Dispersion stability and exothermic properties of DNA-functionalized single-walled carbon nanotubes

Abstract

Minoru Kawaguchi1,2, Jun Ohno2,3, Akihito Irie4, Tadao Fukushima2,5, Jun Yamazaki2,6, Naotoshi Nakashima2,71Department of Dental Engineering, Biomaterials Section, Fukuoka Dental College, Sawara-ku, Fukuoka, Japan; 2Japan Science and Technology Agency (JST), Core Research of Evolutional Science and Technology (CREST), Chiyoda-ku, Tokyo, Japan; 3Department of Morphological Biology, Pathology Section, Fukuoka Dental College, Sawara-ku, Fukuoka, Japan; 4Department of Oral Rehabilitation, Section of Oral Implantology, Fukuoka Dental College, Sawara-ku, Fukuoka, Japan; 5Department of Dental Engineering, Bioengineering Section, Fukuoka Dental College, Sawara-ku, Fukuoka, Japan; 6Department of Physiological Science and Molecular Biology, Section of cellular and Molecular Regulation, Fukuoka Dental College, Sawara-ku, Fukuoka, Japan; 7Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka, JapanAbstract: Carbon nanotubes act as a photon antenna that serves as an effective “molecular heater” around the near-infrared (NIR) region. This exothermic generation can be used as a possible heating source for hyperthermia therapy. The current study reports the dispersible and exothermic properties with NIR irradiation for single-walled carbon nanotubes (SWNTs) treated with a strong acid (acid-treated SWNTs), and the SWNTs further functionalized with double-stranded DNA (DNA-functionalized SWNTs: DNA-SWNTs). DNA-SWNTs significantly improved the dispersibility of SWNTs when compared with the acid-treated SWNTs. The binding ratio of the acid-treated SWNT and DNA was calculated to be 3.1 (DNA/SWNTs) from the phosphorous content in the DNA-SWNT. This interaction of the SWNTs and DNA would contribute to the stable dispersion of the DNA-SWNTs in a culture medium. With NIR irradiation by a halogen lamp light source, the acid-treated SWNTs and the DNA-SWNTs showed strong heat evolution in vitro (in a culture medium) and in vivo (in the subcutaneous tissue of a mouse) condition without any invasive effect on the non-SWNT area. The results of this study suggested that the functionalization with DNA was an efficient approach to improve the dispersibility of SWNTs in body fluids, and the DNA-SWNT would be a promising source for photo-induced exothermic generation.Keywords: DNA functionalization, near-infrared irradiation