Preparation and binding study of a complex made of DNA-treated single-walled carbon nanotubes and antibody for specific delivery of a “molecular heater” platform

Minoru Kawaguchi,^1,2 Jun Yamazaki,^2,3 Jun Ohno,^2,4 Tadao Fukushima<sup>2,5

1</sup>Department of Dental Engineering, Biomaterials Section, Fukuoka Dental College, Sawara-ku, Fukuoka; ²Japan Science and Technology Agency, Core Research of Evolutional Science and Technology, Chiyoda-ku, Tokyo; ³Department of Physiological Science and Molecular Biology, Section of Cellular and Molecular Regulation, ⁴Department of Morphological Biology, Pathology Section, ⁵Center for Regenerative Medicine, Fukuoka Dental College, Sawara-ku, Fukuoka, Japan

Abstract: Carbon nanotubes have been explored as heat-delivery vehicles for thermal ablation of tumors. To use single-walled carbon nanotubes (SWNT) as a “molecular heater” for hyperthermia therapy in cancer, stable dispersibility and smart-delivery potential will be needed, as well as lack of toxicity. This paper reports the preparation of a model complex comprising DNA-treated SWNT and anti-human IgG antibody and the specific binding ability of this model complex with the targeted protein, ie, human IgG. Treatment with double-stranded DNA enabled stable dispersibility of a complex composed of SWNT and the antibody under physiological conditions. Quartz crystal microbalance results suggest that there was one immobilized IgG molecule to every 21,700 carbon atoms in the complex containing DNA-treated SWNT and the antibody. The DNA-SWNT antibody complex showed good selectivity for binding to the targeted protein. Binding analysis revealed that treatment with DNA did not interfere with binding affinity or capacity between the immobilized antibody and the targeted protein. The results of this study demonstrate that the DNA-SWNT antibody complex is a useful tool for use as a smart “molecular heater” platform applicable to various types of antibodies targeting a specific antigen.

Keywords: carbon nanotubes, DNA functionalization, complex, antibody, binding ability