Biocompatibility analysis of halloysite clay nanotubes

The biocompatibility of four different halloysite clay nanotubes (HNT-N,-U,-P,-S), from various deposits in the world, was evaluated. More precisely, we tested their cytogenetic effects through MTT assay (for cytotoxic effects), and CBMN assay (for genotoxic effects) on mammalian cell cultures (CHO, HeLa, and HepG2 cell lines). Our results indicated a generally high level of biocompatibility of these new-generation products, however at high concentrations, and long times of exposition, we observed a moderate level of toxicity. Thus, we suggest caution in the future use of great amounts of HNTs due to their effects on living organisms.