title: NADPH oxidase-dependent degradation of single-walled carbon nanotubes in macrophages.
abstract: Previous studies have shown that carboxylated single-walled carbon nanotubes (SWCNTs) could be oxidatively biodegraded by neutrophil myeloperoxidase (MPO) and peroxynitrite (ONOO-). However, the biodegradation mechanism of nanotubes in macrophages has not been explored enough. Here, we showed that both MPO and ONOO-could effectively oxidize SWCNTs to generate shorter and oxidative nanotubes in vitro. SWCNTs were significantly degraded in zymosan-stimulated macrophages, and the degradation mechanism was dependent on MPO and ONOO--driven oxidative pathways of activated macrophages, where NADPH oxidase was found to be a major determinant of the biodegradation process. Moreover, the functionalization of IgG to SWCNTs could stimulate MPO release and ONOO-formation in macrophages, thereby creating the conditions favorable for degradation of nanotubes and subsequently contributing to the higher degradation degree of IgG-coated SWCNTs. Therefore, our discovery of NADPH oxidase-dependent SWCNTs degradation in activated macrophages will open new opportunities for the regulation of SWCNTs fate in vivo.
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education; Key Laboratory of Green Chemistry, Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education; Key Laboratory of Green Chemistry, Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Tian
authors.affiliation: Department of Physics, University of Houston, Houston, TX, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Physics, University of Houston, Houston, TX, USA.
authors.forename: Jianfa
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education; Key Laboratory of Green Chemistry, Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, China. naihaolu@jxnu.edu.cn.
authors.forename: Naihao
authors.initials: N
authors.lastname: Lu
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002460:Cell Line; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D019255:NADPH Oxidases / Q000737:chemistry*; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009504:Neutrophils / Q000201:enzymology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D009195:Peroxidase / Q000737:chemistry*; D030421:Peroxynitrous Acid / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D007074:Immunoglobulin G; D037742:Nanotubes, Carbon; D017382:Reactive Oxygen Species; D030421:Peroxynitrous Acid; D009195:Peroxidase; D019255:NADPH Oxidases; D010100:Oxygen