Synthesis and characterization of new hybrids nanomaterials for biomedical applications ; Synthèse et caractérisation de nanomatériaux hybrides innovants pour le biomédical

From decades now, nanomaterials and especially superparamagnetic iron oxide nanoparticles are studied for their numerous applications in nanomedecine area. The biocompatibility and the magnetic properties of such nano-objects allow their utilization for diagnostic (MRI, optical imagery, PET…) and for therapy application (nanovectorization, hyperthermia…) During this thesis work, the first step was to study the influence of several synthesis parameters on the final properties of the magnetic iron oxide nanoparticles. The aim of this study was the development and the optimization of the widely used way of synthesis by co-precipitation modified by a ligand addition during the growth step of the synthesis. Citrate capped iron oxide nanoparticles with a controlled size between 4 and 13 nm have been synthesized, the saturation magnetization of these nanoparticles reach 75 emu/g of iron oxide, this value is particularly high for nanoparticles of such sizes. During this work, the large panel of characterizations performed on these nanoparticles (TEM, XRD, Mössbauer, FTIR, XPS, DLS, Magnetic measurement) allowed to study precisely the relations between size, ligand ratio, composition and magnetic properties of the synthesized nanoparticles. The interaction between the synthesized citrate capped nanoparticles and biological materials such as human cells have been investigated in-vitro notably to evaluate cells internalization and citotoxicity. In a second step, some additional works have been performed on the citrate capped iron oxide nanoparticles in order to replace the citrate ligand by a bio-inspired polymer (poly-oxazoline). This polymer can have multiple biomedical applications depending of the pendent chemical groups that have been fixed on it ; Depuis quelques décennies, les nanomatériaux et tout particulièrement les nanoparticules d’oxyde de fer (magnétite/maghémite) superparamagnétiques ont connus un intérêt croissant en nano-médecine. Leur biocompatibilité et leurs propriétés magnétiques permettent notamment ...