Recent advances in nanocarrier-loaded gels: Which drug delivery technologies against which diseases?

The combination of pharmaceutical technologies can be a wise choice for developing innovative therapeutic strategies. The association of nanocarriers and gels provides new therapeutic possibilities due to the combined properties of the two technologies. Gels support the nanocarriers, localize their administration to the target tissue, and sustain their release. In addition to the properties afforded by the gel, nanocarriers can provide additional drug sustained release or different pharmacokinetic and biodistribution profiles than those from nanocarriers administered by the conventional route to improve the drug therapeutic index. This review focuses on recent (over the last ten years) in vivo data showing the advances and advantages of using nanocarrier-loaded gels. Liposomes, micelles, liquid and solid lipid nanocapsules, polymeric nanoparticles, dendrimers, and fullerenes are all nanotechnologies which have been recently assessed for medical applications, such as cancer therapy, the treatment of cutaneous and infectious diseases, anesthesia, the administration of antidepressants, and the treatment of unexpected diseases, such as alopecia

Identification of a novel zinc metalloprotease through a global analysis of clostridium difficile extracellular proteins

Clostridium difficile is a major cause of infectious diarrhea worldwide. Although the cell surface proteins are recognized to be important in clostridial pathogenesis, biological functions of only a few are known. Also, apart from the toxins, proteins exported by C. difficile into the extracellular milieu have been poorly studied. In order to identify novel extracellular factors of C. difficile, we analyzed bacterial culture supernatants prepared from clinical isolates, 630 and R20291, using liquid chromatography-tandem mass spectrometry. The majority of the proteins identified were non-canonical extracellular proteins. These could be largely classified into proteins associated to the cell wall (including CWPs and extracellular hydrolases), transporters and flagellar proteins. Seven unknown hypothetical proteins were also identified. One of these proteins, CD630_28300, shared sequence similarity with the anthrax lethal factor, a known zinc metallopeptidase. We demonstrated that CD630_28300 (named Zmp1) binds zinc and is able to cleave fibronectin and fibrinogen in vitro in a zinc-dependent manner. Using site-directed mutagenesis, we identified residues important in zinc binding and enzymatic activity. Furthermore, we demonstrated that Zmp1 destabilizes the fibronectin network produced by human fibroblasts. Thus, by analyzing the exoproteome of C. difficile, we identified a novel extracellular metalloprotease that may be important in key steps of clostridial pathogenesis

Thichkness measurement of non–transparent free films by means of a double–side white–light interferometer

International audienceA double-side optical profilometer based on white-light interferometry was developed for thickness measurement of nontransparent films. The profile of the sample is measured simultaneously on both sides of the film. The resulting data allow the computation of the roughness, the flatness and the parallelism of the sides of the film, and the average thickness of the film. The key point is the apparatus calibration, i.e., the accurate determination of the distance between the reference mirrors of the complementary interferometers. Specific samples were processed for that calibration. The system is adaptable to various thickness scales as long as calibration can be made accurately. A thickness accuracy better than 30 nm for films thinner than 200 m is reported with the experimental material used. In this article, we present the principle of the method as well as the calibration methodology. Limitation and accuracy of the method are discussed. Experimental results are presented

Mechanical behavior study of laminate composite by three-color digital holography

Abstract A method for real time 3D measurements based on three-color digital holographic interferometry is presented and applied to the investigation of fracture mechanisms in laminate composite submitted to a three point flexural loading. A convolution algorithm allows the three monochrome images to be superposed to provide simultaneous full-field 3D measurements. Experimental results are presented and exploited to obtain the evolution of the crack tip propagation during the test

Performance of particleboards based on annual plant byproducts bound with bio-adhesives

International audienceBecause the timber market is more and more competitive, the particleboard manufacturers are looking for new sources of plant raw material. In the same time, the use of healthier, safer and more environmentally friendly materials becomes a priority in the building sector. In this context, using bio-based adhesives to bond the particles instead of the synthetic ones is an interesting alternative. In the same time agricultural byproducts as annual plant stems can be a sustainable alternative raw material. These resources are abundant, renewable and safe raw material. Moreover, their porous structure gives them interesting properties for building materials such as lightness and thermal insulation capacity. Two agricultural byproducts abundant in France have been studied: flax shives and sunflower bark. Particleboards were made at laboratory scale by thermocompression of the plant raw particles to a target density of 500 kg m−3. The plant particles were bond by different methods:- * without addition of any adhesive. In that case water was sprayed on the plant particles before the forming process and was evaporated during the thermocompression. It leads to extraction of soluble and lignocellulosic compounds from the agroresources that can act as adhesives.- * with addition of a biobased adhesive based on casein, the protein from bovine milk, or based on a commercial caseinate, added at different ratios to the plant particles.- The effect of the type of agroresources, the particle size, the formulation of the biosourced adhesive, and its application are evaluated testing the physico-chemical properties of the particleboards: mechanical properties (bending test and internal bond), thermal properties, and behavior towards water and fire. Using a biobased adhesive improves the mechanical properties of the particleboards significantly compared to the version without added adhesive. Panels made with flax shives generally showed better properties than with sunflower bark, so flax shives seem more suitable for particleboard manufacturing. But after optimization of the formulation and the process, both raw materials could be used with casein-based adhesive yielding efficient and fully biobased particleboards for applications such as furniture or door panels

Soft interface dynamics in flax-fabrics/epoxy composites

International audienc

La nano-indentation, le gonflement de film et la flexion de poutre ; trois essais complémentaires pour caractériser les propriétés mécaniques des matériaux en faibles épaisseurs. Application au cas du Nickel électrodéposé

Dans le contexte de la science des matériaux en faibles dimensions qui s'évertue à comprendre le comportement thermomécanique des matériaux utilisés dans la réalisation des micro-dispositifs, on présente trois techniques expérimentales complémentaires permettant de quantifier, via des calculs numériques par la technique des E.F., les comportements élastique et inélastique de la matière. On présente une application de ces techniques, à savoir : la nano-indentation, le gonflement de films minces et la flexion de poutres, au cas du Nickel électrodéposé. On en déduit les évolutions du module d'Young, des contraintes résiduelles, de la dureté et des paramètres d'écrouissage en fonction de la nature du substrat et de la densité du courant d'électrodéposition

Morphology, static and fatigue behavior of a natural UD composite: The date palm petiole ‘wood’

International audienc

Influence of water ageing on mechanical properties and damage events of two reinforced composite materials: Flax–fibres and glass–fibres

International audienceMoisture absorption and durability in water environment are major concerns for natural fibres as reinforcement in composites. This paper presents a study on the influence of water ageing on mechanical properties and damage events of flax–fibre composites, compared with glass–fibre composites. The effects of the immersion treatment on the tensile characteristics, water absorption and acoustic emission (AE) recording were investigated. The water absorption results for the flax–fibre composites show that the evolution appears to be Fickian and the saturated weight gain is 12 times as high that the glass–fibre composites. Decreasing continuously with increasing water immersion time, the tensile modulus and the failure strain of flax–fibre composites are hardly affected by water ageing whereas only the tensile stress is reduced regarding the glass–fibre composites. AE indicate that matrix–fibres interface weakening is the main damage mechanism induced by water ageing for both composites

Mesure de l’efficacité de la lutte contre l’ambroisie : étude de faisabilité

National audienceCommon ragweed (Ambrosia artemisiifolia L.) is known for its high allergenic pollens and by the difficulty to control this invasive plant which make it a problem for public health and is a harmfulness in rural areas. This first work aims to make a feasibility study to verify the proper functioning of selected traps and the correct implementation of specific procedures. It was decided to use passive traps SIGMA2 (SIGMA2 Like Trap ou SLT). Two geographical areas were selected, each with 4 traps: an infested area in Isère and a slightly infested area in Côte d'Or. SLT traps used can well collect pollen from local areas, the collected quantities vary in a corresponding manner according to the degree of infestation by the plant and comparison with pollen counts of downhole traps is concordant in terms of time. This feasibility study confirms the interest of using SLT traps to measure the effectiveness of the implementation of the procedure of fight against ragweed.L’ambroisie (Ambrosia artemisiifolia L.) est connue pour son pollen à fort potentiel allergisant et par la difficulté de contrôler son implantation, son côté plante invasive en fait un problème de santé publique et une nuisibilité pour le monde agricole. Ce premier travail a pour objectif de valider les capteurs choisis et les procédures spécifiques pour mesurer l’efficacité de la lutte contre l’ambroisie. Il a été choisi d’utiliser les capteurs passifs de type SIGMA2 (SIGMA2 Like Trap ou SLT). Deux zones géographiques ont été choisies chacune avec 4 capteurs : une zone infestée en Isère et une zone peu touchée en Côte d’or. Les capteurs SLT utilisés permettent bien de recueillir les pollens d’origine locale, les quantités recueillies varient de façon concordante en fonction du degré d’infestation par la plante, la comparaison avec les comptes polliniques des capteurs de fond de type Hirst est concordante sur le plan temporel. Cette étude de faisabilité confirme l’intérêt de l’utilisation des capteurs SLT pour mesurer l’efficacité de la mise en oeuvre des moyens de lutte contre l’ambroisie