title: Media ionic strength impacts embryonic responses to engineered nanoparticle exposure.
abstract: Embryonic zebrafish were used to assess the impact of solution ion concentrations on agglomeration and resulting in vivo biological responses of gold nanoparticles (AuNPs). The minimum ion concentration necessary to support embryonic development was determined. Surprisingly, zebrafish exhibit no adverse outcomes when raised in nearly ion-free media. During a rapid throughput screening of AuNPs, 1.2-nm 3-mercaptopropionic acid-functionalized AuNPs (1.2-nm 3-MPA-AuNPs) rapidly agglomerate in exposure solutions. When embryos were exposed to 1.2-nm 3-MPA-AuNPs dispersed in low ionic media, both morbidity and mortality were induced, but when suspended in high ionic media, there was little to no biological response. We demonstrated that the media ionic strength greatly affects agglomeration rates and biological responses. Most importantly, the insensitivity of the zebrafish embryo to external ions indicates that it is possible, and necessary, to adjust the exposure media conditions to optimize NP dispersion prior to assessment.
authors.affiliation: Department of Environmental and Molecular Toxicology, The Sinnhuber Aquatic Research Laboratory and the Environmental Health Sciences Center at Oregon State University, Corvallis, OR 97333, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Truong
authors.forename: Tatiana
authors.initials: T
authors.lastname: Zaikova
authors.forename: Erik K
authors.initials: EK
authors.lastname: Richman
authors.forename: James E
authors.initials: JE
authors.lastname: Hutchison
authors.forename: Robert L
authors.initials: RL
authors.lastname: Tanguay
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002823:Chorion / Q000187:drug effects; D003470:Culture Media / Q000737:chemistry / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000473:pathology; D047108:Embryonic Development / Q000187:drug effects*; D006046:Gold / Q000737:chemistry / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D009994:Osmolar Concentration; D010316:Particle Size; D015027:Zebrafish / Q000196:embryology
chemical_list: D003470:Culture Media; D006046:Gold