title: Intracellular uptake, trafficking and subcellular distribution of folate conjugated single walled carbon nanotubes within living cells.
abstract: Herein we studied the uptake, trafficking and distribution of folate conjugated single walled carbon nanotubes (SWNTs) within living cells. SWNTs were noncovalently functionalized with chitosan and then linked with folate acid and fluorescence dye Alexa Fluor 488 (denoted FA-SWNTs). Hep G2 cells were cultured in vitro and incubated with FA-SWNTs at different levels. The FA-SWNTs exhibited a concentration-dependent uptake within Hep G2 cells, and Hep G2 cells were able to internalize FA-SWNTs via a folate receptor-mediated pathway. The distribution of nanotubes inside cells demonstrated that the FA-SWNTs only locate in the cytoplasm and not in nuclei, indicating the failure of transporting through the nuclear envelope. Transmission electron microscope (TEM) results showed the presence of FA-SWNTs in lysosomes and the discharge to extracellular space after incubation with nanotubes for 5 h. No obvious cellular death rate was observed when the concentration of nanotubes was below 50 µg ml(-1). However, cells with FA-SWNT uptake showed a concentration-dependent apoptosis. These discoveries might be helpful for understanding the interaction of SWNTs and living cells.
authors.affiliation: College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Kang
authors.forename: De-Cai
authors.initials: DC
authors.lastname: Yu
authors.forename: Shu-Quan
authors.initials: SQ
authors.lastname: Chang
authors.forename: Da
authors.initials: D
authors.lastname: Chen
authors.forename: Yao-Dong
authors.initials: YD
authors.lastname: Dai
authors.forename: Yitao
authors.initials: Y
authors.lastname: Ding