Search results for " NAnogels"

Micro- to Nanoscale Bio-Hybrid Hydrogels Engineered by Ionizing Radiation

2021

Bio-hybrid hydrogels consist of a water-swollen hydrophilic polymer network encapsulating or conjugating single biomolecules, or larger and more complex biological constructs like whole cells. By modulating at least one dimension of the hydrogel system at the micro- or nanoscale, the activity of the biological component can be extremely upgraded with clear advantages for the development of therapeutic or diagnostic micro- and nano-devices. Gamma or e-beam irradiation of polymers allow a good control of the chemistry at the micro-/nanoscale with minimal recourse to toxic reactants and solvents. Another potential advantage is to obtain simultaneous sterilization when the absorbed doses are wi…

Polymerization reactions and modifications of polymers by ionizing radiation

2020

International audience; Ionizing radiation has become the most effective way to modify natural and synthetic polymers through crosslinking, degradation, and graft polymerization. This review will include an in-depth analysis of radiation chemistry mechanisms and the kinetics of the radiation-induced C-centered free radical, anion, and cation polymerization, and grafting. It also presents sections on radiation modifications of synthetic and natural polymers. For decades, low linear energy transfer (LLET) ionizing radiation, such as gamma rays, X-rays, and up to 10 MeV electron beams, has been the primary tool to produce many products through polymerization reactions. Photons and electrons in…

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…

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.

Large-scale manufacturing of radiation sculptured therapeutic nanogels

2013

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. Yet, they offerunique 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 light-activemolecules, metal or mineral nanoparticles for imaging or phototherapeutic purposes; stimuli-responsiveness to achieve temporal and/or site control of the release function and biocompatibility. The availability of inexpensive, robust and versatile…

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…

Insulin Nanogels: a New Strategy for the Treatment of Alzheimer’s Disease

2016

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 c…

Numerical Simulation of the Kinetics of Radical Decay in Single-Pulse High-Energy Electron-Irradiated Polymer Aqueous Solutions

2019

A new method for the numerical simulation of the radiation chemistry of aqueous polymer solutions is introduced. The method makes use of a deterministic approach combining the conventional homogeneous radiation chemistry of water with the chemistry of polymer radicals and other macromolecular species. The method is applied on single-pulse irradiations of aqueous polymer solutions. The speciation of macromolecular species accounts for the variations in the number of alkyl radicals per chain, molecular weight, and number of internal loops (as a consequence of an intramolecular radical-radical combination). In the simulations, the initial polymer molecular weight, polymer concentration, and do…

Radiation-Engineered Multi-Functional Nanogels As Nanoscale Building Blocks Of Useful Biomedical Devices

2011

Radiation engineered nanogels as platforms for medical diagnostics and therapeutic nanodevices

2015

A scalable, single step, synthetic approach for the manufacture of biocompatible, functionalized microgels and nanogels has been developed. Pulsed EB irradiation of PVP aqueous solutions, at relatively low energies per pulse and doses within the sterilization dose range, has led to a variety of ‘as-born’ sterile, functional nanostructures that exhibit a combination of favourable properties which make them suitable as biomedical nanocarriers. Reactive functional groups have been generated by graft copolymerization of functional acrylic monomers. These groups can be used to attach fluorescent probes to the NPs, to bioconjugate ligands of specific cell receptors and to incorporate therapeutics…