Search

A growing body of evidence shows that Insulin, Insulin Receptor (IR) and IR signaling are involved in brain cognitive functions and their dysfunction is implicated in Alzheimer’s disease (AD) degeneration. Thus, administration of insulin could be a strategy for AD treatment. For this aim we have designed, synthesized and characterized a nanogel system (NG) to deliver insulin to the brain, as a tool for the development of a new therapy for AD. A carboxyl-functionalized poly(N-vinyl pyrrolidone) nanogel system produced by ionizing radiation was chosen as substrate for the covalent attachment of insulin or fluorescent molecules relevant for its characterization. Biocompatibility of the naked carrier was demonstrated by absence of cytotoxicity, oxidative stress and mitochondrial dysfunction. Hemocompatibility was demonstrated by hemolysis, coagulation time, leukocyte proliferation and inflammatory response tests. By immonufluorescence measurements we demonstrated that insulin conjugated to the NG (NG-In) is preotected by protease degradation and is able to bind and activate insulin receptor bringing to trigger the insulin signalling via AKT activation. Moreover, to provide consistent evidence on the functionality of the conjugated insulin on the glucose levels, the effect of NG-In was tested in mice demonstrating that plasma glucose levels was reduced. Neuroprotection of NG-In against dysfunction induced by amyloid β, a peptide mainly involved in AD, was verified. Finally, the potential of NG-In to be efficiently transported across the Blood Brain Barrier was demonstrated by using an in vitro system. All together these results indicated that the synthesized NG-In was a suitable vehicle system for insulin delivery in biomedicine and a very promising tool to develop new therapies for neurodegenerative diseases. The research eas supported by MIUR, FLAGSHIP PROJECT NanoMAX.

I nanogeli sono nanoparticelle polimeriche reticolate idrofile. La struttura polimerica del nanogelo permette la coniugazione di molecole che possano esplicare azioni terapeutiche, diagnostiche e di indirizzamento attivo su siti bersaglio. Le caratteristiche di flessibilità e conformabilità del nanogelo, e delle sue maglie, ne favoriscono l’attraversamento delle barriere biologiche, l’interazione di eventuali ligandi esposti sulla superfice con i recettori target, un’azione protettiva nei confronti del principio attivo incorporato. L’irraggiamento con radiazioni ionizzanti di soluzioni acquose di polimeri è una metodologia sintetica interamente “water-based”, che garantisce rese elevate e che può conferire sterilità al prodotto. [1] Lo studio presentato illustra la possibilità di produrre nanogeli a base di polivinilpirrolidone con le caratteristiche desiderate in termini di dimensioni e con gruppi funzionali disponibili per reazioni di coniugazione con l’insulina. L’obiettivo è quello di realizzare un nanovettore in grado di veicolare l’insulina al cervello attraverso la mucosa nasale. Studi recenti hanno dimostrato che l’insulina è in grado di ridurre la tossicità del peptide beta amiloide (A, coinvolto nella patogenesi della malattia di Alzheimer (MA), e di esplicare una funzione neuroprotettiva. [2, 3] Sono state studiate le caratteristiche dimensionali del nanosistema, la biocompatibilità e la funzione di protezione dalla tossicità indotta da Anei confronti di cellule di neuroblastoma.

Nanogels (NGs) are physically or chemically crosslinked polymer networks and are promising candidates in the development of therapeutic agent vectors. In fact, thanks to their tunable size and properties, they offer unique advantages, including a large and flexible surface for multivalent bio-conjugation, an internal 3D aqueous environment for incorporation and protection of (bio)molecular drugs, stimuliresponsiveness to achieve temporal and/or site control of the release function and biocompatibility. In order to develop effective NGs-based biomedical devices an inexpensive, robust and versatile synthetic methodology is required. In this perspective, we have produced NGs with high yields and through-puts by pulsed electron-beam irradiation. In particular, using an industrial electron accelerator, carboxyl functionalized NGs from a dilute aqueous solutions of poly(N-vinyl pyrrolidone) (PVP), and acrylic acid as functional monomer have been produced. This process allows simultaneous polymer cross-linking and monomer grafting. Moreover, depending on the value of the total irradiation dose, also the sterilization of the irradiated material can be obtained. Since organic solvents, toxic initiators or catalysts and surfactants are not required, this procedure can be defined as an eco-friendly and clean one. Crosslinked nanoparticles with multi-armed surfaces, and size, crosslinking density, and surface electric charge density controlled, have been generated. Nanogels produced have been proven to be hemocompatible and not cytotoxic or genotoxic at the cellular level. NGs have been decorated with fluorescent probes, proteins and anti-MiR. Thanks to the use of fluorescent variants, it has been argued that NGs showed a good affinity for cells, as they rapidly and quantitatively bypass the cellular compartments, accumulating in specific cell portions for the first hours, and being completely released from the cells in the next 24 hours. Moreover, it has been proven that the proteins and anti-MiR, once conjugated, maintain their biological activity giving rise to targeting features toward specific cell types.

A growing body of evidence shows that Insulin, Insulin Receptor (IR) and IR signaling are involved in brain cognitive functions and their dysfunction is implicated in neuronal degeneration associated with Alzheimer's disease (AD). Thus, the administration of insulin to the brain could be a strategy for the prevention and treatment of AD disease. With this aim, we have designed, synthesized and characterized a nanogel system (NG) that can be used as substrate for the conjugation of insulin and/or fluorescent molecules relevant for their characterization. In particular, a carboxyl-functionalized poly(N-vinyl pyrrolidone) nanogel system, has been produced by ionizing radiation starting from the polymeric aqueous solution and four insulin molecules per nanogel have been irreversibly attached. Absence of cytotoxicity, oxidative stress and mitochondrial dysfunction support the biocompatibility of the “naked” nanogels. Their hemocompatibility has been demonstrated by hemolysis, coagulation time, leukocyte proliferation and inflammatory response tests. By fluorescence measurements we have demonstrated that the insulin conjugated to the NG (NG-In) is protected by protease degradation and is able to bind and activate insulin receptor, thus triggering insulin signaling via AKT activation. In order to provide more significant evidence of the functionality of the insulin conjugated to the nanoparticles at the body level, the effect of NG-In in reducing the plasma glucose levels in mice has been demonstrated. Neuroprotection of NG-In against dysfunction induced by amyloid β, a peptide mainly involved in AD, has been also verified. Finally, the potential of NG-In to be efficiently transported across the Blood Brain Barrier has been demonstrated in vitro. All together, these results indicate that the synthesized NG-In is a suitable vehicle system for insulin deliver and a very promising tool to develop new therapies for neurodegenerative diseases

In recent years, polymer nanocomposites have fascinated scientists, engineers and industrialists on the premise that the creation of new and more performing polymeric materials is possible by the combination of different building blocks with controlled dimensions at the nanoscale. Unfortunately, uniform dispersion of the hetero-phase domains within the plastic matrix or on its surface often fails due to the unfavorable thermodynamics, thus resulting in migration and irreversible aggregation phenomena. In-situ generation of a dispersed hetero-phase within the same polymer matrix or in its precursors increases the chances of achieving a better control of morphology by eliminating the often critical harvesting and re-dispersion steps in the manufacturing process. Strong interaction at the interface must be also provided to avoid aggregation and coarse phase-separation in usage. With this purpose, radiation grafting of a functional monomer onto polypropylene film has been applied to modify the molecular structure and properties of the otherwise chemically inert film. The radiation-grafted film has become permeable to the precursors of polymerization of a conducting polymer, namely polyaniline that can grow as a thin skin from its surface as well as an interpenetrated network into the film. Chemical attachment of the conducting polymer to the polyolefin has been demonstrated. The nanocomposite film shows an increase of electrical conductivity of several orders of magnitudes and amenability to be used as flexible electrode. In consideration of the well-known possibility of controlling the extent and depth of chemical modification of a substrate by radiation grafting, by tuning both system composition and irradiation conditions, this approach can enable a good degree of control of the morphology of the heterophase that forms on or within the substrate and thereby of the nanocomposite film. The recourse to suitable carriers, as chaperones of active molecules or nanoparticles into structurally different polymer matrices, is another possible strategy to obtain more uniform and stable dispersions. For this purpose, the possibility of obtaining colloidally stable micro-/nanoparticles from a partially degalactosylated xyloglucan (Deg-XG) has been investigated. 60Co γ-irradiation was applied to reduce the size of polymeric clusters in water. Irradiation was performed on the solid powder in air, up to a maximum dose of 60 kGy. FTIR and GPC analyses do not evidence any significant change of functional groups of the polymer and its average molecular weight, respectively. Deconvolution of GPC curves point to a change in the proportion between two main fractions of different molecular weight clusters, with a prevailing contribution of the lower over the higher MW clusters at the increase of the absorbed dose. Aqueous dispersions of the irradiated materials at low concentrations were characterized by dynamic light scattering measurements as function of the time and at different temperatures. For all systems an increase of scattered light intensity as function of the time at 37°C was observed. The fastest kinetics and the highest pseudo-plateau were shown by the 20 kGy irradiated system. Globular particles with 300-400 nm hydrodynamic diameters are formed. Their propensity to incorporate hydrophobic small guest molecules or high molecular weight biomolecules was assessed. The possibility of preparing optically transparent films from native xyloglucan incorporating these particles by solvent casting was demonstrated.

recombinant allergens,natural allergens extracts, pollen hypersensitivity,component-resolved diagnosis

Hepatitis B surface antigen (HBsAg) is considered the best marker for the diagnosis of hepatitis B virus (HBV) infection. Mutations of the s gene involving amino acid substitutions within the a determinant could affect the sensitivity of diagnostic tests. In the present study, HBsAg mutants were detected in 3 immunocompromised patients, previously found to be HBsAg negative and anti-HBs positive. All patients had high levels of HBV-DNA, whereas HBsAg tests gave discordant results. Immunosuppression can cause viral reactivation of occult HBV infection in these patients and favour the selection of HBsAg a determinant mutants. 2010 S. Karger AG, Basel.

Introduction: The health-related quality of life in X-linked agammaglobulinemia was investigated in 25 children and adolescents patients through the Italian version of Pediatric Quality of Life Inventory 4.0 Generic Core Scale for patients aged less then 18 years, comparing child perception to that of the parents and the physician's evaluation. The data were compared with the ones of 80 healthy controls and the literature data of a group of patients with rheumatic diseases. Discussion: The agammaglobulinemia subjects perceived a lower global quality of life than the healthy subjects, but significantly higher than the rheumatic diseases controls. The clinical relevance of health-related quality of life assessment in X-linked agammaglobulinemia pediatric patients is discussed. © 2008 Springer Science+Business Media, LLC.

In this work Nylon 6,6 nanofibrous mats produced by electrospinning were used as interlayers in carbon fiber reinforced laminates. A high crossilinked epoxy resin was chosen as matrix. The effects of polymeric mats on cure behavior, thermal and delamination properties of the composite laminates were investigated.