Toxicity Evaluation Following Intratracheal Instillation of Iron Oxide in a Silica Matrix in Rats

Biomed Res Int. 2014;2014:134260. doi: 10.1155/2014/134260. Epub 2014 May 14.


Iron oxide-silica nanoparticles (IOSi-NPs) were prepared from a mixture of ferrous chloride tetrahydrate and ferric chloride hexahydrate dropped into a silica xerogel composite. The structure and morphology of the synthesized maghemite nanoparticles into the silica xerogel were analysed by X-ray diffraction measurements, scanning electron microscopy equipped with an energy dispersive X-ray spectrometer, and transmission electron microscopy. The results of the EDAX analysis indicated that the embedded particles were iron oxide nanoparticles. The particle size of IOSi-NPs calculated from the XRD analysis was estimated at around 12.5 nm. The average size deduced from the particle size distribution is 13.7 ± 0.6 nm, which is in good agreement with XRD analysis. The biocompatibility of IOSi-NPs was assessed by cell viability and cytoskeleton analysis. Histopathology analysis was performed after 24 hours and 7 days, respectively, from the intratracheal instillation of a solution containing 0.5, 2.5, or 5 mg/kg IOSi-NPs. The pathological micrographs of lungs derived from rats collected after the intratracheal instillation with a solution containing 0.5 mg/kg and 2.5 mg/kg IOSi-NPs show that the lung has preserved the architecture of the control specimen with no significant differences. However, even at concentrations of 5 mg/kg, the effect of IOSi-NPS on the lungs was markedly reduced at 7 days posttreatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Survival / drug effects
  • Cytoskeleton / metabolism*
  • Cytoskeleton / pathology
  • Ferric Compounds / chemistry
  • Ferric Compounds / toxicity*
  • Hep G2 Cells
  • Humans
  • Lung / metabolism*
  • Lung / pathology
  • Male
  • Nanoparticles / chemistry*
  • Nanoparticles / ultrastructure
  • Particle Size
  • Rats
  • Silicon Dioxide / chemistry
  • Silicon Dioxide / toxicity*
  • Time Factors
  • Trachea


  • Ferric Compounds
  • ferric oxide
  • Silicon Dioxide