Targeted Nanoparticles for synergistic drug delivery to Multiple Myeloma

In the latest years, nanomedicine has gained immense attention, providing promising and innovative therapeutic strategies. This is particularly true for nanosystems employed in cancer treatment, by virtue of the small size of devices and their easily tunable physical and morphological properties, which allow effective interactions at a molecular level with cells. In the present Master Thesis, the purpose is to develop a biomimetic protocell, namely a drug-loaded nanosystem which, thanks to its surface functionalization, is capable to selectively address, be internalized and kill cancer cells, avoiding the typical side-effects associated with conventional therapies. The nanoconstructs are specifically designed to target Multiple Myeloma (MM). In particular, they were designed with a Mesoporous Silica Nanoparticle (MSN) core, which is covered with a self-assembled lipidic double layer (shell), necessary to enhance biostability and functionalization. Mesoporous silica is a highly biocompatible material, and it is characterized by a huge specific surface area (approximately 1000 m2/g) which allows to encapsulate a great amount of drug molecules. In this project, the MSNs were synthetized using a template-assisted sol-gel self-assembly process, obtaining 40-50 nm sized nanoparticles and a mesoporous structure characterized by cylindrical and uniform (3-4 nm) pores. The mesoporous structure was exploited to adsorb and encapsulate a highly water-insoluble drug, AGI-6780, otherwise impossible to administer due to its great hydrophobicity and extremely poor biodistribution properties. AGI-6780 is not lethal for the cells itself; however, it was proved to synergize with Carfilzomib (CFZ), a common chemotherapeutic drug currently used in clinics, to which patients often develop resistance. In this Master Thesis, strong effort was made in relation to drug loading, trying to enhance drug loading efficiency with different uptake solutions and concentrations. Another crucial step was the decoration of the surface of the nanocarrier with antibody fragments. Since MM cancer cells overexpress CD38 receptor, anti-CD38 monoclonal antibody was chosen for functionalization, allowing a highly specific and selective interaction between MM cells and NPs. Different antibody-lipids coupling methods were tested and qualitatively evaluated by means of fluorescence microscopy. The therapeutic efficacy of the developed nanoconstructs and contextually the synergy between AGI-6870-loaded MSNs and CFZ were tested on a Human Multiple Myeloma cell line by Molecular Biotechnology Center (MBC, University of Turin).