Conclusions - Are CNTs safe

To summarize information on CNT toxicity, in Tables 7.2 and 7.3 are compiled in vitro and in vivo toxicity outcomes, respectively, after exposure to CNTs. 

At first glance, the in vitro studies on CNT toxicity appear to be confusing, inconclusive, or contradictory. However, if one considers interference with dye-based viability assays, agglomeration issues, and oxidative stress due to catalyst contamination, the data available to date seem to favor the conclusion that well-dispersed, purified, and/or functionalized CNTs exhibit relatively low toxicity. 

CNTs tested Production method and impurities content Cellular model Cytotoxic effect Ref. 

Dermal cytotoxicity SWNTs Arc discharge A549 Catalysts worsen cytotoxicity [53] 

SWNTs Arc discharge ( 1 wt% Ni and Y) HaCaT Reduced cell proliferation [26] 

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