title: Carbon Nanotubes Released from an Epoxy-Based Nanocomposite: Quantification and Particle Toxicity.
abstract: Studies combining both the quantification of free nanoparticle release and the toxicological investigations of the released particles from actual nanoproducts in a real-life exposure scenario are urgently needed, yet very rare. Here, a new measurement method was established to quantify the amount of free-standing and protruding multiwalled carbon nanotubes (MWCNTs) in the respirable fraction of particles abraded from a MWCNT-epoxy nanocomposite. The quantification approach involves the prelabeling of MWCNTs with lead ions, nanocomposite production, abrasion and collection of the inhalable particle fraction, and quantification of free-standing and protruding MWCNTs by measuring the concentration of released lead ions. In vitro toxicity studies for genotoxicity, reactive oxygen species formation, and cell viability were performed using A549 human alveolar epithelial cells and THP-1 monocyte-derived macrophages. The quantification experiment revealed that in the respirable fraction of the abraded particles, approximately 4000 ppm of the MWCNTs were released as exposed MWCNTs (which could contact lung cells upon inhalation) and approximately 40 ppm as free-standing MWCNTs in the worst-case scenario. The release of exposed MWCNTs was lower for nanocomposites containing agglomerated MWCNTs. The toxicity tests revealed that the abraded particles did not induce any acute cytotoxic effects.
authors.affiliation: Institute of Environmental Engineering, ETH Zurich , Zurich, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Schlagenhauf
authors.affiliation: Laboratory for Particles-Biology Interactions, Empa - Swiss Federal Laboratories for Materials Science and Technology , St. Gallen, CH-9014 Switzerland.
authors.forename: Tina
authors.initials: T
authors.lastname: Buerki-Thurnherr
authors.affiliation: Institute of Environmental Engineering, ETH Zurich , Zurich, Switzerland.
authors.forename: Yu-Ying
authors.initials: YY
authors.lastname: Kuo
authors.forename: Adrian
authors.initials: A
authors.lastname: Wichser
authors.forename: Frank
authors.initials: F
authors.lastname: Nüesch
authors.affiliation: Laboratory for Particles-Biology Interactions, Empa - Swiss Federal Laboratories for Materials Science and Technology , St. Gallen, CH-9014 Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Wick
authors.affiliation: Institute of Environmental Engineering, ETH Zurich , Zurich, Switzerland.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
mesh_terms: D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D004853:Epoxy Resins / Q000737:chemistry*; D006801:Humans; D007477:Ions; D008168:Lung / Q000166:cytology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000633:toxicity*; D052638:Particulate Matter / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D018675:Toxicity Tests
chemical_list: D004853:Epoxy Resins; D007477:Ions; D037742:Nanotubes, Carbon; D052638:Particulate Matter; D017382:Reactive Oxygen Species