Stacey M. Cromer Berman1, Kshitiz Gupta2, C. Joanne Wang2, Inema Orukari1, Andre Levchenko2, Piotr Walczak1, Jeff W.M. Bulte1
1Dept. of Radiology, Johns Hopkins University, Baltimore, MD, United States; 2Dept. of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States
Time-lapse microscopy of cell division and random cellular motility assays were performed on SPIO-labeled neural stem cells. Both the maximum and average speed of NSCs were reduced as compared to unlabeled controls. Following transplantation into mouse brain, rapid exocytosis of SPIO by live (as determined by BLI) cells was observed as early as 48 hours post-engraftment, with SPIO-depleted cells showing the farthest migration distance. As label dilution is negligible at this early time point, we conclude that MRI underestimation of cell migration can occur as a result of reduced cell motility, which is mitigated following SPIO exocytosis.