TY - DATA T1 - Carbon Nanotube Degradation in Macrophages: Live Nanoscale Monitoring and Understanding of Biological Pathway PY - 2015/10/27 AU - Dan Elgrabli AU - Walid Dachraoui AU - Cécilia Ménard-Moyon AU - Xiao Jie Liu AU - Dominique Bégin AU - Sylvie Bégin-Colin AU - Alberto Bianco AU - Florence Gazeau AU - Damien Alloyeau UR - https://acs.figshare.com/articles/journal_contribution/Carbon_Nanotube_Degradation_in_Macrophages_Live_Nanoscale_Monitoring_and_Understanding_of_Biological_Pathway/2117839 DO - 10.1021/acsnano.5b03708.s001 L4 - https://ndownloader.figshare.com/files/3751579 KW - hydroxyl radicals KW - nanoscale investigations KW - MWCNT structure KW - ROS KW - unraveling oxidative transformations KW - carbon nanotubes KW - reactive oxygen species KW - NOX 2 KW - multiwalled carbon nanotubes KW - MWCNT degradation KW - intracellular way KW - carbon Nanotube Degradation KW - oxidative stress KW - Biological PathwayDespite KW - degradation mechanisms KW - oxidative enzymes KW - Live Nanoscale Monitoring KW - 7 days KW - nanotube degradation KW - macrophage KW - superoxide production KW - life science approaches N2 - Despite numerous applications, the cellular-clearance mechanism of multiwalled carbon nanotubes (MWCNTs) has not been clearly established yet. Previous in vitro studies showed the ability of oxidative enzymes to induce nanotube degradation. Interestingly, these enzymes have the common capacity to produce reactive oxygen species (ROS). Here, we combined material and life science approaches for revealing an intracellular way taken by macrophages to degrade carbon nanotubes. We report the in situ monitoring of ROS-mediated MWCNT degradation by liquid-cell transmission electron microscopy. Two degradation mechanisms induced by hydroxyl radicals were extracted from these unseen dynamic nanoscale investigations: a non-site-specific thinning process of the walls and a site-specific transversal drilling process on pre-existing defects of nanotubes. Remarkably, similar ROS-induced structural injuries were observed on MWCNTs after aging into macrophages from 1 to 7 days. Beside unraveling oxidative transformations of MWCNT structure, we elucidated an important, albeit not exclusive, biological pathway for MWCNT degradation in macrophages, involving NOX2 complex activation, superoxide production, and hydroxyl radical attack, which highlights the critical role of oxidative stress in cellular processing of MWCNTs. ER -