title: Interaction of silver nanoparticles with algae and fish cells: a side by side comparison.
abstract: BACKGROUND
  Silver nanoparticles (AgNP) are widely applied and can, upon use, be released into the aquatic environment. This raises concerns about potential impacts of AgNP on aquatic organisms. We here present a side by side comparison of the interaction of AgNP with two contrasting cell types: algal cells, using the algae Euglena gracilis as model, and fish cells, a cell line originating from rainbow trout (Oncorhynchus mykiss) gill (RTgill-W1). The comparison is based on the AgNP behavior in exposure media, toxicity, uptake and interaction with proteins.
  
  
  RESULTS
  (1) The composition of exposure media affected AgNP behavior and toxicity to algae and fish cells. (2) The toxicity of AgNP to algae was mediated by dissolved silver while nanoparticle specific effects in addition to dissolved silver contributed to the toxicity of AgNP to fish cells. (3) AgNP did not enter into algal cells; they only adsorbed onto the cell surface. In contrast, AgNP were taken up by fish cells via endocytic pathways. (4) AgNP can bind to both extracellular and intracellular proteins and inhibit enzyme activity.
  
  
  CONCLUSIONS
  Our results showed that fish cells take up AgNP in contrast to algal cells, where AgNP sorbed onto the cell surface, which indicates that the cell wall of algae is a barrier to particle uptake. This particle behaviour results in different responses to AgNP exposure in algae and fish cells. Yet, proteins from both cell types can be affected by AgNP exposure: for algae, extracellular proteins secreted from cells for, e.g., nutrient acquisition. For fish cells, intracellular and/or membrane-bound proteins, such as the Na+/K+-ATPase, are susceptible to AgNP binding and functional impairment.
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.|School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland.|Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences (NMBU), Oslo, 0454, Norway.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yue
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.|School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.|Department of Environmental Systems Science (D-USYS), ETH-Zürich, 8092, Zürich, Switzerland.|, Wattstrasse 13a, 8307, Effretikon, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Sigg
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.|Department of Environmental Systems Science (D-USYS), ETH-Zürich, 8092, Zürich, Switzerland.
authors.forename: Marc J-F
authors.initials: MJ
authors.lastname: Suter
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.|Department of Environmental Systems Science (D-USYS), ETH-Zürich, 8092, Zürich, Switzerland.
authors.forename: Smitha
authors.initials: S
authors.lastname: Pillai
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland. renata.behra@eawag.ch.|Department of Environmental Systems Science (D-USYS), ETH-Zürich, 8092, Zürich, Switzerland. renata.behra@eawag.ch.
authors.forename: Renata
authors.initials: R
authors.lastname: Behra
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland. kristin.schirmer@eawag.ch.|School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland. kristin.schirmer@eawag.ch.|Department of Environmental Systems Science (D-USYS), ETH-Zürich, 8092, Zürich, Switzerland. kristin.schirmer@eawag.ch.
authors.forename: Kristin
authors.initials: K
authors.lastname: Schirmer
mesh_terms: D000327:Adsorption; D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors; D000818:Animals; D018929:Cell Culture Techniques; D002460:Cell Line; D003470:Culture Media / Q000737:chemistry; D004705:Endocytosis; D005056:Euglena gracilis / Q000187:drug effects*; D029941:Fish Proteins / Q000037:antagonists & inhibitors; D005880:Gills / Q000166:cytology / Q000187:drug effects*; D053768:Metal Nanoparticles / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D017686:Oncorhynchus mykiss; D010316:Particle Size; D012834:Silver / Q000493:pharmacokinetics / Q000633:toxicity*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D003470:Culture Media; D029941:Fish Proteins; D014874:Water Pollutants, Chemical; D012834:Silver; D000469:Alkaline Phosphatase; D000254:Sodium-Potassium-Exchanging ATPase
keywords: AgNP; Euglena gracilis; Nanoparticle toxicity; Nanoparticle uptake; Nanoparticle-protein interactions; RTgill-W1 cell line