Human lung epithelial cells show biphasic oxidative burst after single-walled carbon nanotube contact

As applications for carbon nanotubes (CNT) expand and production annually increases, potential negative side effects of CNTs recently moved into focus of public interest. As they are very small in size and easily become airborne, the present manuscript shall focus on CNT behaviour and toxicity in the human lung and related tissues in vitro. Two possible explanations will be considered of negative side effects on cellular functions when cellular systems get in contact with CNT preparations: residual catalyst metals and amorphous carbon. Eliminating either one strongly influences and alters cellular functions and may give rise to safer products and nanotube handling. Hence, the reduction of reactive oxygen species-producing reactions caused by CNTs helps to minimize mutagenic and carcinogenic risks for humans.