Researchers have found that the administration of multi-walled carbon nanotubes (MWCNTs) could result in the development of mesothelioma just like asbestos.
This research has been published online in the journal of Cancer Science.
Recently in a similar research, we reported that scientists, after working on the mouse models, have published in the journal of Toxicological Sciences that, nanofibers, which could be 1000 times smaller than a human hair, could result in the development of mesothelioma. Researchers found that larger nanofibers are more dangerous.
Now in this research again scientists, after working on rats, found that when the MWCNTs were administered into the peritoneal cavity – a space between the two membranes separating the organs in the abdominal cavity from the abdominal wall – could result in the development of mesothelioma due to the fibrous structures of MWCNTs, which is similar to the asbestos. Researchers administered carbon nanotubes into the lungs through the trachea and found potential induction of mesothelial proliferation.
You can read the abstract of the paper here,
Multi-walled carbon nanotubes have a fibrous structure similar to asbestos and induce mesothelioma when injected into the peritoneal cavity. In this study, we investigated whether carbon nanotubes administered into the lung through the trachea induce mesothelial lesions. Male F344 rats were treated with 0.5 ml of 500 μg/ml suspensions of multi-walled carbon nanotubes or crocidolite 5 times over a 9 day-period by intra-pulmonary spraying. Pleural cavity lavage fluid, lung and chest wall were then collected. Multi-walled carbon nanotubes and crocidolite were found mainly in alveolar macrophages and mediastinal lymphnodes. Importantly, the fibers were also found in the cell pellets of the pleural cavity lavage, mostly in macrophages. Both multi-walled carbon nanotubes and crocidolite treatment induced hyperplastic proliferative lesions of the visceral mesothelium, their PCNA indices being about 10-fold that of the vehicle control. The hyperplastic lesions were associated with inflammatory cell infiltration and inflammation-induced fibrotic lesions of the pleural tissues. The fibers were not found in the mesothelial proliferative lesions themselves. In the pleural cavity, abundant inflammatory cell infiltration, mainly composed of macrophages, was observed. Conditioned cell culture media of macrophages treated with multi-walled carbon nanotubes and crocidolite and the supernatants of pleural cavity lavage fluid from the dosed rats increased mesothelial cell proliferation in vitro, suggesting that mesothelial proliferative lesions were induced by inflammatory events in the lung and pleural cavity and likely mediated by macrophages. In conclusion, intra-pulmonary administration of MWCNTs, like asbestos, induced mesothelial proliferation potentially associated with mesothelioma development.
Jiegou Xu, Mitsuru Futakuchi, Hideo Shimizu, David B. Alexander, Kazuyoshi Yanagihara, Katsumi Fukamachi, Masumi Suzui, Jun Kanno, Akihiko Hirose, Akio Ogata, Yoshimitsu Sakamoto, Dai Nakae, Toyonori Omori, Hiroyuki Tsuda, (2012). Multi-walled carbon nanotubes translocate into the pleural cavity and induce visceral mesothelial proliferation in rats. Cancer Science, DOI: 10.1111/cas.12005