Preparation, biodistribution and dosimetry study of Tc-99m labeled N-doped graphene quantum dot nanoparticles as a multimodular radiolabeling agent

A new Tc-99m N-doped graphene quantum dot 99m Tc-(N-GQD) moiety was developed as a radiolabeling agent for molecules lacking chelation or water solubility of ligands simultaneously. (N-GQDs) were synthesized and characterized with high purity (size range = 5-10 nm). After radiolabeling, ITLC demonstrated that the 99m Tc-(N-GQDs) were prepared with high radiochemical purity (RCP ≥ 95%). Filtration of 99m Tc-(N-GQDs) with a 0.1 μm filter proved that 77.38% of the particles were less than 0.1 μm. 99m Tc-(N-GQDs) were injected into healthy Wistar rats for biodistribution studies. Results showed that 99m Tc-(N-GQDs) were eliminated by the kidneys, and accumulated in the spleen due to the particle size of 99m Tc-(N-GQDs). The ovaries and uterus showed a greater concentration of 99m Tc-(N-GQDs) within 2 h after injection compared with other organs. Dosimetry studies were done to find out the effective radiation dose of each organ, and introduced the kidneys as critical organs. This research has demonstrated the profound feasible production of 99m Tc-(N-GQDs) for possible radiolabeling of molecules with chelation limitations and poor water solubility. Preparation, dosimetry and biodistribution study of 99m Tc-(N-GQDs) as multipurpose nanoparticles.