Search results for "nanogel"

Neuroprotective effect of a new Insulin-Nanogel system

2015

Nanogels (NGs) have a great potential in the development of “smart” nanocarriers for (bio)molecular drugs and contrast agent for bioimaging. They are formed by physically or chemically crosslinked polymer networks, characterized by a large and flexible surface available for multivalent bioconjugations. NGs can be produced with high yields and through-puts by pulsed electron-beam irradiation of dilute aqueous solutions of water-soluble biocompatible polymers. In this work, a carboxyl functionalized nanogel system (NG), generated by pulsed e-beam irradiation of a semi-dilute poly(N-vinyl pyrrolidone) (PVP) aqueous solution in the presence of acrylic acid, with an average diameter in the 60-70…

Macromolecular design and preparation of nanogels as pharmaceutical carriers

2010

Radiation-induced synthesis of nanogels: advances in research and applications

2016

From their first appearance in 1969, when Schnagel and Borwardt reported the radiochemical synthesis of poly(ethylene oxide) microgels by gamma-irradiation, the possibility of generating crosslinked micro- and nanoparticles from ”pure” aqueous solutions of macromolecules, have triggered the imagination of material scientists on the search for ”clean” processes and products for biomedical applications. Thanks to the seminal studies of Rosiak and co-workers, who have clarified, both experimentally and mechanistically, the key role of intra-molecular crosslinking in controlling the particle size, the scientific community has now a powerful tool to design and manufacture radiation-synthetized n…

Large-scale Radiation Manufacturing of Hierarchically Assembled Nanogels

2012

Nanogels (NGs), or small particles formed by physically or chemically crosslinked polymer networks, represent a niche in the development of “smart” nanoparticles for drug delivery and diagnostics. They offer unique advantages over other systems, including a large and flexible surface for multivalent bio-conjugation; an internal 3D aqueous environment for incorporation and protection of (bio)molecular drugs; the possibility to entrap active metal or mineral cores for imaging or phototherapeutic purposes; stimuli-responsiveness to achieve temporal and/or site control of the release function and biocompatibility. The availability of inexpensive and robust preparation methodologies is at the ba…

Sintesi di nanogeli per la veicolazione di insulina al cervello: una strategia per il trattamento della malattia di Alzheimer

2016

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 c…

Nanohydrogel Formation within the Halloysite Lumen for Triggered and Sustained Release

2018

An easy strategy to obtain nanohydrogels within the halloysite nanotube (HNTs) lumen was investigated. Inorganic reverse micelles based on HNTs and hexadecyltrimethylammonium bromides were dispersed in chloroform, and the hydrophilic cavity was used as a nanoreactor to confine the gel formation based on alginate cross-linked by calcium ions. Spectroscopy and electron microscopy experiments proved the confinement of the polymer into the HNT lumen and the formation of calcium-mediated networks. Biological tests proved the biocompatibility of the hybrid hydrogel. The nanogel in HNTs was suitable for drug loading and sustained release with the opportunity of triggered burst release by chemical …

Numerical simulations of the kinetics of pulsed electron beam induced synthesis of nanogels in dilute aqueous polymer solutions

2018

Nanogel can be produced by irradiation of dilute aqueous polymer solutions. The nanogels are formed primarily through intramolecular radical-radical crosslinking reactions between two polymer radical sites.

On the nature of macroradicals formed upon radiolysis of aqueous poly(N-vinylpyrrolidone) solutions

2020

In this work we have explored the nature of macroradicals formed upon radiolysis of aqueous poly(N-vinylpyrrolidone) (PVP) solutions using pulse radiolysis, density functional theory (DFT) and literature data. On the basis of literature data on site-specific kinetics of hydrogen abstraction from simple amides and spectra corresponding to specific radical sites on the same amides we have assessed the distribution of H-atom abstraction by `OH radicals from different positions on the pyrrolidone ring and the polymer backbone. Pulse radiolysis experiments performed at different doses per pulse and different PVP concentrations demonstrate that the H-abstracting radiolysis products are not quanti…

Oligonucleotide-decorated carboxyl-modified PVP nanogels: a new platform for diagnosis and gene-therapy.

2012

Nanogels, or nanoscalar chemically crosslinked polymer networks, were generated by simultaneous crosslinking of Poly(N-vinyl pyrrolidone) (PVP) and grafting of acrylic acid (AA) monomer through e-beam irradiation of their aqueous solutions. The yield of the process is very high and no separation or complex purification procedures are required since no recourse to surfactants or organic solvents is made. The administered irradiation dose (40 kGy) imparts also sterility to the obtained nanogels in the form of aqueous dispersions. Control of particle size and size-distribution can be achieved by proper selection of the irradiation conditions. In particular, we obtained nanogel variants with av…

Multi-Functional Nanogels for Tumor Targeting and Redox-Sensitive Drug and siRNA Delivery

2016

(1) Background: A new family of nanosystems able to discern between normal and tumor cells and to release a therapeutic agent in controlled way were synthetized by e-beam irradiation. This technique permits to obtain biocompatible, sterile, carboxyl-functionalized polyvinylpyrrolidone (PVP-co-acrylic acid) nanogels (NGs); (2) Methods: Here, we performed a targeting strategy based on the recognition of over-expressed proteins on tumor cells, like the folate receptor. The selective targeting was demonstrated by co-culture studies and flow cytometry analysis, using folate conjugated NGs. Moreover, nanoparticles were conjugated to a chemotherapeutic drug or to a pro-apoptotic siRNA through a gl…