1 Il contributo alla scienza ed all’etica di Sabino Palmieri Settimio Grimaldi & Antonella Lisi CNR Roma

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12 Electro-chemically mediated effects of MWNTs on human cells S. Fiorito, A.Lisi, M. Ledda, R. Psaila, F. Andreola, M. Zonfrillo, P. Pierimarchi, S. Grimaldi and A. Serafino a Dept. of Experimental Medicine, University La Sapienza- CNR, Via Fosso del Cavaliere 100, Rome b Inst. of Neurobiology and Molecular Medicine-CNR, Via Fosso del Cavaliere 100, Rome

13 Live/Dead test and Phagocytosis Live/Dead test and Phagocytosis pMWNTs were shown to be less toxic than npMWNTs Legenda: pMWNTs= purified Multi walled nanoTube npMWNTs = non purfied….

14 Actin Cytoskeleton network were able to activate (reorganization of the actin cytoskeletal network, and stimulate the phagocytic activity of MDMs to a higher extent as compared to npMWNTs Legenda: pMWNTs= purified Multi walled nanoTube npMWNTs = non purfied….

15 Cytokines production by human macrophages pMWNTs posses a higher inflammatory potential than not purified MWNTs and graphite particles, as revealed by the higher pro- inflammatory cytokines (TNF-α, IL-6, Il-8)release by MDMs, respect to npMWNTs MWNTs 11 npMWNTs MWNTs 12 pMWNTs LPS= lipolisaccaride FURDIN = tipo di MWNT

16 Intracellular pH

17 Mitochondrial membrane depolarization

18 Control pMWNTs npMWNTs Intracellular Ca2+ Levels and Cell Membrane Depolarization

19 Pico-ammeter Measurements

20 CONCLUSIONS Purified MWNTs have been shown to be less cytotoxic and to possess a higher inflammatory potential as compared to not purified MWNTs. Moreover, they induce significant changes in the so called “charge-sensitive” cell parameters, pH, cell membrane and mitochondrial membrane potential, in a very short time. The presence of low intensity currents has been demonstrated when pMWNTs were dispersed in double distilled water. Our findings suggest that these effects could be triggered by electro-chemical rather than chemical (receptor-mediated) interactions of these CNTs with cells. These findings suggest that early electrochemical interactions, occurring between cell membranes and electro conductive multi-walled carbon nanotubes, may change in a very short time the intracellular pH and the mitochondrial membrane potential and trigger chemical signalling patways leading to macrophage activation and inflammatory molecules secretion.