Current research topics mainly concern the preparation of molecular and nanostructured hybrid systems, for applications in biomimetic catalysis, green chemistry and nanomedicine.

1) Design of bio-hybrid polyoxometalates (POMs) with pharmacological activity

Polyoxometalates (POMs) are molecular metal oxides of early series transition metals as Mo, W, V in their highest oxidation state. POMs have a large structural topology and a rich versatility of chemical and physical properties. The POMs, indeed, find application in catalysis, materials science and as potential nano drugs, since they display antiviral, antibacterial, neuroprotective and anticancer activity. Their biological activity is mainly due to the alteration of the redox processes of the cell and to the ability to interact with biological macromolecules (proteins and enzymes) containing cationic groups. A limit to their use is the low selectivity; for this reason, studies are underway to functionalize these compounds with organic-type molecules, in order to make POMs more selective.

The project therefore plans to study the interaction between POM and biological molecules, and to optimize the preparation of bio-inorganic hybrid derivatives. In particular, the following steps are under study:
(i) the covalent functionalization of molybdates and vanadates featuring antitumor activity, with peptides and other bio-molecules suitable for molecular recognition of biochemical targets;
(ii) recognition of peptides and proteins involved in diseases such as cancer and Alzheimer's disease, to highlight the inhibitory abilities of polyoxotungstates;
(iii) the preparation of delivery systems (capsules and nanotubes).

The planned work consists in the synthesis of hybrid derivatives (NMR characterization, ESI-MS, optical spectroscopy) and in the study of interactions with proteins (UV-vis, CD, Fluorimetry, 2D NMR). The proposal involves collaborations in the field of synthesis and characterization of peptides or proteins. The implementation of cytotoxicity tests at other institutions is also planned.


2) Circular chemistry: valorization of waste materials

Multinuclear metal comoplexes can be employed as environmentally benign acid (or oxidation catalysts) in the synthesis of chemicals and fuels from renewable feedstocks or industrial /agricoltural wastes. However, these reactions invariably suffer from extensive formation of by-products and require further optimization and engineering. For example, rehydration reactions, degradation and condensation can affect the efficiency of such transformations.
An intriguing possibility to make polynuclear catalysts more efficient as well as heterogeneous is to cross-link them into organic polymers (A) or support onto functionalized clay nanotubes (B).
Synergistic properties will spring from the merging of the two domains, with the support enabling the selection of the substrate to be transformed, owing to adsorption, porosity, swelling. The proposal objectives are to explore the use of innovative nano-catalysts for the valorization of renewable materials.

These goals will be pursued by combining the use of green solvents (such as dimethyl carbonate, limonene, ethyl lactate, water and ionic liquids, deep eutectic solvents). The composite polymers will be characterized by ATR, TGA, SEM, physisorption (BET). The reactions will be screened , optimized and studied from a mechanistic point of view, upon monitoring by GC-MS, GC, HPLC, and H-NMR.