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1.
Nature ; 630(8016): 447-456, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38839969

RÉSUMÉ

Increasing rates of autoimmune and inflammatory disease present a burgeoning threat to human health1. This is compounded by the limited efficacy of available treatments1 and high failure rates during drug development2, highlighting an urgent need to better understand disease mechanisms. Here we show how functional genomics could address this challenge. By investigating an intergenic haplotype on chr21q22-which has been independently linked to inflammatory bowel disease, ankylosing spondylitis, primary sclerosing cholangitis and Takayasu's arteritis3-6-we identify that the causal gene, ETS2, is a central regulator of human inflammatory macrophages and delineate the shared disease mechanism that amplifies ETS2 expression. Genes regulated by ETS2 were prominently expressed in diseased tissues and more enriched for inflammatory bowel disease GWAS hits than most previously described pathways. Overexpressing ETS2 in resting macrophages reproduced the inflammatory state observed in chr21q22-associated diseases, with upregulation of multiple drug targets, including TNF and IL-23. Using a database of cellular signatures7, we identified drugs that might modulate this pathway and validated the potent anti-inflammatory activity of one class of small molecules in vitro and ex vivo. Together, this illustrates the power of functional genomics, applied directly in primary human cells, to identify immune-mediated disease mechanisms and potential therapeutic opportunities.


Sujet(s)
Inflammation , Macrophages , Protéine proto-oncogène c-ets-2 , Femelle , Humains , Mâle , Anti-inflammatoires/pharmacologie , Anti-inflammatoires/usage thérapeutique , Cellules cultivées , Chromosomes humains de la paire 21/génétique , Bases de données factuelles , Régulation de l'expression des gènes , Étude d'association pangénomique , Génomique , Haplotypes/génétique , Inflammation/génétique , Maladies inflammatoires intestinales/génétique , Macrophages/immunologie , Macrophages/métabolisme , Macrophages/anatomopathologie , Protéine proto-oncogène c-ets-2/génétique , Protéine proto-oncogène c-ets-2/métabolisme , Reproductibilité des résultats , Facteurs de nécrose tumorale/métabolisme , Interleukine-23/métabolisme
2.
Mater Sci Eng C Mater Biol Appl ; 55: 547-55, 2015 Oct.
Article de Anglais | MEDLINE | ID: mdl-26117788

RÉSUMÉ

Nowadays, with the increase of elderly population and related health problems, knee and hip joint prosthesis are being widely used worldwide. However, failure of these invasive devices occurs in a high percentage thus demanding the revision of the chirurgical procedure. Within the reasons of failure, microbial infections, either hospital or subsequently-acquired, contribute in high number to the statistics. Staphylococcus epidermidis (S. epidermidis) has emerged as one of the major nosocomial pathogens associated with these infections. Silver has a historic performance in medicine due to its potent antimicrobial activity, with a broad-spectrum on the activity of different types of microorganisms. Consequently, the main goal of this work was to produce Ag-ZrCN coatings with antimicrobial activity, for the surface modification of hip prostheses. Thin films of ZrCN with several silver concentrations were deposited onto stainless steel 316 L, by DC reactive magnetron sputtering, using two targets, Zr and Zr with silver pellets (Zr+Ag target), in an atmosphere containing Ar, C2H2 and N2. The antimicrobial activity of the modified surfaces was tested against S. epidermidis and the influence of an activation step of silver was assessed by testing samples after immersion in a 5% (w/v) NaClO solution for 5 min. The activation procedure revealed to be essential for the antimicrobial activity, as observed by the presence of an inhibition halo on the surface with 11 at.% of Ag. The morphology analysis of the surface before and after the activation procedure revealed differences in silver distribution indicating segregation/diffusion of the metallic element to the film's surface. Thus, the results indicate that the silver activation step is responsible for an antimicrobial effect of the coatings, due to silver oxidation and silver ion release.


Sujet(s)
Anti-infectieux/pharmacologie , Matériaux revêtus, biocompatibles , Cyanures/composition chimique , Argent/composition chimique , Zirconium/composition chimique , Anti-infectieux/composition chimique , Microscopie électronique à balayage , Spectroscopie photoélectronique
3.
Mater Sci Eng C Mater Biol Appl ; 34: 22-8, 2014 Jan 01.
Article de Anglais | MEDLINE | ID: mdl-24268229

RÉSUMÉ

With the increase of elderly population and the health problems arising nowadays, such as cancer, knee and hip joint prostheses are widely used worldwide. It is estimated that 20% of hip replacement surgeries simply fail after 5years, due to wear loosening, instability and infection. In this paper it is reported the study of advanced materials with the ability to overcome some of these drawbacks. The development of ceramic coatings, based on carbonitrides of transition metals, such as TiCN, doped with silver, Ag, may represent an effective solution. Thin films of Ag-TiCN were produced by dc reactive magnetron sputtering with silver contents ranging from 4 to 8at.%. The physical, chemical, structural, morphological/topographical, mechanical and tribological properties were evaluated. The tribological tests were performed in a unidirectional wear simulator, pin on disk, being the antagonists of a ceramic Al2O3 ball, and using simulate body fluids as lubricant. Hank's Balanced Salt Solution (HBSS) and bovine serum albumin (BSA) in HBSS were chosen, in order to evaluate the lubrication ability of the solution containing the protein, albumin. The results revealed that the coatings with Ag content ranging from 4 to 8at.%, were the most promising, as the tribological properties were superior to the results reported by other authors, which also developed Ag-TiCN coatings containing similar Ag contents and using similar test conditions. The presence of albumin leads to a lower wear in all the test conditions, and this enhancement was higher in the hydrophobic surfaces.


Sujet(s)
Test de matériaux , Orthopédie , Prothèses et implants , Sérumalbumine bovine/pharmacologie , Argent/pharmacologie , Titane/pharmacologie , Animaux , Bovins , Matériaux revêtus, biocompatibles/pharmacologie , Module d'élasticité/effets des médicaments et des substances chimiques , Lubrification , Microscopie à force atomique , Spectroscopie photoélectronique , Analyse spectrale Raman , Tension superficielle/effets des médicaments et des substances chimiques , Diffraction des rayons X
4.
Int J Pharm ; 456(2): 269-81, 2013 Nov 18.
Article de Anglais | MEDLINE | ID: mdl-24008084

RÉSUMÉ

A supercritical carbon dioxide (scCO2)-assisted foaming/mixing method (SFM) was implemented for preparing dexamethasone (DXMT)-loaded poly(ε-caprolactone)/silica nanoparticles (PCL/SNPs) composite materials suitable for bone regeneration. The composites were prepared from PCL and mesoporous SNPs (MCM-41/SBA-15) by means of scCO2-assisted SFM at several operational pressures, processing times and depressurization conditions. DXMT was loaded into SNPs (applying a scCO2 solvent impregnation/deposition method - SSID) and into PCL/SNPs composites (using the SFM method). The effects of the employed operational and compositional variables on the physicochemical and morphological features as well as in the in vitro release profiles of DXMT were analyzed in detail. This work demonstrates that the above-referred scCO2-based methods can be very useful for the preparation of DXMT-loaded PCL/SNPs composites with tunable physicochemical, thermomechanical, morphological and drug release properties and suitable for hard-tissue regeneration applications.


Sujet(s)
Dioxyde de carbone/composition chimique , Chromatographie en phase supercritique/méthodes , Dexaméthasone/synthèse chimique , Nanoparticules/composition chimique , Polyesters/synthèse chimique , Silice/synthèse chimique , Diffraction des rayons X
5.
J Nanosci Nanotechnol ; 9(6): 3792-7, 2009 Jun.
Article de Anglais | MEDLINE | ID: mdl-19504921

RÉSUMÉ

Functionally graded nanocomposite thin films (2D-FGM), of sub-micrometric thickness, were co-deposited from austenitic stainless steel (316L (AISI)) and poly(tetrafluoroethylene) targets by r.f. magnetron sputtering. All the deposition parameters were kept constant except for the electrical characteristics applied to polymeric target. XPS revealed in the films fluorine contents between 0 and 60 at%. The TEM analysis revealed the evolution towards a nanocomposite structure with an increase in fluorine content (from 0 to 20 at%). For the higher fluorine contents the formation of a ceramic phase, FeF2, is the main structural feature. The hardness is higher for the films with the lowest fluorine concentration due to higher chromium carbides content. The residual stresses of the 2D-FGM are essentially compressive with values up to 2.2 GPa. The values of the friction coefficient of the nanocomposite thin films are in the range of 0.66-0.71, an exception is for the highest fluorine content where the value is 0.31.

6.
Acta Biomater ; 4(4): 1073-80, 2008 Jul.
Article de Anglais | MEDLINE | ID: mdl-18406221

RÉSUMÉ

Thin films of stainless steel and poly(tetrafluoroethylene) were co-deposited, by radiofrequency magnetron sputtering, in an inert atmosphere in order to produce a functionally graded material as a coating on a traditional biomaterial, where non-ferromagnetic characteristics and improved wettability must be ensured. These thin films are intended to modify the surface of SS316L used in stents, where the bulk/thin film couple should be regarded as a single material. This requires excellent adhesion of the coating to the substrate. All coatings were deposited with an average thickness of 500 nm. The chemical and phase characterization of the surface revealed that, with the increase in F content, the thin film evolves from a ferritic phase (alpha) to an amorphous phase with dispersion of a new crystalline ceramic phase (FeF(2)). For intermediate F content values, an austenitic (111) phase (gamma) was present. Bearing in mind the envisaged application, the best results were attained for thin films with a fluorine content between 10 and 20 at.%.


Sujet(s)
Fluor/composition chimique , Polymères/composition chimique , Acier inoxydable/composition chimique , Adhésivité , Microanalyse par sonde électronique , Microscopie électronique à balayage , Analyse spectrale , Endoprothèses , Propriétés de surface , Eau/composition chimique
7.
Biosens Bioelectron ; 7(9): 645-52, 1992.
Article de Anglais | MEDLINE | ID: mdl-1292521

RÉSUMÉ

As part of the development of disposable urea bioselective probes, the covalent binding of urease on ammonium-selective potentiometric membranes has been assessed. Nonactin/bis(1-butylpentyl)adipate/poly(vinylchloride) (PVC) membranes, directly applied to an internal solid contact (conductive epoxy-graphite composite), has been used as a support for covalent immobilization of urease. Two types of all-solid-state construction process have been assayed: thin layers of cellulose acetate (CA) were coated on the PVC ammonium-selective membranes (type 1) and blends of PVC and CA at various ratios were used as ammonium-selective membrane matrices (type 2). Urease was covalently attached to CA via aldehyde groups. These groups were created on the polysaccharide with sodium periodate to which the enzyme was immobilized through a spacer (hexamethylenediamine). The viability of both types of probe for the determination of ammonium ions was assessed after each step of the activation process. Results indicated that type 2 potentiometric probes are altered after the treatment with sodium periodate. Good results were obtained with type 1 probes. Their dynamic concentration range of response to urea was from 2 x 10(-5) to 0.01 M with a sensibility of 50 mV/decade.


Sujet(s)
Ammoniac , Techniques de biocapteur , Membrane artificielle , Poly(chlorure de vinyle) , Urée/métabolisme , Urease/métabolisme , Cellulose/analogues et dérivés , Enzymes immobilisées , Structure moléculaire , Potentiométrie , Sensibilité et spécificité
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