Photoactive tools for biomedical applications. From supramolecules to micro-objects

The research work within the wide field of nanomedicine that is presented in this thesis is centred on the development of new nanostructured multifunctional materials for future theranostic applications. In Chapter 2, is presented a new luminescent chemosensor for Mg2+ detection in mitochondria based on a diaza-18-crown-6 appended with two 8-hydroxyquinoline(8-HQ) derivative. In Chapter 3 is reported a new synthetic strategy, to prepare silica core/PEG shell nanoparticles doped with phosphorescent emitters such as organic molecules called “asterisks” and metal-phorphyrins. In Chapter 4 will be shown the study carried out at the New York University, centred on the synthesis of microstructures suitable to mimic invading microbial pathogens. There were also prepared other active colloids able to be propelled by the oxygen bubbles formed by a chemical reaction that is UV-light activated in the presence of hydrogen peroxide. Chapter 5 will deal with bioresorbable electrospun nanofiber mat that, if doped with theranostic agents can be used to the release the active species, during their degradation after post-surgical implantation. Photophysical characterization is reported together with a study of the PLGA fibers degradation that proves that the nanoparticle release correlates very well with the degradation profile in physiological conditions. Chapter 6 merged some research works on different species that could have, interesting properties to be exploited in building block moieties for the design of multifunctional platforms. The attention has been focused on NIR emitters. It has been discussed the results obtained with rhenium(I) and lanthanide metal complex from a photophysical point of view both in solution and in the solid state. Is also presented a basic study that aims to assess the possible pro-oxidant or antioxidant effects induced by gold nanoparticles.