ToxSci Advance Access originally published online on February 22, 2006
Toxicological Sciences 2006 91(1):227-236; doi:10.1093/toxsci/kfj140
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pulmonary Instillation Studies with Nanoscale TiO2 Rods and Dots in Rats: Toxicity Is not Dependent upon Particle Size and Surface Area
* DuPont Haskell Laboratory for Health and Environmental Sciences, Newark, Delaware; and Department of Chemistry, Rice University, Houston, Texas
Received November 28, 2005; accepted January 31, 2006
Pulmonary toxicology studies in rats demonstrate that nanoparticles administered to the lung are more toxic than larger, fine-sized particles of similar chemistry at identical mass concentrations. The aim of this study was to evaluate the acute lung toxicity in rats of intratracheally instilled pigment-grade TiO2 particles (rutile-type particle size = 
300 nm) versus nanoscale TiO2 rods (anatase = 200 nm x 35 nm) or nanoscale TiO2 dots (anatase = 10 nm) compared with a positive control particle type, quartz. Groups of rats were instilled with doses of 1 or 5 mg/kg of the various particle types in phosphate-buffered saline (PBS). Subsequently, the lungs of PBS- and particle-exposed rats were assessed using bronchoalveolar lavage fluid biomarkers, cell proliferation methods, and by the histopathological evaluation of lung tissue at 24 h, 1 week, 1 month, and 3 months postinstillation exposure. Exposures to nanoscale TiO2 rods or nanoscale TiO2 dots produced transient inflammatory and cell injury effects at 24 h postexposure (pe) and were not different from the pulmonary effects of larger sized TiO2 particle exposures. In contrast, pulmonary exposures to quartz particles in rats produced a dose-dependent lung inflammatory response characterized by neutrophils and foamy lipid-containing alveolar macrophage accumulation as well as evidence of early lung tissue thickening consistent with the development of pulmonary fibrosis. The results described herein provide the first example of nanoscale particle types which are not more cytotoxic or inflammogenic to the lung compared to larger sized particles of similar composition. Furthermore, these findings run counter to the postulation that surface area is a major factor associated with the pulmonary toxicity of nanoscale particle types.
Key Words: titanium dioxide particles; pulmonary toxicity; nanoscale TiO2 rods and dots; particle size; particle surface area.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J. W. Card, D. C. Zeldin, J. C. Bonner, and E. R. Nestmann Pulmonary applications and toxicity of engineered nanoparticles Am J Physiol Lung Cell Mol Physiol, September 1, 2008; 295(3): L400 - L411. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Nemmar, K. Melghit, and B. H. Ali The Acute Proinflammatory and Prothrombotic Effects of Pulmonary Exposure to Rutile TiO2 Nanorods in Rats Experimental Biology and Medicine, May 1, 2008; 233(5): 610 - 619. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. T. Stern and S. E. McNeil Nanotechnology Safety Concerns Revisited Toxicol. Sci., January 1, 2008; 101(1): 4 - 21. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. D. MAYNARD Nanotechnology: The Next Big Thing, or Much Ado about Nothing? Ann. Hyg., January 1, 2007; 51(1): 1 - 12. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. B. Warheit, T. R. Webb, V. L. Colvin, K. L. Reed, and C. M. Sayes Pulmonary Bioassay Studies with Nanoscale and Fine-Quartz Particles in Rats: Toxicity is Not Dependent upon Particle Size but on Surface Characteristics Toxicol. Sci., January 1, 2007; 95(1): 270 - 280. [Abstract] [Full Text] [PDF]
|
|