Lorena Anna Ditta

Ionizing radiation-engineered nanogels as insulin nanocarriers for the development of a new strategy for the treatment of Alzheimer's disease

A growing body of evidence shows the protective role of insulin in Alzheimers disease (AD). A nanogel system (NG) to deliver insulin to the brain, as a tool for the development of a new therapy for Alzheimers Disease (AD), is designed and synthetized. A carboxyl-functionalized poly(N-vinyl pyrrolidone) nanogel system produced by ionizing radiation is chosen as substrate for the covalent attachment of insulin or fluorescent molecules relevant for its characterization. Biocompatibility and hemocompatibility of the naked carrier is demonstrated. The insulin conjugated to the NG (NG-In) is protected by protease degradation and able to bind to insulin receptor (IR), as demonstrated by immunofluorescence measurements showing colocalization of NG-In(FITC) with IR. Moreover, after binding to the receptor, NG-In is able to trigger insulin signaling via AKT activation. Neuroprotection of NG-In against dysfunction induced by amyloid β (Aβ), a peptide mainly involved in AD, is verified. Finally, the potential of NG-In to be efficiently transported across the Blood Brain Barrier (BBB) is demonstrated. All together these results indicate that the synthesized NG-In is a suitable vehicle system for insulin deliver in biomedicine and a very promising tool to develop new therapies for neurodegenerative diseases.

Nose-to-brain delivery of insulin enhanced by a nanogel carrier.

Abstract Recent evidences suggest that insulin delivery to the brain can be an important pharmacological therapy for some neurodegenerative pathologies, including Alzheimer disease (AD). Due to the presence of the Blood Brain Barrier, a suitable carrier and an appropriate route of administration are required to increase the efficacy and safety of the treatment. Here, poly(N‐vinyl pyrrolidone)‐based nanogels (NG), synthetized by e‐beam irradiation, alone and with covalently attached insulin (NG‐In) were characterized for biocompatibility and brain delivery features in a mouse model. Preliminarily, the biodistribution of the “empty” nanocarrier after intraperitoneal (i.p.) injection was investigated by using a fluorescent‐labeled NG. By fluorescence spectroscopy, SEM and dynamic light scattering analyses we established that urine clearance occurs in 24 h. Histological liver and kidneys inspections indicated that no morphological alterations of tissues occurred and no immunological response was activated after NG injection. Furthermore, after administration of the insulin‐conjugated nanogels (NG‐In) through the intranasal route (i.n.) no alteration or immunogenic response of the nasal mucosa was observed, suggesting that the formulation is well tolerated in mouse. Moreover, an enhancement of NG‐In delivery to the different brain areas and of its biological activity, measured as Akt activation levels, with reference to free insulin administration was demonstrated. Taken together, these results indicate that the synthesized NG‐In enhances brain insulin delivery upon i.n. administration and strongly encourage its further evaluation as therapeutic agent against some neurodegenerative diseases. Graphical abstract Figure. No Caption available.

Nanogel-antimiR-31 conjugates affect colon cancer cells behaviour

Soft and flexible nanogels, produced by electron beam (e-beam) irradiation of poly(N-vinyl pyrrolidone) and acrylic acid, were evaluated as delivery devices of the inhibitor of miR-31, a small RNA molecule with an important role in colorectal cancer (CRC) progression. The nanogel carriers developed possess both carboxyl and primary amino groups; the former were activated to react with the primary amino group present in the purposely-functionalised AntimiR-31. Very high conjugation reaction yields were attained, as well as a remarkable colloidal and storage stability of the conjugates. The ability of these nanoconstructs to be internalized by cells and the specific interaction of conjugated AntimiR with its biological target, without being detached from the nanogel, was demonstrated in vitro. These results are a strong encouragement to further proceed in the pre-clinical evaluation of the therapeutic effects of these formulations in CRC.