Distribution of silver in rats following 28 days of repeated oral exposure to silver nanoparticles or silver acetate
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Distribution of silver in rats following 28 days of repeated oral exposure to silver nanoparticles or silver acetate. / Loeschner, Katrin; Hadrup, Niels; Qvortrup, Klaus; Larsen, Agnete; Gao, Xueyun; Vogel, Ulla Birgitte; Mortensen, Alicja; Lam, Henrik Rye; Larsen, Erik Huusfeldt.
In: Particle and Fibre Toxicology, Vol. 8, 01.06.2011, p. 18.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Distribution of silver in rats following 28 days of repeated oral exposure to silver nanoparticles or silver acetate
AU - Loeschner, Katrin
AU - Hadrup, Niels
AU - Qvortrup, Klaus
AU - Larsen, Agnete
AU - Gao, Xueyun
AU - Vogel, Ulla Birgitte
AU - Mortensen, Alicja
AU - Lam, Henrik Rye
AU - Larsen, Erik Huusfeldt
PY - 2011/6/1
Y1 - 2011/6/1
N2 - Background: The study investigated the distribution of silver after 28 days repeated oral administration of silver nanoparticles (AgNPs) and silver acetate (AgAc) to rats. Oral administration is a relevant route of exposure because of the use of silver nanoparticles in products related to food and food contact materials. Results: AgNPs were synthesized with a size distribution of 14 ± 4 nm in diameter (90% of the nanoparticle volume) and stabilized in aqueous suspension by the polymer polyvinylpyrrolidone (PVP). The AgNPs remained stable throughout the duration of the 28-day oral toxicity study in rats. The organ distribution pattern of silver following administration of AgNPs and AgAc was similar. However the absolute silver concentrations in tissues were lower following oral exposure to AgNPs. This was in agreement with an indication of a higher fecal excretion following administration of AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG) staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM), nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. Conclusions: The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver granules containing selenium and sulfur in the intestinal wall of rats exposed to either of the silver forms suggests a common mechanism of their formation. Additional studies however, are needed to gain further insight into the underlying mechanisms of the granule formation, and to clarify whether AgNPs dissolve in the gastrointestinal
AB - Background: The study investigated the distribution of silver after 28 days repeated oral administration of silver nanoparticles (AgNPs) and silver acetate (AgAc) to rats. Oral administration is a relevant route of exposure because of the use of silver nanoparticles in products related to food and food contact materials. Results: AgNPs were synthesized with a size distribution of 14 ± 4 nm in diameter (90% of the nanoparticle volume) and stabilized in aqueous suspension by the polymer polyvinylpyrrolidone (PVP). The AgNPs remained stable throughout the duration of the 28-day oral toxicity study in rats. The organ distribution pattern of silver following administration of AgNPs and AgAc was similar. However the absolute silver concentrations in tissues were lower following oral exposure to AgNPs. This was in agreement with an indication of a higher fecal excretion following administration of AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG) staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM), nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. Conclusions: The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver granules containing selenium and sulfur in the intestinal wall of rats exposed to either of the silver forms suggests a common mechanism of their formation. Additional studies however, are needed to gain further insight into the underlying mechanisms of the granule formation, and to clarify whether AgNPs dissolve in the gastrointestinal
KW - Acetates
KW - Administration, Oral
KW - Animals
KW - Dose-Response Relationship, Drug
KW - Female
KW - Humans
KW - Ileum
KW - Materials Testing
KW - Metal Nanoparticles
KW - Particle Size
KW - Random Allocation
KW - Rats
KW - Rats, Wistar
KW - Silver
KW - Silver Compounds
KW - Tissue Distribution
U2 - 10.1186/1743-8977-8-18
DO - 10.1186/1743-8977-8-18
M3 - Journal article
C2 - 21631937
VL - 8
SP - 18
JO - Particle and Fibre Toxicology
JF - Particle and Fibre Toxicology
SN - 1743-8977
ER -
ID: 35165382