanoparticles, and cadmium telluride quantum dots (Kim et al, 2020;Mashock et al, 2016;Piechulek & von Mikecz, 2018;Zhao, Wang, Wu, Li, & Wang, 2015).…”

“…For instance, exposure to graphene oxide nanomaterials and polystyrene nanoparticles have been shown to affect survival or lifespan in C. elegans (Kim, Eom, Choi, Hong, & Choi, 2020; Shang et al., 2021). In addition, induction of oxidative stress and generation of reactive oxygen species have been reported in response to graphene‐based nanomaterials, cadmium telluride quantum dots, multi‐walled carbon nanotubes, TiO 2 nanoparticles, polystyrene nanoparticles, and silver nanoparticles (Kim et al., 2020; Shang et al., 2021; Q. Wu, Li, et al., 2013; Q. Wu, Wang, et al., 2012; T. Wu, He, et al., 2015; Zhang et al., 2021). Moreover, graphene‐based nanomaterials, cadmium telluride quantum dots, silver nanoparticles, and aluminon nanoparticles have been shown to decrease the number of neurotransmitters and receptors (Kim et al., 2020; Y. Li, Yu, Wu, Tang, & Wang, 2013; T. Wu, He, et al., 2015; Zhang et al., 2021).…”

“…Wu, Wang, et al, 2012;T. Wu, He, et al, 2015;Zhang et al, 2021). Moreover, graphene-based nanomaterials, cadmium telluride quantum dots, silver nanoparticles, and aluminon nanoparticles have been shown to decrease the number of neurotransmitters and receptors (Kim et al, 2020;Y.…”

Long-term effects of silver nanoparticles (NM-300K) and soil amendments on soil respiration and mesofauna in a semi-field experiment

“…Adam et al (2018) 11 showed that among all produced AgNPs, 39-45% pristine Ag (Ag) ended up in landfills, while 15-23% were released to surface water. Various studies on AgNP toxicity towards soil organisms demonstrated negative effects on reproduction, survival and growth of nematodes (Caenorhabditis elegans), 12 earthworms (Pheretima guillemi and Eisenia fetida), 13,14 enchytraeids (Enchytraeus crypticus), 15 Collembola (Folsomia candida), [16][17][18] and the soil microbiome. 19 Efforts to reduce the risks of AgNPs are increasing.…”