Highly Paramagnetic Tumor-Targeted Contrast Agents

The noninvasive imaging of cell surface markers could provide a powerful technique for the early identification of cancer as well as allow for repetitive measurements to monitor the efficacy of therapeutic treatments. Magnetic resonance (MR) is a particularly attractive platform for molecular imaging due to the ability to acquire high-resolution anatomical images in conjunction with measures of biomarker expression; however, the sensitivity of MR contrast agents is often too low to detect the relatively low number of cell receptors per imaging voxel at the targeted site. To generate the level of sensitivity required for imaging molecular markers of disease, novel approaches must be established to amplify the MR signal. In this talk, we will describe how nanoparticulate carriers can be designed to carry extremely high gadolinium (Gd) payloads in order to compensate for the low MR signal enhancement generated by individual Gd ions. Further, we will show that Gd-labeled nanoparticles that have been functionalized with targeting ligands can be used for the highly sensitive detection of human tumor xenografts in mice.