Digital Theses Archive


Tesi etd-03222022-162727

Type of thesis
Innovative drugs against degenerative disease: Applications for Earth and space biomedicine
Scientific disciplinary sector
Istituto di Biorobotica - BIOROBOTICS
Relatore Prof. DARIO, PAOLO
  • antioxidant
  • Blood-brain barrier
  • nanoparticles
  • oxidative stress
  • planarians
  • space biology
  • thyronamines
  • zebrafish
Exam session start date
This PhD thesis presents the results of the study, in vitro and in vivo, of innovative nanostructured compounds for the treatment of degenerative diseases, both on the Earth and in the context of medicine applied to space exploration. The thesis is therefore divided into two sections: the former focusing on cellular biology, the latter on space biology.<br>In particular, the first section tackles the theme of the blood-brain barrier (BBB) crossing, a complex of vessels and several different cell types with the fundamental function of protecting the central nervous system (CNS) from pathogens and neurotoxic agents. At the same time, it regulates the homeostasis and the exchange of nutrients between the nerve cells and the blood. However, it usually renders drug treatments difficult, either hampering drug entry or favouring its release before it has time to solve its pharmaceutical activity. Specifically, in this section is presented a study where we reproduced an in vitro system mimicking blood-brain barrier structure and functions. The crossing capability of two compounds, T1AM and TA1 was evaluated, aiming to estimate their possible use in the prevention and treatment of central nervous system disorders. These compounds have, indeed, a proven neuroprotective effect.<br>Among the illnesses affecting the brain, there is the glioblastoma multiforme (GBM), a malignant tumour hard to treat because it is often impossible to reach in a surgical procedure or completely remove it. Other factors contributing to an unfavourable prognosis are resistance to chemo- and radiotherapy, leading to relapses. For this reason, in the last section, the effect of the drug nutlin 3a was studied on three different cell lines. Moreover, nutlin 3a was encapsulated in piezoelectric nanoparticles, with the aim not only to increase drug cellular uptake but also to amplify its therapeutic effects through ultrasound stimulation.<br>The second section is devoted to the in vivo study of antioxidants compounds for the prevention of the effects of oxidative stress, one of the main factors impacting on astronauts’ health (even after the space travel), even leading to damages to the nervous system. The model organisms used are zebrafish and planarian. Specifically, the effects of the nanobiotechnological antioxidant nanoceria (NC) on genes LMNA and H2afx was studied on zebrafish. A broad toxicology study was instead performed on planarians, not only using nanoceria but also other nanoantioxidants synthesized by our research group. Lipidic nanoparticles with tannic acid (L-TAFe NPs) were proven to be the most effective in preventing planarians’ death after the chemical induction of oxidative stress, therefore they were used in the subsequent microgravity studies. For this purpose, treated and untreated planarians were placed on the random positioning machine (RPM), which simulates microgravity. Both the effects of microgravity and the effect of L-TAFe NPs will be evaluated through transcriptomics and proteomics studies.<br>Two additional lines of research were identified while performing the abovementioned experiments and the care of the colony: the first one investigates the effect of hypoxia on planarians regeneration, the second one focused on the study and characterisation of a population of planarians we defined as “giants”. The first investigation direction comes from the need to understand the effect of hypoxia on planarians regeneration after the observation, in our colony, of a Janus-tailed specimen. This phenotype is not present in nature, and it is usually obtained through molecular biology techniques. We hypothesize that in our case hypoxia alone interferes with the WNT/ß catenin, which is crucial in determining the antero-posterior axis.<br>The second line of research was instead defined after the observation of a sub-population of planarians with increased size compared to the wild type. Our current explanation of the phenomenon is the use of a specific salt present in the medium where they live, and additional experiments were performed to evaluate if the augmented size was also accompanied by gonads formation in the GI strain, usually devoid of them.<br>