Long‐term retention of pristine multi‐walled carbon nanotubes in rat lungs after intratracheal instillation
Autor: | Tetsuya Nakazato, Yasuo Morimoto, Takako Oyabu, Toshihiko Myojo, Norihiro Kobayashi, Masato Naya, Kazuhiro Yamamoto, Makoto Ema, Junko Nakanishi, Naohide Shinohara, Moritaka Tamura, Hiroaki Tao, Manabu Shimada, Kumiko Ohkawa |
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Rok vydání: | 2015 |
Předmět: |
Male
0301 basic medicine Acid digestion medicine.medical_specialty Intratracheal instillation Carbon nanotube Toxicology law.invention 03 medical and health sciences Microscopy Electron Transmission Limit of Detection law toxicokinetics Administration Inhalation Macrophages Alveolar medicine Animals Toxicokinetics Rats Wistar Lung Research Articles Dose-Response Relationship Drug Nanotubes Carbon Chemistry 030111 toxicology Long term retention intratracheal instillation Brain pulmonary clearance Rats Surgery multi‐walled carbon nanotube medicine.anatomical_structure Liver Toxicity nanomaterial Research Article Nuclear chemistry Clearance |
Zdroj: | Journal of Applied Toxicology |
ISSN: | 1099-1263 0260-437X |
Popis: | As a result of the growing potential industrial and medical applications of multi‐walled carbon nanotubes (MWCNTs), people working in or residing near facilities that manufacture them may be exposed to airborne MWCNTs in the future. Because of concerns regarding their toxicity, quantitative data on the long‐term clearance of pristine MWCNTs from the lungs are required. We administered pristine MWCNTs well dispersed in 0.5 mg ml−1 Triton‐X solution to rats at doses of 0.20 or 0.55 mg via intratracheal instillation and investigated clearance over a 12‐month observation period. The pristine MWCNTs pulmonary burden was determined 1, 3, 7, 28, 91, 175 and 364 days after instillation using a method involving combustive oxidation and infrared analysis, combined with acid digestion and heat pretreatment. As 0.15‐ and 0.38‐mg MWCNTs were detected 1 day after administration of 0.20 and 0.55 mg MWCNTs, respectively, approximately 30% of administrated MWCNTs may have been cleared by bronchial ciliary motion within 24 h of administration. After that, the pulmonary MWCNT burden did not decrease significantly over time for up to 364 days after instillation, suggesting that MWCNTs were not readily cleared from the lung. Transmission electron microscopy (TEM) showed that alveolar macrophages internalized the MWCNTs and retained in the lung for at least 364 days after instillation. MWCNTs were not detected in the liver or brain within the 364‐day study period ( Well‐dispersed pristine MWCNTs were administered to rats at doses of 0.20 or 0.55 mg via intratracheal instillation, and investigated clearance over a 12‐month observation period. Approximately 30% of administrated MWCNTs may have been cleared by bronchial ciliary motion within 24 h of administration. After that, the pulmonary MWCNT burden did not decrease significantly over time for up to 364 days after instillation, suggesting that MWCNTs were not readily cleared from the lung. MWCNTs were not detected in the liver or brain within the 364‐day study period. |
Databáze: | OpenAIRE |
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