Lanthanide Containing Systems for Molecular Magnetic Resonance Imaging and Therapy

Abstract

Magnetic resonance imaging (MRI) is one of the most powerful imaging tools due to its very high resolution and the possibility of imaging the whole body. Its lack of sensitivity can be compensated for by the use of a contrast agent (CA), typically Gd3+-based complexes. Since most of the commercially available Gd3+-based CAs have no specificity, research in the area of molecular imaging (i.e. biomarkers detection) has been the subject of growing interest in the past decades. This leads to the design of more powerful CAs, which should enable early detection of disease and personalised medicine. In the first part of this chapter, recent advances in the detection of endogenous triggers (pH, cations, enzymes) will be described. In the second part, we will focus on the design of targeted CAs to detect deregulated proteins or receptors. Finally, we will concentrate on theranostics, i.e. combining an imaging technique with therapy. This offers endless possibilities for monitoring treatment efficacy in real-time or in the follow-up of therapies. The combination of MRI with different therapies (chemotherapy, photodynamic therapy and radiation therapy) will be described. Rather than an exhaustive review of each topic, this chapter aims at describing the state-of-the-art of the different methods with selected examples, together with strengths and limitations of those CAs.