Acute and Chronic Toxicity Effects of Silver Nanoparticles (NPs) on Drosophila melanogaster

Abstract

The use of nanoscaled materials is rapidly increasing, however, their possible ecotoxicological effects are still not precisely known. This work constitutes the first complex study focused on in vivo evaluation of the acute and chronic toxic effects and toxic limits of silver nanoparticles (NPs) on the eukaryotic organism Drosophila melanogaster. For the purpose of this study, silver NPs were prepared in the form of solid dispersion using microencapsulation method, where mannitol was used as an encapsulation agent. This newly prepared solid dispersion with a high concentration of silver NPs was exploited to prepare the standard Drosophila culture medium at a silver concentration range from 10 mg·L(-1) to 100 mg·L(-1) of Ag in the case of the acute toxicity testing and at a concentration equal to 5 mg·L(-1) in the case of the chronic toxicity testing. The acute toxic effect of silver NPs on Drosophila melanogaster was observed for the silver concentration equal to 20 mg·L(-1). At this silver concentration, 50% of the tested flies were unable to leave the pupae, and they did not finish their developmental cycle. Chronic toxicity of silver NPs was assessed by a long-term exposure of overall eight filial generations of Drosophila melanogaster to silver NPs. The long-term exposure to silver NPs influenced the fertility of Drosophila during the first three filial generations, nevertheless the fecundity of flies in subsequent generations consequently increased up to the level of the flies from the control sample due to the adaptability of flies to the silver NPs exposure.

Effects of carbon nanofiber on physiology of Drosophila

“…Especially, silver and gold nanoparticles show toxic effects on Drosophila fecundity and lifespan. [21][22][23]29 On the other hand, other studies reported that nanomaterials lack any significant adverse effects on Drosophila. For example, multi-walled carbon nanotubes at a concentration of 1,000 μg/g were shown to have no significant effect on developmental time or egg viability, 31 and single-walled carbon nanotubes at a concentration of 12-24 ppm during larval stage were reported to have no effect on pupal viability.…”

“…Following previous reports on nanomaterial supplementation to flies, 15,25,[29][30][31] CNFs were suspended in ethanol (0.5, 5% wt), and stock CNF solutions were added to normal CSY or sucrose-yeast (SY) fly media (10% sugar, 10% instant yeast, 0.2% methyl-4-hydroxybenzoate, 0.5% propionic acid, and 0.8% agar) to make food with a final CNF concentration of 100 or 1,000 μg/mL (0.01 or 0.1% wt). Parent flies reared on normal CSY media were transferred to CNF-containing CSY food in order to lay eggs for 24 hours.…”

Tissue-specific direct microtransfer of nanomaterials into Drosophila embryos as a versatile in vivo test bed for nanomaterial toxicity assessment

“…Nanotoxicity assessment studies have been previously conducted. Most of these studies use oral ingestion routes during third instar larval 32,[65][66][67][68] and adult stages 33,67,[69][70][71][72][73][74] to assess nanotoxicologic effects of several nanomaterials. Unfortunately, and because of the relatively small amounts of food intake during these stages, it is very difficult to accurately estimate actual amounts of ingested food.…”

“…In addition, several recent studies addressed the effect of silver nanoparticle toxicity, using oral ingestion as their administration routes, during third instar larva 32,68 and adult stages. 33,[69][70][71]73,74 If we consider that nanosilver has strong antimicrobial and antifungal properties, 80,81 together with the fact that Drosophila feeds mostly on microorganisms, particularly yeast, it is then possible to speculate that we may have confounding mortality effects arising from the unfavorable feeding conditions. Ingestion represents an important administration route, but more accurate screening tools are required.…”

Silver Nanoparticles in the Environment

“…Panacek et al 122 reported the acute and chronic toxicity effects of AgNPs on Drosophila. Acute toxicity assay indicated that half of the tested ies failed to nish their developmental cycle, and could not leave the pupae at a Ag concentration of 20 mg L…”