title: Surface coatings of ZnO nanoparticles mitigate differentially a host of transcriptional, protein and signalling responses in primary human olfactory cells.
abstract: BACKGROUND
  Inhaled nanoparticles have been reported in some instances to translocate from the nostril to the olfactory bulb in exposed rats. In close proximity to the olfactory bulb is the olfactory mucosa, within which resides a niche of multipotent cells. Cells isolated from this area may provide a relevant in vitro system to investigate potential effects of workplace exposure to inhaled zinc oxide nanoparticles.
  
  
  METHODS
  Four types of commercially-available zinc oxide (ZnO) nanoparticles, two coated and two uncoated, were examined for their effects on primary human cells cultured from the olfactory mucosa. Human olfactory neurosphere-derived (hONS) cells from healthy adult donors were analyzed for modulation of cytokine levels, activation of intracellular signalling pathways, changes in gene-expression patterns across the whole genome, and compromised cellular function over a 24 h period following exposure to the nanoparticles suspended in cell culture medium.
  
  
  RESULTS
  ZnO nanoparticle toxicity in hONS cells was mediated through a battery of mechanisms largely related to cell stress, inflammatory response and apoptosis, but not activation of mechanisms that repair damaged DNA. Surface coatings on the ZnO nanoparticles mitigated these cellular responses to varying degrees.
  
  
  CONCLUSIONS
  The results indicate that care should be taken in the workplace to minimize generation of, and exposure to, aerosols of uncoated ZnO nanoparticles, given the adverse responses reported here using multipotent cells derived from the olfactory mucosa.
authors.affiliation: CSIRO Advanced Materials TCP (Nanosafety), and CSIRO Animal, Food and Health Sciences, PO Box 52, North Ryde, NSW 1670, Australia. megan.osmond@csiro.au.
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Osmond-McLeod
authors.forename: Ronald I W
authors.initials: RI
authors.lastname: Osmond
authors.forename: Yalchin
authors.initials: Y
authors.lastname: Oytam
authors.forename: Maxine J
authors.initials: MJ
authors.lastname: McCall
authors.forename: Bryce
authors.initials: B
authors.lastname: Feltis
authors.forename: Alan
authors.initials: A
authors.lastname: Mackay-Sim
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Wood
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Cook
mesh_terms: D003470:Culture Media; D016207:Cytokines / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D009831:Olfactory Mucosa / Q000166:cytology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D015398:Signal Transduction / Q000187:drug effects*; D013499:Surface Properties; D014158:Transcription, Genetic / Q000187:drug effects*; D015034:Zinc Oxide / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D003470:Culture Media; D016207:Cytokines; D015034:Zinc Oxide