MR imaging provides information on myocardial viability, microvascular obstruction and real time imaging to guide minimally invasive intramyocardial injection of new therapies. MR contrast media and MR cell labeling allow assessment of myocardial viability and treatment effectiveness. Thus, they open up new avenues in molecular and cellular imaging.

The modification of lipoproteins, mainly LDL and HDL, with radioisotopes for nuclear imaging, gadolinium chelates for magnetic resonance imaging, or other possible contrast agents for computed tomography, has helped to detect and characterize the atherosclerotic lesion. These specific contrast agents may enable initiation of therapy for atherosclerotic lesions prior to their becoming symptomatic.

MTS-ADO3A is a new complexing agent of Gd(III) featuring a methanethiosulfonate group that readily reacts with thiol groups on native or reduced albumin and on thiolated silica particles. Its synthesis and relaxivity properties are reported. The isolated conjugates with albumin and particles display high relaxivity increases that remain limited by slow water exchange as shown by ¹⁷O NMR and NMRD. The reactivity of the disulfide bonds in presence of thiol derivatives has been investigated.

Phenylboronate funcionalized Ln(III)–DTPA complexes recognize sialic acid (Sia) on tumor cells. The cell recognition occurs by means of covalent binding between PBA and the diol-function of Sia and is assisted by an electrostatic interaction between an ammonium group and the negatively charged cell surface.

Intracellular MR contrast agents were developed, which conjugated PNA with cell-penetrating peptides, Gd-DOTA and FITC, respectively. Their intracellular delivery ability was demonstrated by cell biological tests labeling cells for MR and fluorescent optical imaging.

A temperature-sensitive MRI contrast mechanism is proposed based on the Curie temperature (T_c)—at which a ferromagnetic material transitions to paramagnetic state. In this study, magnetic susceptibility artifact area on MRI caused by pure, solid gadolinium (Gd) decreased with increasing temperature around T_c (20 °C) for Gd (p < 0.05). Potential applications of this mechanism may include MR thermometry and thermotherapy monitoring, using materials or alloys with desired T_c and magnetic susceptibility artifact versus temperature curves.

Lanthanide-based magnetization transfer (PARACEST) contrast agents offer great potential for probing physiological processes by magnetic resonance imaging (MRI). The versatility of these novel agents can be further augmented by introducing functionality that allows covalent attachment of the agent to biotargeting vectors for site specific and molecular imaging applications. The synthesis and CEST profile of a bifunctional PARACEST intermediate being developed for targeted nanoparticle applications is reported herein.