Uptake of silver nanoparticles and toxicity to early life stages of Japanese medaka (Oryzias latipes): effect of coating materials.
Silver nanoparticles (AgNPs) with antimicrobial properties are perhaps the most deployed engineered nanomaterials in consumer products. Almost all AgNPs are coated with organic materials to enhance their dispersion in water. Contributions of coatings to the toxicity of NPs have received little attention. Studies using AgNPs with one of three different coating materials (citrate (Cit), gum arabic (GA), and polyvinylpyrrolidone (PVP)) showed significantly different toxicity. GA AgNP proved to be the most toxic, while PVP and Cit AgNP exhibited similar and lower toxicity. However, all AgNPs were about three to ten times less toxic than AgNO(3) when their toxicities were compared on a mass-concentration basis. Evidence for NP-specific toxicity was observed with longer time for initiation of toxicity and increased incidence of resultant spinal flexure of medaka exposed to AgNPs, compared to AgNO(3). Hyperspectral imaging of 6 μm paraffin sections of fish exposed to AgNPs revealed AgNPs and their aggregates in tissues of fish. Gill distribution was ubiquitous, while small amounts were found in other organs, including the liver and brain. AgNPs were observed regularly in the gut lumen, but rarely in mural elements and mesentery. These results suggest that while ingestion was common, gills were the principal sites of AgNP uptake. In conclusion, AgNPs is a source of toxic Ag ions, while itself contribute partially to its toxicity to fish, and which interact with skin surface and were taken up via the gills.
Nicholas School of the Environment and Center for the Environmental Implications of Nanotechnology, Duke University; Durham, NC 27708-0328, USA. kevin.kwok@duke.edu
Kevin W H
KW
Kwok
Melanie
M
Auffan
Appala R
AR
Badireddy
Clay M
CM
Nelson
Mark R
MR
Wiesner
Ashutosh
A
Chilkoti
Jie
J
Liu
Stella M
SM
Marinakos
David E
DE
Hinton
D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000633:toxicity; D019343:Citric Acid / Q000737:chemistry / Q000633:toxicity; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000473:pathology; D005079:Excipients / Q000737:chemistry / Q000633:toxicity*; D005880:Gills / Q000187:drug effects; D006170:Gum Arabic / Q000737:chemistry / Q000633:toxicity; D007814:Larva; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D009990:Oryzias / Q000196:embryology* / Q000254:growth & development; D011205:Povidone / Q000737:chemistry / Q000633:toxicity; D012834:Silver / Q000737:chemistry / Q000633:toxicity*; D012835:Silver Nitrate / Q000737:chemistry / Q000633:toxicity; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D000890:Anti-Infective Agents; D005079:Excipients; D014874:Water Pollutants, Chemical; D019343:Citric Acid; D012834:Silver; D006170:Gum Arabic; D012835:Silver Nitrate; D011205:Povidone