Repurposing iron chelators for accurate positron emission tomography imaging tracking of radiometal-labeled cell transplants

The use of radiolabeled cells for positron emission tomography (PET) imaging tracking has been a promising approach for monitoring cell-based therapies. However, the presence of free radionuclides released from dead cells during tracking can interfere with the signal from living cells, leading to inaccurate results. In this study, the effectiveness of the iron chelators deferoxamine (DFO) and deferiprone in removing free radionuclides Zr-89 and Ga-68, respectively, was demonstrated in vivo utilizing PET imaging. The use of DFO during PET imaging tracking of Zr-89-labeled mesenchymal stem cells (MSCs) significantly reduced uptake in bone while preserving uptake in major organs, resulting in more accurate and reliable tracking. Furthermore, the clearance of free Zr-89 in vivo resulted in a significant reduction in radiation dose from Zr-89-labeled MSCs. Additionally, the avoidance of free radionuclide accumulation in bone allowed for more precise observation of the homing process and persistence during bone marrow transplantation. The efficacy and safety of this solution suggest this finding has potential for widespread use in imaging tracking studies involving various cells. Moreover, since this method employed iron chelator drugs in clinical use, which makes it is a good prospect for clinical translation.