摘要：SummaryA major unresolved challenge in cell-based regenerative medicine is the absence of non-invasive technologies for tracking cell fate in deep tissue and with high spatial resolution over an extended interval. MRI is highly suited for this task, but current methods fail to provide longitudinal monitoring or high sensitivity, or both. In this study, we fill this technological gap with the first discovery and demonstration ofin vivocellular production of endogenous bright contrast via an MRI genetic reporter system that forms manganese-ferritin nanoparticles. We demonstrate this technology in human embryonic kidney cells genetically modified to stably overexpress ferritin and show that, in the presence of manganese, these cells produce far greater contrast than conventional ferritin overexpression with iron or manganese-permeable cells. In living mice, diffusely implanted bright-ferritin cells produce the highest and most sustained contrast in skeletal muscle. The bright-ferritin platform has potential for on-demand, longitudinal, and sensitive cell trackingin vivo.Graphical AbstractDisplay OmittedHighlights•First bright-ferritin MRI gene reporter platform for longitudinal cell tracking•In vivoassembly of manganese nanoparticles for bright MRI contrast•On-demand, sensitive, non-invasivein vivodeep imaging of proliferating cellsMedical Imaging; Technical Aspects of Cell Biology; Nanomaterials
