X-ray computed tomography imaging of a tumor with high sensitivity using gold nanoparticles conjugated to a cancer-specific antibody via polyethylene glycol chains on their surface

• Published in: Science and technology of advanced materials Vol. 17; no. 1; pp. 387 - 397
• Main Authors: Nakagawa, Tomohiko, Gonda, Kohsuke, Kamei, Takashi, Cong, Liman, Hamada, Yoh, Kitamura, Narufumi, Tada, Hiroshi, Ishida, Takanori, Aimiya, Takuji, Furusawa, Naoko, Nakano, Yasushi, Ohuchi, Noriaki
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01.01.2016; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: 30 Bio-inspired and biomedical materials; 504 X-ray / Neutron diffraction and scattering; Absorptivity; Antibodies; Blood vessels; Cancer; Chains; Computed tomography; Concentration gradient; Conjugation; contrast agent; Contrast agents; Diagnostic systems; Emission analysis; Focus issue on Nanomedicine molecular science; Gold; Image contrast; Image enhancement; Inductively coupled plasma; Iodine; Low molecular weights; Medical imaging; nanoparticle; Nanoparticles; Optical emission spectroscopy; Polyethylene glycol; tumor; Tumors; X ray absorption; X ray imagery; gold; CT; 504 X-ray / Neutron diffraction and scattering; 30 Bio-inspired and biomedical materials; tumor; nanoparticle; contrast agent
• ISSN: 1468-6996; 1878-5514
• DOI: 10.1080/14686996.2016.1194167

Contrast agents are often used to enhance the contrast of X-ray computed tomography (CT) imaging of tumors to improve diagnostic accuracy. However, because the iodine-based contrast agents currently used in hospitals are of low molecular weight, the agent is rapidly excreted from the kidney or moves to extravascular tissues through the capillary vessels, depending on its concentration gradient. This leads to nonspecific enhancement of contrast images for tissues. Here, we created gold (Au) nanoparticles as a new contrast agent to specifically image tumors with CT using an enhanced permeability and retention (EPR) effect. Au has a higher X-ray absorption coefficient than does iodine. Au nanoparticles were supported with polyethylene glycol (PEG) chains on their surface to increase the blood retention and were conjugated with a cancer-specific antibody via terminal PEG chains. The developed Au nanoparticles were injected into tumor-bearing mice, and the distribution of Au was examined with CT imaging, transmission electron microscopy, and elemental analysis using inductively coupled plasma optical emission spectrometry. The results show that specific localization of the developed Au nanoparticles in the tumor is affected by a slight difference in particle size and enhanced by the conjugation of a specific antibody against the tumor.