Pulmonary fibrotic response to aspiration of multi-walled carbon nanotubes [2011-07]

Details

• Alternative Title:
  Part Fibre Toxicol
• Personal Author:
  Mercer, Robert R ; Hubbs, Ann F ; Scabilloni, James F ; Wang, Liying ; Battelli, Lori A ; Friend, Sherri ; Castranova, Vincent ; Porter, Dale W
• Description:
  Background
  
  Multi-walled carbon nanotubes (MWCNTs) are new manufactured nanomaterials with a wide spectrum of commercial applications. To address the hypothesis that MWCNTs cause persistent pulmonary pathology, C57BL/6J mice were exposed by pharyngeal aspiration to 10, 20, 40 or 80 μg of MWCNTs (mean dimensions of 3.9 μm × 49 nm) or vehicle. Lungs were preserved at 1, 7, 28 and 56 days post- exposure to determine the potential regions and target cells for impact by MWCNT lung burden. Morphometric measurement of Sirius Red staining was used to assess the connective tissue response.
  
  Results
  
  At 56 days post-exposure, 68.7 ± 3.9, 7.5 ± 1.9 and 22.0 ± 5.1 percent (mean ± SE, N = 8) of the MWCNT lung burden were in alveolar macrophages, alveolar tissue and granulomatous lesions, respectively. The subpleural tissues contained 1.6% of the MWCNT lung burden. No MWCNTs were found in the airways at 7, 28 or 56 days after aspiration The connective tissue in the alveolar interstitium demonstrated a progressive increase in thickness over time in the 80 μg exposure group (0.12 ± 0.01, 0.12 ± 0.01, 0.16 ± 0.01 and 0.19 ± 0.01 μm for 1, 7, 28 and 56 days post-exposure (mean ± SE, N = 8)). Dose-response determined at 56 days post-exposure for the average thickness of connective tissue in alveolar septa was 0.11 ± 0.01, 0.14 ± .02, 0.14 ± 0.01, 0.16 ± 0.01 and 0.19 ± 0.01 μm (mean ± SE, N = 8) for vehicle, 10, 20, 40 and 80 μg dose groups, respectively.
  
  Conclusions
  
  The distribution of lung burden was predominately within alveolar macrophages with approximately 8% delivery to the alveolar septa, and a smaller but potentially significant burden to the subpleural tissues. Despite the relatively low fraction of the lung burden being delivered to the alveolar tissue, the average thickness of connective tissue in the alveolar septa was increased over vehicle control by 45% in the 40 μg and 73% in the 80 μg exposure groups. The results demonstrate that MWCNTs have the potential to produce a progressive, fibrotic response in the alveolar tissues of the lungs. However, the increases in connective tissue per μg dose of MWCNTs to the interstitium are significantly less than those previously found for single-walled carbon nanotubes (SWCNTs).
  
  
• Subjects:
  Administration, Inhalation Animals Dose-Response Relationship, Drug Granuloma Lung Male Mice Mice, Inbred C57BL Nanotubes, Carbon Pulmonary Fibrosis Research

  More +
• Source:
  Part Fibre Toxicol. 2011; 8:21.
• Document Type:
  Journal Article
• Volume:
  8
• NIOSHTIC Number:
  nn:20039133
• Collection(s):
  CDC Public Access National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:779e91d65e7a6498bcbd5f5308a489f940e64317d1c6dd0c7f72eaa243a7aa3a02ebf1feed5599224ae640f22c7a8cb5243036e88998f136eb57290cf963fa2f
• Download URL:
  https://stacks.cdc.gov/view/cdc/3658/cdc_3658_DS1.pdf
• File Type:
  [PDF - 3.75 MB ]