A highly sensitive nanoparticle imaging agent for tracking the migration of dendritic cells to lymph nodes has been developed
Prof. Dong-kwon Lim has his article published in NPG Asia Materials

Prof. Dong-kwon Lim from the KU-KIST Graduate School of Converging Science and Technology, working together with Prof. Jae-tae Lee from the Daegu-Gyeongbuk Medical Innovation Foundation, Prof. Yong-hyun Jeon from the Kyungpook National University Hospital, and Prof. Hwan-Jeong Jeong from the Chonbuk National University Hospital, developed nanoparticles as a highly sensitive and stable nuclear and optical imaging agent based on radioisotopes. The finding enables an extremely small dose of nanoparticles to function as an imaging agent for tracking the migration of dendritic cells, which can induce antitumor immunity, to lymph nodes.

* Dendritic cell: One of the antigen-presenting cells in the immune system. It has veil-like membrane protrusions, as in the case of the dendrites of neurons. It recognizes abnormal cells such as a tumor or those infected by bacteria or a virus and feeds related information to the body's T cells, thus inducing them to attack the abnormalities in the immune system.

Their research results were published in NPG Asia Materials online on June 17. NPG Asia Materials is a globally renowned scientific journal published by the Nature Publishing Group. (Citation for the article: Radionuclide-embedded gold nanoparticles for enhanced dendritic cell-based cancer immunotherapy, sensitive and quantitative tracking of dendritic cells with PET and Cerenkov luminescence, NPG Asia Materials (2016) 8, e281; doi:10.1038/am.2016.80)

The research team examined the conjugation properties of hundreds of short DNA sequences, in particular the chemical reaction of adenine-rich oligonucleotide sequences on gold nanoparticles, which allowed the conjugation of thousands of radioisotopes per gold nanoparticle. Furthermore, the team formed an additional gold shell on the surface of the gold nanoparticle to greatly improve the in vivo stability of the radiolabeled DNA on the gold nanoparticles, thus developing a highly sensitive and reliable imaging agent. The agent released strong radioactive signals, even in a very low concentration of water (molar concentration 10-12), showing a strong Cerenkov effect. In particular, when dendritic cells labeled with radionuclide-embedded gold nanoparticles were injected into mice, PET/CT imaging demonstrated the highly selective migration of the labeled dendritic cells to lymph nodes as early as 6 hours post injection and continuing to day 4.

The research results suggest that a sensitive and quantitative tracking of the migration, distribution and movement of immune cells is possible, which is essential in assessing the effect of cancer treatments based on antitumor immunity. In particular, on top of the tracking function, the imaging agent can be useful in detecting an extremely small cancer tissue or an infection area in their early stages.

“The fusion research that applies intuitive understanding on the synthetic chemistry of nanoparticles to medicine can contribute to tackling existing medical challenges, and I hope that we can apply these findings to the actual medical field by gradually expanding their applications,” said Prof. Lim