Synthesis and in Vitro Evaluation of a Biotinylated Dextran-Derived Probe for Molecular Imaging

Herein we report the design, synthesis, and in vitro evaluation of a gadolinium-containing biotinylated dextran-derived mole­cular imaging probe as a prospective neuroanatomical tracer by means of magnetic resonance imaging (MRI). The probe was effectively taken up by cultured differentiated murine neuroblastoma cells and significantly enhanced the contrast in T₁- and T₂-weighted MR images of labeled cells under physiological conditions. A significant longitudinal relaxation rate enhancement in the presence of avidin was observed allowing the verification of the results in the end of noninvasive longitudinal MRI connectivity studies by post-mortem histology. The in vitro results indicate that the probe has the potential to be used in vivo to identify the organization of global neuronal networks in the brain with MRI.