Magnetic resonance imaging of mesenchymal stem cell – migration towards glioblastoma using a nano-calcium phosphate contrast agent

Tracking stem cell homing to the brain, their infiltration and brain tissue distribution, are critical for evaluating the efficacy of stem cell-based anti-glioma therapy. Here, we report the use of a biomineral magnetic nano-contrast agent, Fe-doped calcium phosphate nanoparticles (nCP:Fe), to label mesenchymal stem cells (MSCs) and track their migration towards brain tumor using magnetic resonance imaging (MRI). nCP:Fe labelled MSCs implanted intra-ventricularly in a rat C6-glioma model showed longitudinal migration towards tumor-region over 14 days, detected as hypointense signals in T2/T2* weighted-MR images, which was confirmed ex vivo using histological staining. Although, a small fraction of implanted MSCs migrated to the tumor-site, the study demonstrates that, MRI tracking of stem cells using nCP:Fe nano-contrast agent will facilitate better assessment of the efficacy of stem cell-guided anti-tumor therapy.