Search results for "Diamines"
showing 10 items of 43 documents
Amphiphilic Copolymers Based on Poly[(hydroxyethyl)-d,l-aspartamide]: A Suitable Functional Coating for Biocompatible Gold Nanostars
2013
Novel amphiphilic copolymers have been synthesized based on a biocompatible poly(hydroxyethylaspartamide) (PHEA) backbone, bearing both anchoring groups for gold nanoparticles, such as thiols and disulfide, and conjugable moieties, such as amino groups, the latter as points suitable for appending further functional agents. The strategy was to functionalize α,β-poly[(N-2- hydroxyethyl)-d,l-aspartamide] (PHEA) with PEG2000-NH2 and with ethylenediamine (EDA) obtaining a partially pegylated copolymer with a large number of pendant primary amino groups. A fraction of the latter was conjugated with molecules bearing terminal thiol moieties such as 12-mercaptododecanoic acid (MDA) and disulfide gr…
Size- and coating-dependent uptake of polymer-coated gold nanoparticles in primary human dermal microvascular endothelial cells.
2012
A library-orientated approach is used to gain understanding of the interactions of well-defined nanoparticles with primary human endothelial cells, which are a key component of the vasculature. Fifteen sequentially modified gold nanoparticles (AuNPs) based on three different core sizes (18, 35, 65 nm) and five polymeric coatings were prepared. The synthetic methodology ensured homogeneity across each series of particles to allow sequential investigation of the chemical features on cellular interactions. The toxicity of these nanoparticles, their uptake behavior in primary human dermal microvascular endothelial cells (HDMECs), and quantification of uptake were all investigated. The results o…
New hyaluronic acid based brush copolymers synthesized by atom transfer radical polymerization.
2013
Abstract In this work, an efficient method for the synthesis of hyaluronic acid based brush copolymers using atom transfer radical polymerization (ATRP) has been reported. At first, two different hyaluronic acid (HA) based macroinitiators have been prepared and then they have been used for the polymerization via ATRP of hydrophilic or hydrophobic molecules carrying vinyl portions. In particular, by linking 2-bromo-2-methylpropionic acid (BMP) to the primary hydroxyl groups of tetrabutyl ammonium salt of HA (HA–TBA) or to amino groups of the ethylenediamino derivative of HA–TBA (HA–TBA–EDA), two macroinitiators (HA–TBA–BMP and HA–TBA–EDA–BMP) have been obtained. Then they have been used for …
A POLYCARBOXYLIC/AMINO FUNCTIONALIZED HYALURONIC ACID DERIVATIVE FOR THE PRODUCTION OF pH SENSIBLE HYDROGELS IN THE PREVENTION OF BACTERIAL ADHESION …
2014
A graft copolymer derivative of hyaluronic acid bearing pendant amino and short polymethacrylate portions (HA-EDA-BMP-MANa) has been employed for the production of a pH sensible vancomycin releasing hydrogel and studied in vitro to test its potential anti adhesive property against Staphylococcus aureus colonization. The copolymer obtained through atom transfer radical polymerization bears chargeable (carboxyl and amino groups) portions and it could be formulated as a hydrogel at a concentration of 10% w/v. The HA-EDA-BMP-MANa hydrogels, produced at three different pH values (5, 6 and 7, respectively), were formulated with or without the addition of vancomycin (2% w/v). The vancomycin releas…
DNA interaction of CuII, NiII and ZnII functionalized salphen complexes: studies by linear dichroism, gel electrophoresis and PCR.
2013
The interaction of salphen-type NiII, CuII and ZnII complexes with native DNA was investigated by exploiting linear dichroism experiments. The NiII complex behaves as a typical intercalator, binding strongly and stiffening and unwinding the DNA. The strength of the DNA interaction is slightly weaker for the copper complex and much weaker for the zinc complex. Plasmid-DNA gel electrophoresis experiments indicated that while CuII and ZnII complexes do not induce the unwinding of supercoiled DNA, the NiII complex has a nuclease activity without the addition of external agents. On the other hand, as shown in the PCR assays, we demonstrate that, at the used concentrations, only the CuII complex …
Polymeric drug delivery micelle-like nanocarriers for pulmonary administration of beclomethasone dipropionate
2017
In this paper, the potential of novel polymeric micelles as drug delivery systems for Beclomethasone Dipropionate (BDP) administration into the lung is investigated. These nanostructures are obtained starting from α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA), which was subsequently functionalized with O-(2-aminoethyl)-Oâ-methylpolyethylenglycole (PEG2000), ethylenediamine (EDA) and lipoic acid (LA), obtaining PHEA-PEG2000-EDA-LA graft copolymer. Empty and drug-loaded micelles possess adequate chemical-physical characteristics for pulmonary administration such as spherical shape, slightly positive surface charge and mean size of about 200 nm. Besides, BDP-loaded micelles, obtained …
Palladium(II)-Mediated Addition of Benzenediamines to Isocyanides: Generation of Three Types of Diaminocarbene Ligands Depending on the Isomeric Stru…
2016
Coupling of the palladium-bis(isocyanide) complexes cis-[PdCl2(CNR)2] (R = 2,6-Me2C6H3 1, 2-Cl-6-MeC6H3 2) with benzene-1,3-diamine (BDA1) leads to the diaminocarbene species cis-[PdCl2(CNR){C(NHR)═NH(1,3-C6H4NH2)}] (5 and 6, respectively). In this reaction, BDA1 behaves as a monofunctional nucleophile that adds to one of the RNC ligands by one amino group. By contrast, the reaction of 1 and 2 with benzene-1,4-diamine (BDA2) involves both amino functionalities of the diamine and leads to the binuclear species [cis-PdCl2(CNR){μ-C(NHR)═NH(1,4-C6H4)NH═C(NHR)}-(cis)-PdCl2(CNR)] (6 and 7) featuring two 1,4-bifunctional diaminocarbene ligands. The reaction of cis-[PdCl2(CNR)2] (R = cyclohexyl 3) …
Diastereoselective Synthesis of Enantioenriched Trifluoromethylated Ethylenediamines and Isoindolines Containing Two Stereogenic Carbon Centers by Nu…
2020
Fluoroform, HFC-23, is an industrial byproduct from the synthesis of polytetrafluoroethylene and is a vastly underused resource; however, its physicochemical properties have hindered progress toward synthetic uses. Herein, we describe the use of HFC-23 as a cheap trifluoromethylating agent in two reactions for the highly diastereoselective synthesis of medicinally attractive chiral amines with two stereogenic carbon centers: a base-dependent, stereodivergent nucleophilic addition to synthesize enantioenriched vicinal diamines and a tandem nucleophilic addition/aza-Michael sequence toward enantioenriched isoindolines.
The spectrum of allergic (cross-)sensitivity in clinical patch testing with 'para amino' compounds
2002
Background: Allergic contact sensitization to ‘para amino’ compounds is frequent and the spectrum of cross-reactivity between members of this chemical group is variable. Methods: A retrospective analysis of clinical patch test data obtained with a special test series in the centres of the Information Network of Departments of Dermatology (IVDK) between 1995 and 1999. Results: In the 638 patients tested with the above test panel positive reactions were observed most often to p-aminoazobenzene (16.2%), p-phenylenediamine (14.1%), p-toluylenediamine (10.0%), followed by 4,4′-diaminodiphenylmethane (8.5%), Disperse Orange 3 (8.4%) and p-aminophenol (3.1%). Among the 544 patients tested with p-p…