Targeting of Tumor Cells with Glutamine Containing Carriers

Introduction: In respect to other molecular imaging modalities the low sensitivity is the main limitation of the MagneticResonance-Molecular-Imaging approach. Therefore, the success of a MR-Molecular Imaging protocol strongly relies on the amplification effects associated to the accumulation of the agents at the cells of interest. Efficient routes to accumulate imaging probes in tumor cells may be found by exploiting the up-regulation of trans-membrane transporting systems. In fact, rapidly growing tumors require an increased and continuous supply of aminoacids and other nutrients. Glutamine appears an interesting candidate as it is considered the main source of nitrogen for tumor cells. Thus tumor cells have been targeted with MR imaging probes bearing glutamine residues as targeting vectors.