Engineering of Radioiodine-Labeled Gold Core-Shell Nanoparticles As Efficient Nuclear Medicine Imaging Agents for Trafficking of Dendritic Cells

The development of highly sensitive, stable, and biocompatible imaging agents allowing visualization of dendritic cell (DC) migration is one of the essential factors for effective DC-based immunotherapy. Here, we used a novel and efficient synthesis approach to develop radioiodine-124-labeled tannic acid gold core-shell nanoparticles (¹²⁴I-TA-Au@AuNPs) for DC labeling and in vivo tracking of their migration using positron emission tomography (PET). ¹²⁴I-TA-Au@AuNPs were produced within 40 min in high yield via straightforward tannic acid-mediated radiolabeling chemistry and incorporation of Au shell, which resulted in high radio-sensitivity and excellent chemical stability of nanoparticles in DCs and living mice. ¹²⁴I-TA-Au@AuNPs demonstrated good DC labeling efficiency and did not affect cell biological functions, including proliferation and phenotype marker expression. Importantly, ¹²⁴I-TA-Au@AuNPs in an extremely low amount (0.1 mg/kg) were successfully applied to track the migration of DCs to lymphoid organs (draining lymph nodes) in mice.