Σύνθεση νέων σκιαγραφικών μέσων απιειόνισης μαγνητικού συντονισμού με ιδιότητες εκλεκτικής πρόσληψης από συγκεκριμένου τύπου κύτταρα

Abstract

In the first part of the particular study, a series of nanohybrid materials was prepared, which has present characteristic magnetic, chemical and biological properties. These nanohybrids were appropriately designed for biomedical applications such as magnetic resonance imaging (MRI) and neutron capture therapy (NCT). Double layered hydroxides (LDH) were the base of our synthesis, preparing a variety of different types, after the introduction of paramagnetic elements in the inorganic framework. The change-overs of lanthanide ions allow the preparation of two completely disparate materials, Gd2(OH)5NO3 and Gd(OH)3. Gd2(OH)5NO3 consist of a new class of anion exchangeable layered hydroxides incorporating gadolinium cations within the layers. This material has the potential to combine the properties of the lanthanides with the flexibility of intercalation hosts. The surface of Gd2(OH)5NO3 was modified in order to obtain water solubility, functionalization and the ability to target cancer cells. This was achieved by covalent bonding of folic acid or biotin on the surface of Gd2(OH)5NO3. In addition, a variety of molecules, were intercalated in Gd2(OH)5NO3, such as the antibiotic nalidic acid, the aminoacids aspartate and glutamate as well as the fatty acid palmitic acid. Gd(OH)3 was prepared during a variation of the above synthesis. Gd(OH)3 is consisted of bundle-like nanorods and has numerous applications in science and technology, due to its special optical, electrical and chemical properties. In order to produce a biocompatible material, a poly-lactate layer was developed. Furthermore, the aminoacid tryptophan was covalent bonded on the surface of the particles. Experiments show that these materials did not present toxicity towards to the bacterium E.coli and the Sacharomyces Cerivisae. Apart from that they present a meaningful increase of proton relaxivity and are considered to be promising particles for proportional purposes. The above nanohybrids were characterized by using X-ray diffraction, infrared spectroscopy, ultraviolet-visible spectroscopy, magnetic measurements, TEM, HRTEM and SEM microscopy as well as thermogravimetric analysis. In the second part of this study, is mentioned the immobilization of GOx on the surface of silica MCM-41 and the extensive characterization of the immobilized 4 enzymes. The nanohybrid was characterized by using X-ray diffraction, infrared spectroscopy, TEM microscopy as well as thermogravimetric analysis. Eventually, immobilized GOx was used for the development of a glucose biosensor