title: Non-functionalized multi-walled carbon nanotubes alter the paracellular permeability of human airway epithelial cells.
abstract: Little information is available upon the effects of carbon nanotubes (CNT) on the airway barrier. Here we study the barrier function of Calu-3 human airway epithelial cells, grown on permeable filters, after the exposure to commercial single-walled or multi-walled CNT, produced through chemical vapour deposition. To assess changes in the paracellular permeability of CNT-treated Calu-3 monolayers, we have measured the trans-epithelial electrical resistance (TEER) and the permeability to mannitol. Multi-walled CNT caused a large decrease in TEER and an increase in mannitol permeability but no substantial alteration in monolayer viability. Single-walled CNT produced much smaller changes of TEER while CNT, synthesized through the arc discharge method, and Carbon Black nanoparticles had no effect. If commercial multi-walled CNT were added during the formation of the tight monolayer, no further increase in trans-epithelial resistance was observed. Moreover, the same nanomaterials, but neither single-walled counterparts nor Carbon Black, prevented the TEER recovery observed after the discontinuation of interleukin-4, a Th2 cytokine that causes a reversible barrier dysfunction in airway epithelia. These findings suggest that commercial multi-walled CNT interfere with the formation and the maintenance of tight junctional complexes in airway epithelial cells.
authors.affiliation: Department of Experimental Medicine, Unit of General and Clinical Pathology, University of Parma, via Volturno 14, 43100 Parma, Italy.
authors.forename: Bianca Maria
authors.initials: BM
authors.lastname: Rotoli
authors.forename: Ovidio
authors.initials: O
authors.lastname: Bussolati
authors.forename: Massimiliano G
authors.initials: MG
authors.lastname: Bianchi
authors.forename: Amelia
authors.initials: A
authors.lastname: Barilli
authors.forename: Chidambara
authors.initials: C
authors.lastname: Balasubramanian
authors.forename: Stefano
authors.initials: S
authors.lastname: Bellucci
authors.forename: Enrico
authors.initials: E
authors.lastname: Bergamaschi
mesh_terms: D045744:Cell Line, Tumor; D002463:Cell Membrane Permeability / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects*; D006801:Humans; D007202:Indicators and Reagents; D008264:Macrophages / Q000187:drug effects; D008353:Mannitol / Q000378:metabolism; D043942:Nanotubes / Q000633:toxicity*; D010078:Oxazines; D020545:Respiratory Mucosa / Q000166:cytology / Q000187:drug effects*; D014966:Xanthenes
chemical_list: D007202:Indicators and Reagents; D010078:Oxazines; D014966:Xanthenes; C005843:resazurin; D008353:Mannitol