Internalization of CNTs into Mammalian Cells

The translocation properties of CNTs through cellular membranes may be a key factor in determining the biodistribution and cytotoxicity of CNTs. 

Another important question is whether exocytosis occurs after CNT internalization. Evidence of exocytosis of DNA-coated SWNTs in fibroblast (NIH-3T3) cells was recently presented [148]. The exocytosis rate was close to that of endocytosis after a minor temporary offset, thus keeping the accumulation of SWNTs inside the cell below the cytotoxic levels. 

Finally, the subcellular localization of CNTs is still controversial. Some reports showed that CNTs enter the cell without reaching the nucleus [140], whereas others demonstrated that CNTs can enter the nucleus [105, 141, 150]. Recently, Zhou et al. [151] demonstrated the possibility of manipulating the intracellular localization of noncovalently modified SWNTs by varying the conjugated molecule. 

---