Effects of Aqueous Exposure to Silver Nanoparticles of Different Sizes in Rainbow Trout

Abstract

Despite increasing application of silver nanoparticles (NPs) in industry and consumer products, there is still little known about their potential toxicity, particularly to organisms in aquatic environments. To investigate the fate and effects of silver NPs in fish, rainbow trout (Oncorhynchus mykiss) were exposed via the water to commercial silver particles of three nominal sizes: 10 nm (N(10)), 35 nm (N(35)), and 600-1600 nm (N(Bulk)), and to silver nitrate for 10 days. Uptake into the gills, liver, and kidneys was quantified by inductively coupled plasma-optical emission spectrometry, and levels of lipid peroxidation in gills, liver, and blood were determined by measurements of thiobarbituric acid reactive substances. Expression of a suite of genes, namely cyp1a2, cyp3a45, hsp70a, gpx, and g6pd, known to be involved in a range of toxicological response to xenobiotics was analyzed in the gills and liver using real-time PCR. Uptake of silver particles from the water into the tissues of exposed fish was low but nevertheless occurred for current estimated environmental exposures. Of the silver particles tested, N(10) were found to be the most highly concentrated within gill tissues and N(10) and N(Bulk) were the most highly concentrated in liver. There were no effects on lipid peroxidation in any of the tissues analyzed for any of the silver particles tested, and this is likely due to the low uptake rates. However, exposure to N(10) particles was found to induce expression of cyp1a2 in the gills, suggesting a possible increase in oxidative metabolism in this tissue.

In vitro and in vivo toxicity assessment of nanoparticles

“…The results demonstrated uptake of silver nanoparticles in liver, gills and kidney. The study also evidenced induced expression of cyp1a2 in the gills suggesting an increase in oxidative metabolism [187].…”

“…Silver nanoparticles are also known for genotoxicity and cytotoxicity in fish including accumulation in gill tissues and lysosomal destabilization in adult oysters. They are also known for adverse effects on oyster embryonic development, oxidative stress and expression of p53 protein in zebrafish [187,[199][200][201][202]. In another study conducted on zebrafish, it was observed that silver nanoparticles caused induction of apoptosis and oxidative stress in the liver.…”

Histopathological effects of waterborne silver nanoparticles and silver salt on the gills and liver of goldfish Carassius auratus

“…Cl -ions across the gills (Bury and Wood 1999). Ag can also cause tissue damage and accumulate in the liver tissue affecting the ability of fish to cope with low oxygen levels and inducing oxidative stress (Bilberg et al 2010a, b;Scown et al 2010).…”

Paradigms to assess the environmental impact of manufactured nanomaterials

“…During the past decade, nanomaterial fate and transport have become a major focus of research. Several review papers have highlighted the way environmental factors such as calcium concentration, pH, and the effects of organic ligands will alter the colloid behavior of nanomaterials and influence their ultimate fate [6][7][8][9][10].…”