Nose-to-Brain Transport of Aerosolized Quantum Dots Following Acute Exposure

• Published in: Nanotoxicology 2014-12, Vol.8 (8), p.885-893
• Main Authors: Hopkins, Laurie E., Patchin, Esther S., Chiu, Po-Lin, Brandenberger, Christina, Smiley-Jewell, Suzette, Pinkerton, Kent E.
• Format: Article
• Language: English
• ISSN: 1743-5390; 1743-5404
• DOI: 10.3109/17435390.2013.842267

Nanoparticles are of wide interest due to their potential use for diverse commercial applications. Quantum dots are semiconductor nanocrystals possessing unique optical and electrical properties. Although quantum dots are commonly made of cadmium, a metal known to have neurological effects, potential transport of quantum dots directly to the brain has not been assessed. This study evaluated whether quantum dots (CdSe/ZnS nanocrystals) could be transported from the olfactory tract to the brain via inhalation. Adult C57BL/6 mice were exposed to an aerosol of quantum dots for one hour via nasal inhalation, and nanoparticles were detected three hours post-exposure within the olfactory tract and olfactory bulb by a wide range of techniques, including visualization via fluorescent and transmission electron microscopy. We conclude that following short-term inhalation of solid quantum dot nanoparticles, there is rapid olfactory uptake and axonal transport to the brain/olfactory bulb with observed activation of microglial cells, indicating a pro-inflammatory response. To our knowledge, this is the first study to clearly demonstrate that quantum dots can be rapidly transported from the nose to the brain by olfactory uptake via axonal transport following inhalation.