Smart Organic Nanostructures against Neurological Diseases

This thesis mainly focuses on some problems related to the central nervous system. For this purpose, different types of smart organic nanostructures were developed and tested on the different cell lines necessary for the relevant applications. In the first part, novel lipid-based magnetic nanovectors were proposed for an effective treatment of glioblastoma multiforme (GBM), which is the most aggressive brain tumor that originates from glial cells. The median survival rate of GBM patients is approximately 16.9 months and less than 5% of patients can live longer than 5 years due to nearly 90% recurrence rates. Superparamagnetic iron oxide nanoparticles (SPIONs) with an effective coating/functionalization can be targeted to tumor cells and induce local magnetic hyperthermia upon alternating magnetic field (AMF) stimulation. Coating the surface of SPIONs with lipids has many advantages, such as increasing the ability to cross the blood-brain barrier for brain tumor targeting, enabling surface modification to achieve the desired targeting and loading of chemotherapeutic drugs to benefit from the synergic therapeutic effect of hyperthermia and chemotherapy. In the first chapter, SPIONs were incorporated into sphingomyelin, a phospholipid found in cell membranes and derived from the porcine brain, along with a chemotherapeutic drug, regorafenib. The magnetic properties of these nanostructures were studied under AMF stimulation. The combined effect of lipid magnetic nanovectors (LMNVs) loaded with regorafenib (Reg-LMNVs) was tested in vitro on the glioblastoma cell line (U-87 MG). Promising results demonstrated that LMNVs induced mild hyperthermia and anticancer effects (characterized by the reduction of the proliferation rate and expression of heat shock proteins such as HSP70) against U87 MG cells. In Chapter 2, previously developed lipid-based magnetic nanovectors coated with the cell membrane (CM), extracted from GBM patient cells, were analyzed by Raman spectroscopy. The effect of extraction and/or coating procedures on the conformation of proteins was studied by comparing the specific Raman bands of proteins. A minor effect, possibly on the proteins facing the nanoparticle surface, was observed. Also, the internalization of the same particles by 2D GBM patient cells was studied by Synchrotron X-ray Fluorescence (XRF) microscopy. In Chapter 3, Confocal Raman microscopy (CRM) was proposed as a useful tool for studying nanoparticle internalization. Raman bands of two different nanoparticles were characterized and then used to detect the particles within fibroblast cells. The last chapter of the thesis is dedicated to an ongoing Agenzia Spaziale Italiana (ASI) – Istituto Italiano di Tecnologia (IIT) project. This work was based on novel lipid-coated polydopamine nanoparticles (L-PDNPs), which were proposed in a previous study. L-PDNPs are promising nanostructures in terms of providing catecholaminergic support for neurons and protecting them from oxidative stress. They were proposed as protective countermeasures against oxidative stress (OS) induced by microgravity (MG) and cosmic radiation (CR) during spaceflights. The nanoparticles were tested on neuron-like SH-SY5Y cell line in space conditions, to study their possible protective and supportive effects on the central nervous system (CNS) which is a vulnerable target of oxidative stress. Several experiments were carried out autonomously at the International Space Station (ISS) to better comprehend the negative effects of MG and CR and the protective effect of L-PDNPs. The samples were then prepared for transcriptional analysis to investigate the expression of particular markers related to antioxidant defense, nuclear integrity, mitochondrial respiration, and dopamine metabolism and secretion.