MR tracking of transplanted glial cells using poly-l-lysine-CF3

Magnetic resonance (MR) imaging using super-paramagnetic iron oxides (SPIOs) is a powerful tool to monitor transplanted cells in living animals. Since, however, SPIOs are negative contrast agents, positive agents have been explored. In this study, we examined the feasibility of FITC-labeled poly-l-lysine-CF3 (PLK-CF3) using glial cells. FITC-labeled PLK-CF3 was easily internalized by neuroblastoma cells and glia as adding it into culture medium. No toxicity was seen at the concentration of less than 80 μg/ml. MR images positively detected labeled cells transplanted in the brain of living mouse. The results indicate that FITC-labeled PLK-CF3 is a useful positive contrast agent for MR tracking.