Evaluation of glyco-saccharides in a theranostic approach ; Evaluation de glyco-saccharides dans une approche théranostique

Osteosarcoma is the most common primary malignant bone tumor in children and young adults. It is a very aggressive type of cancer with a low prognosis; but molecular mechanism of metastases have been identified for designing new therapeutic strategies in the frame of personalized medicine. Among the biomarkers considered, glycoaminoglycans (GAGs) are a hallmark related with cancer growth and spread. GAGs could be employed in new drug delivery systems to deliver active compounds for therapeutic uses. A theranostics approach, i.e. combination of apredictive biomarker with a therapeutic agent, has been developed in this work. Firstly, because GAGs have antimetastatic properties and especially exopolysaccharides produced by a marine bacteria Alteromonas infernus. Additionally, a true theranostic pair of radionuclides has been considered, namely the scandium isotopes 44Sc/47Sc. Thus, GAGscould act in synergy with radionuclides of interest for NuclearMedicine and the goal of this work was to evaluate the feasibility of coupling EPS with Sc. The characteristics related to the applicability of these EPS in theranostics have been studied, for example the rheological behavior of the polymers. This stability depends on the chemical composition of the suspensions, but also on the size and size distribution of the molecules and their surface charge. This work presents the characterization tools that allow studying these properties. The methodology developed has been used to ensure the control of the composition, size, shape and surface characteristics of the EPS for further potential in vivo injections. The second objectiveof this work is to reach to the most comprehensive description of the interaction of these EPS with scandium. However, each metal is unique and is defined by its oxidation state, coordination number, hard‐soft characteristics, kinetic inertness or lability, and redox stability. Therefore, the particular coordination chemistry of scandium to these EPS has been accurately studied. Finally, the biological ...