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2.
Anal Chem ; 82(19): 8203-10, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20828205

RESUMO

This paper describes the label-free detection of carbohydrate-lectin interactions. The sensor consists of a boron-doped diamond (BDD) electrode terminated with alkynyl surface groups, which have been functionalized via the CuACC (copper(I)-catalyzed azide-alkyne cycloaddition) "click" reaction with carbohydrate analogues bearing an azido-terminating arm. In this work, electrochemical impedance spectroscopy (EIS) was used as an effective technique to probe the specific interactions of the surface-bound carbohydrates with their complementary lectin partners, and the response was found to be dependent on the relative density of sugar units immobilized on the BDD surface. A BDD interface with 60% surface-bound mannose showed a detection limit of ∼5 ± 0.5 nM for Lens culinaris lectin, with an affinity constant of K(A) = (2.63 ± 0.5) × 10(6) M(-1).


Assuntos
Boro/química , Diamante/química , Espectroscopia Dielétrica/métodos , Técnicas Eletroquímicas/métodos , Lectinas/análise , Manose/química , Catálise , Cobre/química , Eletrodos , Ferricianetos/química , Lens (Planta)/metabolismo , Propriedades de Superfície
3.
ACS Omega ; 5(14): 8137-8145, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32309723

RESUMO

This study highlights recent advances in the synthesis of nanoconjugates based on gold (Au(III)) complex with a bioactive polymer bearing sulfonate groups called thiol-poly(sodium styrene sulfonate) (PolyNaSS-SH) with various molecular weights (5, 10, and 35 kDa). The three nanomaterials differ substantially in shape and structure. In particular, for PolyNaSS-SH of 35 kDa, we obtained a characteristic core-shell flower shape after chelation of the Au(III) ions and successively reduction with sodium borohydride (NaBH4). The mechanism of formation of the hybrid nanoparticles (PolyNaSS-SH@AuNPs (35 kDa) and their interactions between plasmatic proteins (human serum albumin (HSA), collagen I (Col 1), and fibronectin (Fn)) were deeply studied from a chemical and physical point of view by using several analytical techniques such as Raman spectroscopy, UV-visible, transmission electron microscopy (TEM), 1H NMR, and X-ray photoelectron spectroscopy (XPS).

4.
Nanoscale ; 7(6): 2325-35, 2015 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-25559389

RESUMO

Recent advances in nanotechnology have seen the development of a number of microbiocidal and/or anti-adhesive nanoparticles displaying activity against biofilms. In this work, trimeric thiomannoside clusters conjugated to nanodiamond particles (ND) were targeted for investigation. NDs have attracted attention as a biocompatible nanomaterial and we were curious to see whether the high mannose glycotope density obtained upon grouping monosaccharide units in triads might lead to the corresponding ND-conjugates behaving as effective inhibitors of E. coli type 1 fimbriae-mediated adhesion as well as of biofilm formation. The required trimeric thiosugar clusters were obtained through a convenient thiol-ene "click" strategy and were subsequently conjugated to alkynyl-functionalized NDs using a Cu(I)-catalysed "click" reaction. We demonstrated that the tri-thiomannoside cluster-conjugated NDs (ND-Man3) show potent inhibition of type 1 fimbriae-mediated E. coli adhesion to yeast and T24 bladder cells as well as of biofilm formation. The biofilm disrupting effects demonstrated here have only rarely been reported in the past for analogues featuring such simple glycosidic motifs. Moreover, the finding that the tri-thiomannoside cluster (Man3N3) is itself a relatively efficient inhibitor, even when not conjugated to any ND edifice, suggests that alternative mono- or multivalent sugar-derived analogues might also be usefully explored for E. coli-mediated biofilm disrupting properties.


Assuntos
Biofilmes , Diamante/química , Escherichia coli/metabolismo , Fímbrias Bacterianas/metabolismo , Manosídeos/química , Nanopartículas/química , Aderência Bacteriana , Materiais Biocompatíveis/química , Carboidratos/química , Linhagem Celular Tumoral , Cromatografia em Camada Fina , Dimerização , Glicosídeos/química , Proteínas de Fluorescência Verde/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Nanoconjugados , Nanotecnologia , Tamanho da Partícula , Espectroscopia Fotoeletrônica , Solventes/química
5.
Nanoscale ; 5(6): 2307-16, 2013 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-23396565

RESUMO

Bacterial attachment and subsequent biofilm formation on biotic surfaces or medical devices is an increasing source of infections in clinical settings. A large proportion of these biofilm-related infections are caused by Escherichia coli, a major nosocomial pathogen, in which the major adhesion factor is the FimH adhesin located at the tip of type 1 fimbriae. Inhibition of FimH-mediated adhesion has been identified as an efficient antibiotic-alternative strategy to potentially reduce E. coli-related infections. In this article we demonstrate that nanodiamond particles, covently modified with mannose moieties by a "click" chemistry approach, are able to efficiently inhibit E. coli type 1 fimbriae-mediated adhesion to eukaryotic cells with relative inhibitory potency (RIP) of as high as 9259 (bladder cell adhesion assay), which is unprecedented when compared with RIP values previously reported for alternate multivalent mannose-functionalized nanostructures designed to inhibit E. coli adhesion. Also remarkable is that these novel mannose-modified NDs reduce E. coli biofilm formation, a property previously not observed for multivalent glyco-nanoparticles and rarely demonstrated for other multivalent or monovalent mannose glycans. This work sets the stage for the further evaluation of these novel NDs as an anti-adhesive therapeutic strategy against E. coli-derived infections.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Diamante , Escherichia coli/fisiologia , Fímbrias Bacterianas/metabolismo , Glucanos , Nanopartículas/química , Adesinas de Escherichia coli/metabolismo , Diamante/química , Diamante/farmacologia , Proteínas de Fímbrias/metabolismo , Glucanos/química , Glucanos/farmacologia
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