Design and study of multifunctional systems based on magnetic nanoparticles for biomedical applications

Resumo

Nanomedicine is a new field employing nanotechnology tools for biomedical applications. Nanomaterials feature sizes between 1 and 100 hundred nanometers, and therefore they fill the gap between single molecules and bulk materials. They open the possibility to access biological processes on the same size scale. Nanoparticles have shown great potential to achieve the goal of personalized medicine due to the possibilities to modify their surface with proteins, targeting molecules, or imaging probes. Particularly, iron oxide nanoparticles show promising properties for successful application in biomedicine due to their low-cost production, high biocompatibility, and great magnetic response. Strategies for the functionalization of inorganic cores have been developed over the past years, and efforts have been devoted to engineering nanoparticles with multifunctional ligands on the surface to enable active tumor targeting, detection over different imaging modalities, and stimulus-driven cargo release. During this Ph.D. thesis, three main aspects of iron oxide nanoparticles have been evaluated. First, the stability of nanoparticles has been addressed in biological fluids. Second, the uptake of nanoparticles by stem cells for cell tracking applications was studied with nanoparticles of different sizes and bearing different organic coatings. Third, new possibilities of chemical functionalization of naked iron oxide nanoparticles by orthogonal processes have been explored, in order to achieve high yields, simplicity and high reproducibility.