title: A comparison of three dispersion media on the physicochemical and toxicological behavior of TiO2 and NiO nanoparticles.
abstract: Nanomaterials represent a burgeoning field of technological innovation. With the onset of environmental release and commercial product exposure associated with nanomaterial manufacture and proliferation, the concomitant effects on human health remain unknown and demand further investigation. Agglomeration of nanomaterials in biologically relevant media used in in vitro methods further complicates dosing in toxicological study.
  
  
  OBJECTIVE
  to compare the effects of in vitro dispersion techniques on the physicochemical and toxicological dosimetry of TiO2 (<50 nm) and NiO (<20 nm) nanoparticles and some resulting toxicological endpoints to test for potential effects.
  
  
  METHODS
  three media were prepared for A549 and 16hbe14o cells with varying concentrations of TiO2 and NiO nanoparticles. Physicochemical effects were analyzed with dynamic light scattering, ICP-MS, SEM, and TEM. Toxicological effects were determined after stimulation of cells with nanoparticles for 4 and 24h followed by analysis of inflammatory and oxidative stress markers with ELISA and RT-PCR. Our data show that dispersion media differentially affect physicochemical properties and toxicological endpoints. Therefore, we conclude that in vitro nanotoxicology models that use re-suspension methods of exposure yield inconsistent and misleading biological results due to physicochemical variation of particle characteristics and transport processes.
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Erika R
authors.initials: ER
authors.lastname: Gutierrez
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Kamens
authors.affiliation: Department of Chemistry and Biochemistry, Rowan University, Chapel Hill, NC, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Tolocka
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Sexton
authors.affiliation: Center for Environmental Medicine, Asthma, and Lung Biology, School of Medicine, University of North Carolina-Chapel Hill, Chapel Hill, NC, USA. Electronic address: ilona_jaspers@med.unc.edu.
authors.forename: Ilona
authors.initials: I
authors.lastname: Jaspers
mesh_terms: D002460:Cell Line / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D051547:Heme Oxygenase-1 / Q000235:genetics; D006801:Humans; D008027:Light; D013058:Mass Spectrometry / Q000379:methods; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D009532:Nickel / Q000737:chemistry* / Q000633:toxicity*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012542:Scattering, Radiation; D014025:Titanium / Q000737:chemistry* / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods*
chemical_list: C009495:titanium dioxide; D009532:Nickel; C028007:nickel monoxide; D014025:Titanium; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1
keywords: A549 cells; Dosimetry; Nanoparticles; NiO; TiO(2)