Synthesis and Characterization of a Water-soluble Multi-walled Carbon Nanotube and Its Biodistribution in Mice

Abstract

In this study, we have succeeded in synthesizing and characterizing a water-soluble multi-walled carbon nanotube. Carbon nanotubes have been functionalized with many hydrophilic carboxylic groups on the surface (3-10 wt%) by a poly-carboxylation reaction and the obtained products show stable aqueous dispersion. To examine the nanotube's preliminary biocompatibility, we injected the functionalized carbon nanotube solution into mice through the tail vein. The time-profile of the subjects' body weight had a similar tendency to that of mice in a control group during 4-week post-injection examination. The injected carbon nanotube derivatives were observed in specimens of the lung and liver using a transmission electron microscope. These results suggest that the injected carbon nanotubes reach some organs through blood circulation after injection but they did not cause serious acute toxicity in mice.