Detection of enzymatic activity by PARACEST MRI: a general approach to target a large variety of enzymes
Résumé
We report a new family of molecular imaging probes that offer the possibility of specific PARACEST (paramagnetic chemical exchange saturation transfer) MRI detection of a large variety of enzymatic activities. The probes are based on a lanthanide complex coupled to an enzyme-specific substrate through a self-immolative spacer. Upon enzymatic cleavage of the substrate, the spacer is spontaneously eliminated, thereby resulting in a remarkable change in the PARACEST properties of the Ln3+ chelate. This new type of contrast agent opens up new perspectives in molecular magnetic resonance imaging.