Evidence for electro-chemical interactions between multi-walled carbon nanotubes and human macrophages

Silvana Fiorito (1) , Marc Monthioux (2) , R. Psaila (1) , P. Pierimarchi (1) , M. Zonfrillo (1) , E. d'Emilia (1) , S. Grimaldi (1) , A. Lisi (1) , François Béguin (3) , Robert Almairac (4) , Laure Noé (2) , A. Serafino (1)

1 Institute of Neurobiology and Molecular Medicine
2 CEMES - Centre d'élaboration de matériaux et d'études structurales
3 CRMD - Centre de Recherche sur la Matière Divisée
4 LCVN - Laboratoire des colloïdes, verres et nanomatériaux

Carbon multi-walled nanotubes (MWCNTs) may have several dangerous effects on different cell systems, but the mechanisms responsible for their cytotoxicity are not well known yet. At present, very little is known about the electrical interactions between nanomaterials and cells. We aimed to verify whether MWCNT electrical properties could affect the so called "charge-sensitive" cell parameters, interacting with cellular electrical activity. Human macrophages were challenged with two fully characterised MWCNT samples, one tested as-prepared (MWCNT), the other one purified (by annealing at 2400 °C) and better electro-conductive (a-MWCNT). Our findings show that a-MWCNTs are less cytotoxic but possess a higher inflammatory potential, as compared to MWCNTs. Moreover, only annealed and better conductive MWCNTs affect significantly the mitochondrial membrane polarity, the intracellular pH and the reorganisation of cytoskeleton actin filaments, cell functions strictly dependent on electro-chemical mechanisms. Based on our results, there is evidence for electro-chemical interactions taking place between cell membranes and electro-conductive MWCNTs. Such a specific behaviour could have wide-range applications in the biomedical field, not only concerning those cellular systems (neuronal and bone cells) sensitive to electrical stimuli, but also other cell systems.

Mots clés: Actin filament; Biomedical fields; Bone cells; Cell functions; Cell parameter; Cell system; Cellular system; Chemical interactions; Chemical mechanism; Cytoskeleton; Cytotoxic; Electrical activities; Electrical interaction; Electrical property; Electrical stimuli; Human macrophages; Intracellular pH; Mitochondrial membranes; Multi-walled nanotubes; Nano-materials; Reorganisation; Carbon nanotubes; Cytology; Electric properties; Macrophages; Multiwalled carbon nanotubes (MWCN); pH effects; Cell membranes

Domaines: Physique [physics]

Silvana Fiorito, Marc Monthioux, R. Psaila, P. Pierimarchi, M. Zonfrillo, et al.. Evidence for electro-chemical interactions between multi-walled carbon nanotubes and human macrophages. Carbon, 2009, 47 (12), pp.2789-2804. ⟨10.1016/j.carbon.2009.06.023⟩. ⟨hal-01760314⟩