Search results for "polymerization"

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…

Genetic, biological and structural hierarchies during sponge spicule formation: from soft sol–gels to solid 3D silica composite structures

2012

Structural biomaterials are hierarchically organized and biofabricated. Although the structural complexity of most bioskeletons can be traced back from the millimeter-scale to the micrometer- or submicrometer-scale, the biological and/or genetic basis controlling the synthesis of these skeletons and their building blocks remained unknown. There is one distinguished example, the spicules of the siliceous sponges, for which the principle molecules and molecular-biological processes involved in their formation have been elucidated in the last few years. In this review, recent data on the different levels of molecular, biological and structural hierarchies controlling the synthesis of the pictu…

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…

π-Stacked polymers in drug delivery applications

2016

Abstract Polybenzofulvenes are π-stacked polymers, which can be synthesized by spontaneous polymerization of the corresponding monomers without the use of catalysts or initiators. Therefore, they can be obtained completely free from byproducts, impurities, or harmful substances. The absence of any relevant toxic effects and cell viability impairments allows PEGylated polybenzofulvene brushes to be potentially functional in a wide range of biological, biomedical, and biotechnological applications. Moreover, the properties of these polymers, in terms of interaction with pharmacological active agents and the ability to self-assemble into nanoaggregates or a quite compact physical gel useful as…

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‐…