We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Shape-Dependent Toxicity of Silver Nanoparticles on Freshwater Cnidarians
Summary
Researchers investigated how the shape of silver nanoparticles affects their toxicity to freshwater Hydra vulgaris, finding that triangular nanoplates were significantly more toxic than spherical or rod-shaped particles, challenging the assumption that toxicity is shape-independent.
Silver nanoparticles (AgNPs) are increasingly used in various consumer products, leading to their inadvertent release in aquatic ecosystems. The toxicity of AgNPs could be associated with the leaching of ionic Ag but also with the size, shape and surface properties. The purpose of this study was to test the null hypothesis that toxicity of AgNPs was independent of shape in the invertebrate Hydra vulgaris. The hydranths were exposed to increasing concentrations of ionic Ag and AgNPs of three different shapes (spherical, cubic and prismatic) with the same size and coating (polyvinylpyrrolidone). The data revealed that between 68% and 75% of total Ag remained in solution after the 96 h exposure period, while 85−90% of ionic Ag remained in solution. The 96 h lethal concentration (LC50) was lower with ionic (4 µg/L) and spherical AgNPs (56 µg/L), based on irreversible morphological changes such as loss of tentacles and body disintegration. Cubic and prismatic AgNPs were not toxic at a concentration of <100 µg/L. The sublethal toxicity was also determined at 96 h based on characteristic morphological changes (clubbed and/or shortened tentacles) and showed the following toxicity: ionic (2.6 µg/L), spherical (22 µg/L) and prismatic (32.5 µg/L) AgNPs. The nanocube was not toxic at this level. The data indicated that toxicity was shape-dependent where nanoparticles with a low aspect ratio in addition to high circularity and elongation properties were more toxic at both the lethal and sublethal levels. In conclusion, the shape of AgNPs could influence toxicity and warrants further research to better understand the mechanisms of action at play.
Sign in to start a discussion.
More Papers Like This
Sensitivity of Hydra vulgaris to Nanosilver for Environmental Applications
Researchers tested a novel citrate and L-cysteine functionalized silver nanoparticle formulation against freshwater Hydra vulgaris, characterizing its environmental safety and finding that the nanoparticles caused dose-dependent toxicity, providing a useful benchmark for assessing nanomaterial risks in aquatic ecosystems.
Impacts of Differentially Shaped Silver Nanoparticles with Increasingly Complex Hydrophobic Thiol Surface Coatings in Small-Scale Laboratory Microcosms
Researchers tested how differently shaped silver nanoparticles with various surface coatings affected small ecosystems containing algae, bacteria, crustaceans, and fish embryos. They found that both particle shape and surface chemistry influenced how toxic the nanoparticles were to different organisms. The study suggests that the physical characteristics of engineered nanoparticles play an important role in determining their environmental impact.
Polymethylmethacrylate nanoplastics effects on the freshwater cnidarian Hydra viridissima
Polymethylmethacrylate nanoplastics caused morphological damage and slowed regeneration in the freshwater organism Hydra viridissima, though feeding rates were not significantly affected at most concentrations. The results establish Hydra as a useful model for testing nanoplastic toxicity in freshwater ecosystems.
Detection, biophysical effects, and toxicity of polystyrene nanoparticles to the cnidarian Hydra attenuata
Researchers exposed the freshwater cnidarian Hydra attenuata to 50- and 100-nm polystyrene nanoparticles and found size-dependent bioaccumulation, morphological damage, lipid peroxidation, and intracellular liquid crystal formation — with 100-nm particles more toxic per particle count, suggesting that lipid mobilization and organized intracellular structures may represent a novel nanoplastic toxicity mechanism in simple aquatic animals.
Sublethal Toxicity and Gene Expression Changes in Hydra vulgaris Exposed to Polyethylene and Polypropylene Nanoparticles
Researchers exposed the freshwater cnidarian Hydra vulgaris to polystyrene nanoplastics over an extended period, measuring sublethal toxicity endpoints and gene expression changes to understand the chronic effects of nanoplastic exposure on a simple but ecologically relevant aquatic animal.