title: Comparison of cytotoxic and inflammatory responses of pristine and functionalized multi-walled carbon nanotubes in RAW 264.7 mouse macrophages.
abstract: The increased application of carbon nanotubes (CNTs) has raised the level of public concern regarding possible toxicities. Using in vitro cellular assays, we were able to assess the immunotoxicity of pristine multi-wall carbon nanotubes (MWCNTs) and their derivatives, covalently functionalized with carboxyl (COOH) or polyethylene glycol (PEG), in rodent macrophage cells. Moreover, special focus was placed on the role of surface modification and nanotubes aggregation on toxicity. Results showed that pristine MWCNTs reduce cell viability compared with functionalized MWCNTs in RAW 264.7 macrophages when incubated at concentrations of 25, 50, 100, 200, 400, and 800 μg/mL. However, in addition to causing cytotoxicity, functionalized MWCNTs induce serious inflammatory responses, as indicated by the production of inflammatory cytokines including TNF-α, IL-1β and IL-6 at various MWCNTs concentrations (25, 50, 100, and 200 μg/mL). Particle surface modification and dispersion status in biological medium were key factors in determining cytotoxicity. These findings imply that MWCNTs-induced inflammatory responses in macrophages may be associated with surface modification and aggregation of MWCNTs, which is reflected by alteration of inflammatory cytokine expression.
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.forename: Meng
authors.initials: M
authors.lastname: Tang
authors.forename: Lu
authors.initials: L
authors.lastname: Kong
authors.forename: Han
authors.initials: H
authors.lastname: Li
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Shanshan
authors.initials: S
authors.lastname: Zhang
authors.forename: Yuying
authors.initials: Y
authors.lastname: Xue
authors.forename: Yuepu
authors.initials: Y
authors.lastname: Pu
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D018836:Inflammation Mediators / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects*; D051379:Mice; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000633:toxicity; D056951:Photoelectron Spectroscopy; D060888:Real-Time Polymerase Chain Reaction; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D017931:DNA Primers; D018836:Inflammation Mediators; D037742:Nanotubes, Carbon