Research Interests

Development and multinuclear NMR characterization in solution of paramagnetic metal complex as diagnostic probes The goal is the understanding of the chemical properties of MRI contrast agents (GdIII, MnII, FeIII chelates) and the dependence of their effectiveness (relaxivity) from the molecular parameters. These include: i) the factors that control the rate of exchange of coordinated water molecules; ii) the presence in solution of various diastereoisomers, and of hydration equilibria; iii) the dominant contribution of the rotational dynamics to relaxivity, and thus the different strategies to slow down molecular motion; iv) the role of the second sphere of hydration.
Synthesis and characterization of multi-functional inorganic nanoparticles
Various nanosystems are developed in which multiple paramagnetic complexes are conjugated to platforms of various nature, size and complexity. These MRI nanoprobes make it possible to deliver to the site of interest a large number of paramagnetic ions, thus increasing the sensitivity of the MRI modality. The systems include protein−bound chelates, polymers, dendrimers, micelles, liposomes, viral capsids, metal oxides, zeolites, mesoporous silicas. Desired properties are high imaging contrast and chemical stability, target specificity, and/or multimodality.
Development of multimeric systems as high field MRI probes
The increasing availability of high field MRI systems requires a different strategy for relaxivity enhancement of metal-based probes. In our approach, we seek: a) chemical control of the value of the rotational correlation time (ca. 0.2 − 0.5 ns), corresponding to that of small multimeric systems; b) sufficiently fast rate of water exchange (τM ≤ 100 ns); c) large contribution to relaxivity from water molecules in the second coordination sphere. This contribution can be very significant as it can provide about 30-40% of the global relaxation enhancement.
Study of the structural and dynamic properties of complexes and macromolecules containing paramagnetic ions with NMR fast field cycling relaxometric techniques
Relaxometry is the measurement of the frequency dependence of magnetic relaxation rates of solvent nuclei in aqueous systems to extract structural and dynamic information on the nature of the solutes. We apply the technique to the study of detailed physico-chemical properties of complexes of trivalent lanthanoids in order to obtain information about the changes that take place across the series, on the nature of the relaxation processes and their dependence on pH, and temperature, on self-recognition mechanisms, on the reversible formation of macromolecular adducts.