Peking Univ, Dept Biol Chem, Coll Chem & Mol Engn, Beijing 100871, Peoples R China
; Peking Univ, Inst Inorgan Chem, Coll Chem & Mol Engn, Beijing 100871, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
Carbon nanotubes are promising for use in biomedical and pharmaceutical sciences. Therefore, it becomes imperative to know the basic biological properties of carbon nanotubes in vivo. We labeled the water-soluble hydroxylated carbon single-wall nanotubes with radioactive I-125 atoms, and then the tracer was used to study the distribution of hydroxylated carbon single-wall nanotubes in mice. They moved easily among the compartments and tissues of the body, behaving as small active molecules though their apparent mean molecular weight is tremendously large. This study, for the first time, affords a quantitative analysis of carbon nanotubes accumulated in animal tissues.