Search results for " polymerization"

Sensory neuropathy in progressive motor neuronopathy(pmn)mice is associated with defects in microtubule polymerization and axonal transport

2016

Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) are now recognized as multi-system disorders also involving various non-motor neuronal cell types. The precise extent and mechanistic basis of non-motor neuron damage in human ALS and ALS animal models remain however unclear. To address this, we here studied progressive motor neuronopathy (pmn) mice carrying a missense loss-of-function mutation in tubulin binding cofactor E (TBCE). These mice manifest a particularly aggressive form of motor axon dying back and display a microtubule loss, similar to that induced by human ALS-linked TUBA4A mutations. Using whole nerve confocal imaging of pmn × thy1.2-YFP16 fluorescent reporter …

Hippocampal hyperexcitability is modulated by microtubule-active agent: evidence from in vivo and in vitro epilepsy models in the rat

2016

The involvement of microtubule dynamics on bioelectric activity of neurons and neurotransmission represents a fascinating target of research in the context of neural excitability. It has been reported that alteration of microtubule cytoskeleton can lead to profound modifications of neural functioning, with a putative impact on hyperexcitability phenomena. Altogether, in the present study we pointed at exploring the outcomes of modulating the degree of microtubule polymerization in two electrophysiological epileptiform activity in the rat hippocampus. To this aim, we used in vivo Maximal Dentate Activation (MDA) and in vitro hippocampal epileptiform bursting activity (HEBA) paradigms to asse…

The Importance of Developing Electrochemical Sensors Based on Molecularly Imprinted Polymers for a Rapid Detection of Antioxidants

2021

International audience; This review aims to pin out the importance of developing a technique for rapid detection of antioxidants, based on molecular imprinting techniques. It covers three major areas that have made great progress over the years in the field of research, namely: antioxidants characterization, molecular imprinting and electrochemistry, alone or combined. It also reveals the importance of bringing these three areas together for a good evaluation of antioxidants in a simple or complex medium, based on selectivity and specificity. Although numerous studies have associated antioxidants with molecular imprinting, or antioxidants with electrochemistry, but even electrochemistry wit…

Atomistic Simulations of Functional Gold Nanoparticles Au144(Sr)60 Interacting with Membranes

2013

Gold nanoparticles (AuNps) are used in nanomedicine in, e.g., drug delivery and bio-imaging. However, it is regrettable that the understanding of nanoparticle properties in cellular surroundings is incompletely understood. Here, we have complemented our previous studies [1] by performing extensive atomistic molecular dynamics simulations of lipid membranes interacting with charged gold nanoparticles. We have elucidated the action of these nanoparticles on membranes characterized by lipid compositional asymmetry in the two leaflets, thereby unraveling the interactions of AuNPs with both the extracellular and the cytosolic sides of plasma membranes of eukaryotic cells. We have found that ther…

1D coordination polymer based on copper(II)-containing tetrameric 1,2,3-triazole ligand from click chemistry: Magnetic and catalytic properties

2019

Abstract A novel tetrameric tetra[O-((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)]-pentaerythritol (TBTP) has been synthesized using click chemistry strategy. TBTP was characterized and used as ligand to form new Cu(II) complexes, forming 1-D coordination polymers. Two square planar complexes were characterized by single-crystal X-ray diffraction, presenting formula [Cu(TBTP)][Cu(NO3)4] (1) and [Cu(TBTP)](NO3)2 (2). In both structures, a cationic 1-D coordination polymer (CP) has been formed. The CP contain a 1:1 Cu(II)/TBTP ratio with four neutral triazole groups coordinating the Cu(II) center, forming a Cu N bonds ranging 1.988(2)–2.001(2) A. The study of the magnetic properties of compounds 1…

Eight-Membered Rings With Two Heteroatoms 1,2

2022

The chapter titled “Eight-membered Rings with two Heteroatoms 1,2” deals with heterocine rings with two heteroatoms in a 1,2 relationship, namely 1,2-diazocine, 2H-1,2-oxazocine, 2H-1,2-thiazocine, 1,2-dioxocin, 1,2-oxathiocin and 1,2-dithiocin. This article covers the literature from 2007 to 2019 and reports the chemistry of uncondensed derivatives, heterocines fused to carbocycles and heterocycles, as well as bridged heterocines. As usual, in the case that a particular section is not mentioned, it means that no chemistry has been reported. In this article, the “Biosynthesis” paragraph was additionally introduced, since in the latest years the contribution of Nature to the synthesis of dih…

Nanoparticles of a polyaspartamide-based brush copolymer for modified release of sorafenib: In vitro and in vivo evaluation.

2017

Abstract In this paper, we describe the preparation of polymeric nanoparticles (NPs) loaded with sorafenib for the treatment of hepatocellular carcinoma (HCC). A synthetic brush copolymer, named PHEA-BIB-ButMA (PBB), was synthesized by Atom Trasnfer Radical Polymerization (ATRP) starting from the α-poly( N -2-hydroxyethyl)- d , l -aspartamide (PHEA) and poly butyl methacrylate (ButMA). Empty and sorafenib loaded PBB NPs were, then, produced by using a dialysis method and showed spherical morphology, colloidal size, negative ζ potential and the ability to allow a sustained sorafenib release in physiological environment. Sorafenib loaded PBB NPs were tested in vitro on HCC cells in order to e…

Site-specific DBCO modification of DEC205 antibody for polymer conjugation

2018

The design of multifunctional polymer-based vectors, forming pDNA vaccines, offers great potential in cancer immune therapy. The transfection of dendritic immune cells (DCs) with tumour antigen-encoding pDNA leads to an activation of the immune system to combat tumour cells. In this work, we investigated the chemical attachment of DEC205 antibodies (aDEC205) as DC-targeting structures to polyplexes of P(Lys)-b-P(HPMA). The conjugation of a synthetic block copolymer and a biomacromolecule with various functionalities (aDEC205) requires bioorthogonal techniques to avoid side reactions. Click chemistry and in particular the strain-promoted alkyne-azide cycloaddition (SPAAC) can provide the req…

Improved SiRNA Loading of Cationic Nanohydrogel Particles by Variation of Crosslinking Density

2019

Acid‐Cleavable Poly(ethylene glycol) Hydrogels Displaying Protein Release at pH 5

2020

Abstract PEG is the gold standard polymer for pharmaceutical applications, however it lacks degradability. Degradation under physiologically relevant pH as present in endolysosomes, cancerous and inflammatory tissues is crucial for many areas. The authors present anionic ring‐opening copolymerization of ethylene oxide with 3,4‐epoxy‐1‐butene (EPB) and subsequent modification to introduce acid‐degradable vinyl ether groups as well as methacrylate (MA) units, enabling radical cross‐linking. Copolymers with different molar ratios of EPB, molecular weights (M n) up to 10 000 g mol−1 and narrow dispersities (Đ<1.05) were prepared. Both the P(EG‐co‐isoEPB)MA copolymer and the hydrogels showed pH‐…