Research Article

Nano Research

, Volume 1, Issue 4, pp 351-360

Open Access This content is freely available online to anyone, anywhere at any time.

Effect of nucleases on the cellular internalization of fluorescent labeled DNA-functionalized single-walled carbon nanotubes

  • Hye Kyung MoonAffiliated withDepartment of Chemistry, Pohang University of Science and Technology (POSTECH)
  • , Chan Il ChangAffiliated withDepartment of Chemistry, Sungkyunkwan University, Natural Science Campus
  • , Dong-Ki LeeAffiliated withDepartment of Chemistry, Sungkyunkwan University, Natural Science Campus Email author 
  • , Hee Cheul ChoiAffiliated withDepartment of Chemistry, Pohang University of Science and Technology (POSTECH) Email author 

Abstract

Nuclease effects on the cell internalization of single-walled carbon nanotubes (SWNTs) functionalized with fluorescent-labeled DNA in serum containing cell growth media were examined. When Cy3-labeled DNA-functionalized SWNT conjugates (Cy3DNA-SWNTs) were incubated with HeLa cells in a fatal bovine serum (FBS) medium, a high fl uorescence intensity was obtained from the cells, indicative for the high level inclusion of Cy3DNA-SWNTs. However, the fluorescence intensity was remarkably reduced if Cy3DNA-SWNTs were incubated with cells in the FBS-free medium. Further systematic control experiments revealed that Cy3 dye molecules were released from Cy3DNA-SWNT conjugates by nuclease, and the free Cy3 dyes penetrate into HeLa cell with high efficiency. Although the actual amounts of SWNTs internalized in the cells were almost identical for both cells incubated in the FBS-present and FBS-absent media according to the Raman measurements, one should be cautious to determine the degree of SWNT internalization based on the fluorescence intensities especially when the coloring dye molecules were linked to oligonucleotides in nuclease containing media.

http://static-content.springer.com/image/art%3A10.1007%2Fs12274-008-8038-z/MediaObjects/12274_2008_8038_Fig1_HTML.jpg

Keywords

Single-walled carbon nanotube oligonucleotide cellular delivery molecular transporter nuclease