Using mice in an animal model study, the researchers set out to determine what happens when multi-walled carbon nanotubes are inhaled. Specifically, researchers wanted to determine whether the nanotubes would be able to reach the pleura, which is the tissue that lines the outside of the lungs and is affected by exposure to certain types of asbestos fibers which cause the cancer mesothelioma. The researchers used inhalation exposure and found that inhaled nanotubes do reach the pleura and cause health effects.
Short-term studies described in the paper do not allow conclusions about long-term responses such as cancer. However, the inhaled nanotubes "clearly reach the target tissue for mesothelioma and cause a unique pathologic reaction on the surface of the pleura, and caused fibrosis," says Dr. James Bonner, associate professor of environmental and molecular toxicology at NC State and senior author of the study. The "unique reaction" began within one day of inhalation of the nanotubes, when clusters of immune cells (lymphocytes and monocytes) began collecting on the surface of the pleura. Localized fibrosis, or scarring on parts of the pleural surface that is also found with asbestos exposure, began two weeks after inhalation.
The study showed the immune response and fibrosis disappeared within three months of exposure. However, this study used only a single exposure to the nanotubes. "It remains unclear whether the pleura could recover from chronic, or repeated, exposures," Bonner says. "More work needs to be done in that area and it is completely unknown at this point whether inhaled carbon nanotubes will prove to be carcinogenic in the lungs or in the pleural lining."
The mice received a single inhalation exposure of six hours as part of the study, and the effects on the pleura were only evident at the highest dose used by the researchers -- 30 milligrams per cubic meter (mg/m3). The researchers found no health effects in the mice exposed to the lower dose of one mg/m3.
The study, "Inhaled Carbon Nanotubes Reach the Sub-Pleural Tissue in Mice," was co-authored by Bonner, Dr. Jessica Ryman-Rasmussen, Dr. Arnold Brody, and Dr. Jeanette Shipley-Phillips of NC State, Dr. Jeffrey Everitt who is an adjunct faculty at NC State, Dr. Mark Cesta of the National Institute of Environmental Health Sciences (NIEHS), Earl Tewksbury, Dr. Owen Moss, Dr. Brian Wong, Dr. Darol Dodd and Dr. Melvin Andersen of The Hamner Institutes for Health Sciences. The study is published in the Oct. 25 issue of Nature Nanotechnology and was funded by The Hamner Institutes for Health Sciences, NIEHS and NC State's College of Agriculture and Life Sciences.
Email or share this story:|MoreStory Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by North Carolina State University, via EurekAlert!, a service of AAAS.Journal Reference:
Jessica P. Ryman-Rasmussen, Mark F. Cesta, Arnold R. Brody, Jeanette K. Shipley-Phillips, Jeffrey I. Everitt, Earl W. Tewksbury, Owen R. Moss, Brian A. Wong, Darol E. Dodd, Melvin E. Andersen & James C. Bonner. Inhaled carbon nanotubes reach the subpleural tissue in mice. Nature Nanotechnology, 2009; DOI: 10.1038/nnano.2009.305Need to cite this story in your essay, paper, or report? Use one of the following formats: APAMLA
Note: If no author is given, the source is cited instead.
Related Stories
Breakthrough In Production Of Double-Walled Carbon Nanotubes (Dec. 29, 2008) — In recent years, the possible applications for double-walled carbon nanotubes have excited scientists and engineers, particularly those working on developing renewable energy technologies. These tiny ... > read more
Carbon Nanotubes That Look Like Asbestos, Behave Like Asbestos, Could Lead To Asbestos-Related Disease (May 22, 2008) — A major study in Nature Nanotechnology suggests some forms of carbon nanotubes -- a poster child for the "nanotechnology revolution" -- could be as harmful as asbestos if inhaled in sufficient ... > read moreTweezers Trap Nanotubes By Color (Sep. 29, 2008) — Singled-walled carbon nanotubes are graphene sheets wrapped into tubes, and are typically made up of various sizes and with different amounts of twist (also known as chiralities). Each type of ... > read moreNanotubes Trigger Biochemical 'Cross Talk' For Consumer Protection Tests (Feb. 5, 2009) — Researchers in West Virginia and Japan are reporting an advance toward a blood test that could help protect consumers from new products containing potentially harmful kinds of nanotubes. These ultra ... > read moreStructural Defects Introduced Into Carbon Nanotubes Could Lead The Way To Carbon Nanotube Circuits (Jan. 15, 2009) — Structural defects introduced into carbon nanotubes could lead the way to carbon nanotube circuits, new research ... > read moreSearch ScienceDailyNumber of stories in archives: 86,508Find with keyword(s): Enter a keyword or phrase to search ScienceDaily's archives for related news topics, the latest news stories, reference articles, science videos, images, and books.
Just In:New Horned Dinosaur: Two-Ton Plant-EaterNew Species of Invertebrates in AntarcticCoastal Birds Carry Toxic Ocean Metals InlandNew Species Had Largest Horns of Any DinosaurClue to Origin of Milky Way Gas CloudsHow Do Bumblebees Get Predators to Buzz Off?Optical Legos: Building Nanoshell StructuresHuge Carbon 'Burp' Helped End Last Ice Age Science Video News
Breathing Easier with EmphysemaBy implanting a valve through the bronchia, surgeons can now prevent air from getting trapped in emphysema-stricken lungs. The valve deflates the. ... > full storyIndustrial Hygienists Reveal Dangers Of MoldPulmonologists Treat Breath Shortness with Harmonica ClassesPulmonologists Extend Lung-Transplant Patients' Lives with Inhaled Anti-Rejection Drugmore science videos 
Copyright © 1995-2010 ScienceDaily LLC — All rights reserved — Contact: editor@sciencedaily.com
Part of the iVillage Your Total Health Network
View the Original article
0 comments:
Post a Comment