The objective of this thesis was the preparation ofbiocompatible hydrophilic functionalized polymers forthe stabilization and bio-functionalization of iron oxidenanoparticles (IONPs) for biomedical applications suchas contrast agents in magnetic resonance imagingand/or targeted drug delivery. In this work, commerciallyavailable poly(ethylene oxide)s (PEO), which havehydrophilic, biocompatibility and furtivity properties havebeen functionalized by a phosphonic acid group, thatstrong anchors on IONPs, and by a furan group that canbe coupled to maleimide-terminated biomolecules by athermoreversible Diels-Alder reaction.Phosphonic acid-terminated PEOs fonctionalized by afurane group were synthesized according to two originalstrategies combining an Atherton-Todd or a Kabachnik-Fields reaction and a 1,3-dipolar cycloaddition reaction.This latter reaction, also named ‘click’ reaction, ischaracterized by high yields, simple reaction conditions,fast reaction times, and high selectivity.These PEOs were attached to the IONPs surface usingthe 'grafting onto' strategy. The subsequent polymerstabilizedIONPs were characterized, proving thepresence of polymers on IONPs surfaces. Cytotoxicitystudies revealed that the IONPs carriers werebiocompatible. In addition, studies on the protontransverse relaxation enhancement properties of thesestabilized IONPs indicated high relaxivities in the samerange as iron oxide based commercially availablecontrast agents. Finally, polymer-stabilized IONPs weresuccessfully functionalized by maleimide-functionalizedmolecules according to the Diels-Alder reaction and thesubsequent release of these molecules via a thermalstimulus has been proven. Consequently, this type ofcontrolled-release system could be expanded to drugtherapy responding to external stimuli.
Poly(oxyde d'éthylène)s fonctionnels à extrémité acide phosphonique et à fonctionnalité réversible pour la stabilisation de nanoparticules magnétiques