Carbon nanotubes on Jurkat cells: effects on cell viability and plasma membrane potential

Carbon nanotubes (CNT) are one of the most novel attractive materials in nanotechnology for their potential multiple applications, including in the biomedical fields. The biocompatibility and toxicity of these novel nanomaterials are still largely unknown and a systematic study on biological interference is essential. We present a toxicological assessment of different types of CNT on the human tumor lymphocytic Jurkat cells. The carbon nanomaterials examined differ in preparation, size, contaminants and morphology: (1) CNT composed of MWCNT + SWCNT, with no metal contaminants; (2) MWCNT and (3) SWCNT, both with metal contaminants; (4) carbon black as control. The results indicate that CNT exert a dose- and time-dependent cytotoxic effect on Jurkat cells, inducing apoptotic cell death, accelerating the transition to secondary necrosis and increasing the extent of apoptosis induced by damaging agents; interestingly, CNT induce a plasma membrane hyperpolarization. These alterations are produced by all types of CNT, but contaminants and/or the size modulate the extent of such effects. Thus CNT deeply affect cell behavior, suggesting that they might play a role in inflammation, and recommending greater attention in terms of evaluation of exposure risks.