title: Engineering safer-by-design, transparent, silica-coated ZnO nanorods with reduced DNA damage potential.
abstract: Zinc oxide (ZnO) nanoparticles absorb UV light efficiently while remaining transparent in the visible light spectrum rendering them attractive in cosmetics and polymer films. Their broad use, however, raises concerns regarding potential environmental health risks and it has been shown that ZnO nanoparticles can induce significant DNA damage and cytotoxicity. Even though research on ZnO nanoparticle synthesis has made great progress, efforts on developing safer ZnO nanoparticles that maintain their inherent optoelectronic properties while exhibiting minimal toxicity are limited. Here, a safer-by-design concept was pursued by hermetically encapsulating ZnO nanorods in a biologically inert, nanothin amorphous SiO2coating during their gas-phase synthesis. It is demonstrated that the SiO2nanothin layer hermetically encapsulates the core ZnO nanorods without altering their optoelectronic properties. Furthermore, the effect of SiO2on the toxicological profile of the core ZnO nanorods was assessed using the Nano-Cometchip assay by monitoring DNA damage at a cellular level using human lymphoblastoid cells (TK6). Results indicate significantly lower DNA damage (>3 times) for the SiO2-coated ZnO nanorods compared to uncoated ones. Such an industry-relevant, scalable, safer-by-design formulation of nanostructured materials can liberate their employment in nano-enabled products and minimize risks to the environment and human health.
authors: Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA.
authors: Georgios A
authors: GA
authors: Sotiriou
authors: Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA.
authors: Christa
authors: C
authors: Watson
authors: Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA ; School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, USA.
authors: Kimberly M
authors: KM
authors: Murdaugh
authors: School of Earth Sciences, 231 Mendenhall Laboratory, The Ohio State University, Columbus, OH 43210, USA.
authors: Thomas H
authors: TH
authors: Darrah
authors: Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA.
authors: Georgios
authors: G
authors: Pyrgiotakis
authors: University of Rochester, Department of Environmental Medicine, 601 Elmwood Avenue, Rochester, NY 14642, USA.
authors: Alison
authors: A
authors: Elder
authors: Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA.
authors: Joseph D
authors: JD
authors: Brain
authors: Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA.
authors: Philip
authors: P
authors: Demokritou