TitleSilver nanoparticle toxicity in the embryonic zebrafish is governed by particle dispersion and ionic environment.
Publication TypeJournal Article
Year of Publication2013
AuthorsKim, K-T, Truong, L, Wehmas, L, Tanguay, RL
Date Published2013 Mar 22
KeywordsAnimals, Embryo, Nonmammalian, Hydrodynamics, ions, Metal Nanoparticles, Particle Size, Silver, Spectrophotometry, Ultraviolet, Tissue Distribution, Toxicity Tests, Zebrafish

The mechanism of action of silver nanoparticles (AgNPs) is unclear due to the particles' strong tendency to agglomerate. Preventing agglomeration could offer precise control of the physicochemical properties that drive biological response to AgNPs. In an attempt to control agglomeration, we exposed zebrafish embryos to AgNPs of 20 or 110 nm core size, and polypyrrolidone (PVP) or citrate surface coatings in media of varying ionic strength. AgNPs remained unagglomerated in 62.5 μM CaCl2 (CaCl2) and ultrapure water (UP), but not in standard zebrafish embryo medium (EM). Zebrafish embryos developed normally in the low ionic strength environments of CaCl2 and UP. Exposure of embryos to AgNPs suspended in UP and CaCl2 resulted in higher toxicity than suspensions in EM. 20 nm AgNPs were more toxic than 110 nm AgNPs, and the PVP coating was more toxic than the citrate coating at the same particle core size. The silver tissue burden correlated well with observed toxicity but only for those exposures where the AgNPs remained unagglomerated. Our results demonstrate that size- and surface coating-dependent toxicity is a result of AgNPs remaining unagglomerated, and thus a critical-design consideration for experiments to offer meaningful evaluations of AgNP toxicity.

Alternate JournalNanotechnology
PubMed ID23449170
PubMed Central IDPMC3782284
Grant ListF31 ES019445 / ES / NIEHS NIH HHS / United States
P30 ES000210 / ES / NIEHS NIH HHS / United States
R01 ES016896 / ES / NIEHS NIH HHS / United States