Difference in carcinogenicities of two different vapor grown carbon fibers with different physicochemical characteristics induced by intratracheal instillation in rats

Particle and Fibre Toxicology

Research

Ryoji Ogawa¹  Tadashi Yoneda¹  Yuji Hagiwara¹  Ayako Nishioka¹  Hiroko Fukui¹  Kei Sato¹  Mayumi Kawabe²  Taiki Sugiyama²  Yukinori Mera²  Takamasa Numano² 

[1] Chemical Management Department, Resonac Corporation, Tokyo Shiodome Bldg.,1-9-1, Higashi-Shimbashi, 105-7325, Minato-ku, Tokyo, Japan;DIMS Institute of Medical Science, Inc., 64 Goura, Nishiazai, Azai-cho, 491-0113, Ichinomiya-shi, Aichi, Japan;

关键词: Vapor grown carbon fiber;    Multi-walled carbon nanotube;    Intratracheal instillation;    2-Year carcinogenicity study;    Rat;    Carbon fiber;    Mesothelioma;   

DOI  :  10.1186/s12989-023-00547-5

 received in 2022-08-09, accepted in 2023-08-29,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundCarbon fibers are high aspect ratio structures with diameters on the submicron scale. Vapor grown carbon fibers are contained within multi-walled carbon tubes, with VGCF™-H commonly applied as a conductive additive in lithium-ion batteries. However, several multi-walled carbon fibers, including MWNT-7, have been reported to induce lung carcinogenicity in rats. This study investigated the carcinogenic potential of VGCF™-H fibers in F344 rats of both sexes with the vapor grown carbon fibers VGCF™-H and MWNT-7 over 2 years. The carbon fibers were administered to rats by intratracheal instillation at doses of 0, 0.016, 0.08, and 0.4 mg/kg (total doses of 0, 0.128, 0.64, and 3.2 mg/kg) once per week for eight weeks and the rats were observed for up to 2 years after the first instillation.ResultsHistopathological examination showed the induction of malignant mesothelioma on the pleural cavity with dose-dependent increases observed at 0, 0.128, 0.64, and 3.2 mg/kg in rats of both sexes that were exposed to MWNT-7. On the other hand, only two cases of pleural malignant mesothelioma were observed in the VGCF™-H groups; both rats that received 3.2 mg/kg in male. The animals in the MWNT-7 groups either died or became moribund earlier than those in the VGCF™-H groups, which is thought related to the development of malignant mesothelioma. The survival rates were higher in the VGCF™-H group, and more carbon fibers were observed in the pleural lavage fluid (PLF) of the MWNT-7 groups. These results suggest that malignant mesothelioma is related to the transfer of carbon fibers into the pleural cavity.ConclusionsThe intratracheal instillation of MWNT-7 clearly led to carcinogenicity in both male and female rats at all doses. The equivocal evidence for carcinogenic potential that was observed in male rats exposed to VGCF™-H was not seen in the females. The differences in the carcinogenicities of the two types of carbon fibers are thought due to differences in the number of carbon fibers reaching the pleural cavity. The results indicate that the carcinogenic activity of VGCF™-H is lower than that of MWNT-7.

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

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