This works investigates embedding metal nanoparticles (NPs) in porous silica shells to reduce or entirely mitigate the metal NPs toxicity while still providing access to the metal NP surface; hence maintaining functionality of the embedded NP. The materials were structured as hollow and non-hollow core-shell Ni@SiO2 materials and as simple, surface-deposited Ni-on-SiO2. A thorough physiochemical assessment of these nanomaterials, including agglomeration, settling and dissolution, was combined with 5-day embryo zebrafish toxicity studies. Our results show that all three nanomaterials significantly reduce the toxicity of metal NPs compared to the equivalent dosing of the metal salt (NiCl2). While the engineered nanomaterials showed limited dissolution of metal ions, the Ni uptake was in fact significantly enhanced as compared to the respective Ni salt, suggesting the presence of a “trojan horse” transport mechanism into the fish. The zebrafish studies were extended to include motility analysis for sensitive toxicity analysis. The motility studies revealed dose-dependent toxicity for Ni-on-SiO2 and hollow Ni@SiO2, while non-hollow Ni@SiO2 had no toxic effect. Correlating the toxicity results with the physicochemical characteristics indicates that the toxicity of these materials does not result from externally dissolved Ni, and that nano-specific effects may be contributing to zebrafish nanotoxicity.
Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2014: Electronics, Manufacturing, Environment, Energy & Water
Published: June 15, 2014
Pages: 127 - 130
Industry sectors: Advanced Materials & Manufacturing | Energy & Sustainability
Topics: Advanced Manufacturing, Environmental Health & Safety of Nanomaterials