title: Ecotoxicity of bare and coated silver nanoparticles in the aquatic midge, Chironomus riparius.
abstract: Although sediment is generally considered to be the major sink for nanomaterials in aquatic environments, few studies have addressed the ecotoxicity of nanomaterials in the presence of sediment. In the present study, the ecotoxicity of silver nanoparticles (AgNPs) with a range of organic coatings was examined in a freshwater sediment-dwelling organism, Chironomus riparius, using acute and chronic ecotoxicity endpoints, including molecular indicators. The toxicity of AgNPs coated with different organic materials, such as polyvinylpyrrolidone, gum arabic, and citrate, to C. riparius was compared with that of bare-AgNPs and AgNO3 (ionic silver). Total silver concentration was also measured to monitor the behavior of the AgNPs in water and sediment and to determine how ion dissolution affects the toxicity of all AgNPs. The coated- and bare-AgNPs caused DNA damage and oxidative stress-related gene expression. In addition, the bare-AgNPs and AgNO3 had a significant effect on development and reproduction. The surface coatings generally mitigated the toxicity of AgNPs to C. riparius, which can be explained by the reduced number of ions released from coated-AgNPs. Citrate-AgNPs caused the most significant alteration at the molecular level, but this did not translate to higher-level effects. Finally, comparing previously conducted studies on AgNP-induced gene expression without sediments, the authors show that the presence of sediment appears to mitigate the toxicity of AgNPs.
authors.affiliation: School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul, South Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Park
authors.affiliation: School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul, South Korea.
authors.forename: Jiwoong
authors.initials: J
authors.lastname: Chung
authors.affiliation: Department of Biology, Duke University, Durham, North Carolina, USA.|Center for the Environmental Implications of NanoTechnology, Duke University, Durham, North Carolina, USA.
authors.forename: Benjamin P
authors.initials: BP
authors.lastname: Colman
authors.affiliation: Center for the Environmental Implications of NanoTechnology, Duke University, Durham, North Carolina, USA.|Department of Environmental Science and Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, Texas, USA.
authors.forename: Cole W
authors.initials: CW
authors.lastname: Matson
authors.affiliation: Department of Chemical Engineering, Kwangwoon University, Seoul, South Korea.
authors.forename: Younghun
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Risk Assessment Division, National Institute of Environmental Research, Incheon, Korea.
authors.forename: Byung-Cheon
authors.initials: BC
authors.lastname: Lee
authors.affiliation: Risk Assessment Division, National Institute of Environmental Research, Incheon, Korea.
authors.forename: Phil-Je
authors.initials: PJ
authors.lastname: Kim
authors.affiliation: Risk Assessment Division, National Institute of Environmental Research, Incheon, Korea.
authors.forename: Kyunghee
authors.initials: K
authors.lastname: Choi
authors.affiliation: School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul, South Korea.
authors.forename: Jinhee
authors.initials: J
authors.lastname: Choi
mesh_terms: D000818:Animals; D002683:Chironomidae / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D019343:Citric Acid / Q000737:chemistry; D004249:DNA Damage / Q000187:drug effects*; D019015:Geologic Sediments / Q000737:chemistry; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D011205:Povidone; D012834:Silver / Q000737:chemistry*; D018675:Toxicity Tests; D059467:Transcriptome / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D019476:Insect Proteins; D014874:Water Pollutants, Chemical; D019343:Citric Acid; D012834:Silver; D011205:Povidone
keywords: Genotoxicity; Invertebrate toxicology; Nanoecotoxicology; Sediment toxicity