Comparative In Vivo Assessment of Alveolar Fibrosis, Histopathology, and Systemic Translocation Induced by Carbon Nanotubes and Nanofibers from US Facilities

Details

• Personal Author:
  Birch EM ; Bishop L ; Bunker K ; Casuccio G ; Dahm, Matthew M. ; Erdely A ; Evans DE ; Eye T ; Foster S ; Fraser K ; Friend S ; Hubbs, Ann F. ; Hubczak J ; Kodali VK ; Mercer RR ; Orandle MS ; Schubauer-Berigan, Mary K. ; Schwegler-Berry D ; Stefaniak, Aleksandr B. ; Wu NQ ; Yanamala N
• Description:
  Pulmonary exposure to carbon nanotubes or nanofibers (CNT/F) is known to induce inflammation, toxicity, or tumorigenesis, and is a concern in the occupational setting. CNT/F represent a large class of materials and it is unclear if all confer similar toxicity. Our aim was to simultaneously test the pulmonary effects induced by CNT/F with variable physicochemical properties obtained from U.S. facilities. Seven different multi-walled CNT and two CNF were characterized and evaluated for alveolar fibrosis, translocation, and histopathological changes in mice at 1, 7, 28, and 84 d following oropharyngeal aspiration to 4 or 40 microg of each material. Lung sections at 84 d post-exposure to 40 microg were microscopically evaluated to measure changes in histopathology. Moderate and multifocal granulomatous bronchopneumonia, bronchiolitis obliterans, bronchiolar epithelial hypertrophy, and peribronchial fibrosis were observed in most, but not all, high dose exposures. Variances in incidence and severity between the CNT/F correlate to physicochemical properties (e.g., particle agglomeration state, nominal tube diameter, etc.). Alveolar fibrosis was measured using morphometric point and intercept counting, and was generally increased in 7 of the 9 materials reaching significance in materials with nominal tube diameter greater than or equal to 50 nm. Tracheo-bronchial lymph node (TBLN) and liver sections at 84 d post-exposure were microscopically evaluated for particle translocation. A wide range of TBLN and liver accumulation patterns were observed, which reflect the ability of macrophages to phagocytose and clear particles dependent on size and agglomeration. Systemic translocation was limited to single tubes or fibers rather than agglomerates, meaning less systemic accumulation for smaller diameter, more agglomerated materials compared to larger diameter, and more fiber-like materials. In conclusion, histopathologic changes and translocation were dependent upon physicochemical properties such as particle agglomeration and size. Ongoing research and modeling techniques will elucidate relationships between physicochemical characteristics and toxicities of various CNT/F. [Description provided by NIOSH]
• Subjects:
  Blood Chemistry Environmental Exposure Fibrosis Immune System Laboratories Lung Lung Diseases Lymphatic System Macrophages Microbiology Occupational Health Particulate Matter Respiratory System Respiratory Tract Diseases Safety Toxicology

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• Keywords:
  Alveolar Cells Carbon Nanofibers Carbon Nanotubes Chemical Properties CNF CNT Dose Response Exposure Assessment Exposure Levels Histopathology Immune Reaction Inhalation In Vivo Study Laboratory Animals Laboratory Testing Liver Lung Cells Lung Disorders Lung Fibrosis Lymph Nodes Microscopic Analysis Multi-walled Carbon Nanotubes MWCNT Nanofibers Nanotoxicology Nanotubes Particle Diameter Particle Size Phagocytes Physical Properties Pulmonary Effects Pulmonary System Disorders Respiratory System Disorders

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; Ohio ; OSHA Region 3 ; OSHA Region 5 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; RHD - Respiratory Health Division ; DSHEFS - Division of Surveillance, Hazard Evaluations, and Field Studies ; DART - Division of Applied Research and Technology
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  168
• Issue:
  1
• NIOSHTIC Number:
  nn:20055011
• Citation:
  Toxicologist 2019 Mar; 168(1):289
• CAS Registry Number:
  Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 58th Annual Meeting and ToxExpo, March 10-14, 2019, Baltimore, Maryland
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7fc334efbe2625ae4f47e537b98595e4209590be7dcfc09228869aaf77195b32d57a1ae1d35b178f2ac79c477794c8d805c749f4da42952b68739d5ca1090a07
• Download URL:
  https://stacks.cdc.gov/view/cdc/217415/cdc_217415_DS1.pdf
• File Type:
  [PDF - 868.66 KB ]