Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.18/4671
Título: Contribution to macrophage activation to the genotoxic effect of nanofibers in lung epithelium
Autor: Ventura, C.
Uva, A.S.
Silva, M.J.
Palavras-chave: Genotoxicity
Nanofibers
Genotoxicidade Ambiental
Nanotoxicologia
Data: Jun-2016
Resumo: Nanofibers are nano-objects with two similar dimensions in the nanoscale (size range from approximately 1nm to 100nm) and the third dimension significantly larger. The most widespread group of nanofibers is carbon nanotubes (CNTs) that consist of graphite sheets with a cylindrical arrangement of various lengths, and diameter at the nanoscale. CNTs may have a single, double or multiple walls arranged in concentric layers, and embedded metals. In recent years, several studies performed in rodents exposed to liquid suspensions of CNTs by intratracheal instillation or pharyngeal aspiration showed the development of acute or persistent pulmonary inflammation and persistent interstitial fibrosis with granuloma formation, and bronchiolar or bronchioloalveolar hyperplasia. High thin and crystalline CNTs may also have a carcinogenic effect similar to asbestos. Macrophages play a key role in the response to poorly soluble nanomaterials as nanofibers. Activated macrophages degrade SWCNTs via NADPH oxidase pathway facilitating lung clearance, and if oxidative species formation is exaggerated, injury to the neighbour cells can occur. After macrophage activation, nanofibers phagocytosis also leads to the release of cytokines (TNF-α, IL-6, etc.) and transcription factors associated to inflammation (NF-κB and AP-1). In addition, when nanofiber length exceeds the pleural macrophages length, it triggers an inflammatory response in the pleural cavity due to "frustrated phagocytosis", which in turn stimulates a cytokine proinflammatory response by adjacent mesothelial cells. Thin and highly crystalline CNTs may also have a piercing effect in the mesothelial cell membrane causing in vitro cytotoxicity, and in vivo inflammatory and carcinogenic effects. The aim of this work is to elucidate the role of macrophage activation in the genotoxic effects of a thick and high aspect ratio multiwalled CNT in human lung epithelium.
Peer review: yes
URI: http://hdl.handle.net/10400.18/4671
Aparece nas colecções:DGH - Posters/abstracts em congressos internacionais



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