Title: Repeated Iron-Soot Exposure and Nose-to-brain Transport of Inhaled Ultrafine Particles.

Authors: Hopkins, Laurie E; Laing, Emilia A; Peake, Janice L; Uyeminami, Dale; Mack, Savannah M; Li, Xueting; Smiley-Jewell, Suzette; Pinkerton, Kent E

Published In Toxicol Pathol, (2018 01)

Abstract: Particulate exposure has been implicated in the development of a number of neurological maladies such as multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, and idiopathic Parkinson's disease. Only a few studies have focused on the olfactory pathway as a portal through which combustion-generated particles may enter the brain. The primary objective of this study was to define the deposition, uptake, and transport of inhaled ultrafine iron-soot particles in the nasal cavities of mice to determine whether combustion-generated nanoparticles reach the olfactory bulb via the olfactory epithelium and nerve fascicles. Adult female C57B6 mice were exposed to iron-soot combustion particles at a concentration of 200 μg/m3, which included 40 μg/m3 of iron oxide nanoparticles. Mice were exposed for 6 hr/day, 5 days/week for 5 consecutive weeks (25 total exposure days). Our findings visually demonstrate that inhaled ultrafine iron-soot reached the brain via the olfactory nerves and was associated with indicators of neural inflammation.

PubMed ID: 28914166

MeSH Terms: Animals; Brain/drug effects; Female; Ferric Compounds/toxicity*; Inhalation Exposure/adverse effects*; Mice; Mice, Inbred C57BL; Mucociliary Clearance; Nanoparticles/toxicity*; Nasal Cavity/drug effects; Olfactory Bulb/drug effects; Olfactory Mucosa/drug effects; Soot/toxicity*