title: Sorption of silver nanoparticles to laboratory plastic during (eco)toxicological testing.
abstract: Here, we evaluate the extent of sorption of silver nanoparticles (AgNPs) with different primary sizes (30 and 70 nm) and surface properties (branched polyethylene imine, "bPEI" and citrate coating) to laboratory plastic during (eco)toxicological testing. Under conditions of algal growth inhibition assay, up to 97% of the added AgNPs were sorbed onto the test vessels whereas under conditions of in vitro toxicological assay with mammalian cells, the maximum loss of AgNPs was 15%. We propose that the high concentration of proteins and biomolecules in the in vitro toxicological assay originating from serum-containing cell culture medium prevented NP sorption due to steric stabilisation. The sorption of AgNPs to test vessels was clearly concentration dependent. In the conditions of algal growth inhibition assay at 10 ng AgNPs/mL, up to 97% of AgNPs were lost from the test while at higher concentrations (1000 ng AgNPs/mL), the loss of AgNPs was remarkably smaller, up to 64%. Sorption of positively charged bPEI-coated AgNPs was more extensive than the sorption of negatively charged citrate-coated AgNPs and, when calculated on a mass basis, more 70 nm-sized Ag than 30 nm Ag sorbed to plastic surfaces. In summary, this study demonstrates that the loss of AgNPs during (eco)toxicological tests due to sorption on test vessel surfaces is significant, especially in diluted media (e.g. in algal growth medium) and at low NP concentrations. Thus, to ensure the accurate interpretation of (eco)toxicological results, the loss of AgNPs due to adsorption to test vessels should not be overlooked and considered for each specific case.
authors.affiliation: a Centre for Environmental Risk Assessment and Remediation, University of South Australia , Mawson Lakes , Australia .
authors.forename: Anzhela
authors.initials: A
authors.lastname: Malysheva
authors.affiliation: b Mawson Institute, University of South Australia , Mawson Lakes , Australia , and.
authors.forename: Angela
authors.initials: A
authors.lastname: Ivask
authors.affiliation: b Mawson Institute, University of South Australia , Mawson Lakes , Australia , and.
authors.forename: Claudia
authors.initials: C
authors.lastname: Hager
authors.affiliation: a Centre for Environmental Risk Assessment and Remediation, University of South Australia , Mawson Lakes , Australia .
authors.forename: Gianluca
authors.initials: G
authors.lastname: Brunetti
authors.affiliation: a Centre for Environmental Risk Assessment and Remediation, University of South Australia , Mawson Lakes , Australia .|c Division of Soil and Water Sciences, Faculty of Environmental Agricultural Sciences , Suez Canal University , North Sinai , Egypt.
authors.forename: Ezzat R
authors.initials: ER
authors.lastname: Marzouk
authors.affiliation: a Centre for Environmental Risk Assessment and Remediation, University of South Australia , Mawson Lakes , Australia .
authors.forename: Enzo
authors.initials: E
authors.lastname: Lombi
authors.affiliation: b Mawson Institute, University of South Australia , Mawson Lakes , Australia , and.
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Voelcker
mesh_terms: D065966:Absorption, Physicochemical; D016477:Artifacts; D001681:Biological Assay / Q000379:methods*; D019343:Citric Acid / Q000737:chemistry; D054750:Ecotoxicology / Q000379:methods*; D007097:Imines / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D010316:Particle Size; D010969:Plastics / Q000737:chemistry*; D011095:Polyethylenes / Q000737:chemistry; D012834:Silver / Q000737:chemistry* / Q000633:toxicity; D013499:Surface Properties; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D007097:Imines; D010969:Plastics; D011095:Polyethylenes; C505405:poly(ethylene imine); D019343:Citric Acid; D012834:Silver
keywords: Ag nanoparticles; algal growth medium; cell culture medium; sorption; toxicological assays