Is it possible to couple exopolysaccharides (EPS) from marine bacteria with radioactive scandium isotopes for anti-tumour purposes? Mattia Mazza has been trying to answer this question for three years. He will defend his thesis on 26 March 2021.

Pharmacist and chemist by training, Mattia Mazza began a thesis in December 2017 in the radiochemistry group of the Subatech laboratory and within GIP ARRONAX, under the co-supervision of Sandrine Huclier (Subatech) and Cyrille Alliot (GIP ARRONAX). Aim : to develop the theranostic approach in the treatment of cancers, in particular osteosarcomas, thanks to a better chemical knowledge of exopolysaccharides (EPS) and their interactions with scandium.

Mattia first worked to finely characterise the EPS of interest produced by the marine bacterium Alteromonas infernus : definition of its molecular weight by the AF4-MALS technique, or determination of the conformation by viscosity.  The EPS are produced in a bioreactor and are supplied by the EM3B laboratory (Ifremer, collaboration S. Colliec-Jouault and C. Sinquin). In a second step, the PhD student set out to describe and quantify the interactions of these PSAs with scandium, in order to determine the stability constant. An exploration on the molecular scale was carried out using time-resolved fluorescence spectrometry (TRFS), in collaboration with the CEA Saclay (SEARS, Dr P. Reiller).

Finally, he carried out tests on different cancer cell lines with the aim of observing the cytotoxic effects of EPS-scandium complexes and in particular a synergistic effect of the complexes compared to EPS alone. This work was carried out with the ICO (Tumour heterogeneity and precision medicine laboratory, Pr. D. Heymann).

These EPS-scandium complexes show great promise as theranostic agents, although there is still much to be done.

Contact : Mattia Mazza