Développement de matériaux poreux hybrides innovants pour l'analyse glycomique

International audienceL'analyse glycomique consiste à établir le profil des oligosaccharides présents sur l'ensemble des glycoprotéines d'un fluide biologique d'intérêt (ex : plasma) . Cependant, la préparation des échantillons implique de nombreuses étapes souvent manuelles, très chronophages et peu compatibles avec l'analyse à haut débit des échantillons. Les matériaux préparés selon le procédé sol-gel, par leur grande adaptabilité en terme de porosité et de propriétés physico-chimiques, ont montré qu'ils pouvaient être utilisés pour une grande variété d'applications tels que la détection (capteurs) ou la capture de molécules d'intérêt , notamment dans le domaine biomédical. Dans cette optique, nous développons des matériaux à porosité bimodale pour faciliter et accélérer la préparation des échantillons dédiés à l'analyse glycomique. Les premiers résultats obtenus seront présentés, en particulier le procédé de synthèse, les modulations possibles des matériaux (microstructure et porosité) ainsi que la caractérisation de leurs propriétés texturales et microstructurales. Enfin, quelques résultats prometteurs obtenus à l'aide de ces matériaux sur des échantillons biologiquement pertinents seront également présentés

Innovative porous materials for enhanced glycomic analysis

International audienceHierarchical porosity sol-gel monoliths (HPMs) are of increasing interest for a wide variety of applications due to their outstanding microstructural (homogenous) and textural properties (high porosity and specific surface area) [1]. The high flow rate and low-pressure resultant compared to conventional materials, makes them suited for extraction and enrichment of analytes of interest in analytical techniques (HPLC, SPE, etc.) [2–4]. However, pure inorganic materials have rarely been considered for relevant applications in various omics fields such as metabolomics or proteomics [5].In the context, we report on: (i) a pure silica HPM based on a finely tuned bimodal porosity thoroughly controlled, (ii) coupled to a new way to a miniaturize shaping (iii) and its use as an innovative tool for sample preparation prior to glycan analysis by mass spectrometry, as a new source of disease biomarkers (glycomics analysis). The monolith synthesis will be presented with a special emphasize on its robustness and on the modulations of the bimodal porosity obtained ([0.1–5] μm and [1-25] nm). Beside microstructural and textural properties measurements (SEM, Hg porosimetry, etc.), the transport of small molecules through mesoporous network were evaluated by TEM tomography. Finally, the material was processed in different shapes and size (50 μm – 4 mm in diameter) demonstrating a high flexibility of our approach to produce devices dedicated to a biological analysis. The use of HPM for the analysis of both free and protein-bound oligosaccharides present in precious samples (human blood and milk) and their detection by MALDI-TOF mass spectrometry will be presented as a proof of concept. Optimized experimental conditions, as well as material textures and shapes, enabled straightforward and time-efficient purification and MS- based glycomics analysis using minute quantities (few μl) of solvents but above all of complex human biofluids, thus outperforming common laboratory protocols

Innovative porous materials for enhanced glycomic analysis

International audienceHierarchical porosity sol-gel monoliths (HPMs) are of increasing interest for a wide variety of applications due to their outstanding microstructural (homogenous) and textural properties (high porosity and specific surface area) [1]. The high flow rate and low-pressure resultant compared to conventional materials, makes them suited for extraction and enrichment of analytes of interest in analytical techniques (HPLC, SPE, etc.) [2–4]. However, pure inorganic materials have rarely been considered for relevant applications in various omics fields such as metabolomics or proteomics [5].In the context, we report on: (i) a pure silica HPM based on a finely tuned bimodal porosity thoroughly controlled, (ii) coupled to a new way to a miniaturize shaping (iii) and its use as an innovative tool for sample preparation prior to glycan analysis by mass spectrometry, as a new source of disease biomarkers (glycomics analysis). The monolith synthesis will be presented with a special emphasize on its robustness and on the modulations of the bimodal porosity obtained ([0.1–5] μm and [1-25] nm). Beside microstructural and textural properties measurements (SEM, Hg porosimetry, etc.), the transport of small molecules through mesoporous network were evaluated by TEM tomography. Finally, the material was processed in different shapes and size (50 μm – 4 mm in diameter) demonstrating a high flexibility of our approach to produce devices dedicated to a biological analysis. The use of HPM for the analysis of both free and protein-bound oligosaccharides present in precious samples (human blood and milk) and their detection by MALDI-TOF mass spectrometry will be presented as a proof of concept. Optimized experimental conditions, as well as material textures and shapes, enabled straightforward and time-efficient purification and MS- based glycomics analysis using minute quantities (few μl) of solvents but above all of complex human biofluids, thus outperforming common laboratory protocols

Le risque de dégradation de la qualité de l'eau des lacs de la réserve naturelle de Kurtna (Estonie) : le cas de la température et de l'oxygène dissous

International audienceEnvironmental risk about water quality of lakes in Kurtna landscape reserve (Estonia) by the study of water temperature and dissolved oxygen. The Kurtna reserve (North-Eastern Estonia) includes about forty lakes of hydro-glacial origin, among which the most are kettle hole lakes. Their level and the quality of water are conditioned by aquifers, which are threatened by industrial activities (sand quarry, peat production and oil shale excavation). The paper presents results of a field campaign in March 2013, for measuring water temperature, dissolved oxygen and salinity in two ice-covered lakes (Martiska and Nõmme). Martiska is a closed lake. A large (from 0 °C to 4 °C) inverse thermal stratification takes place under the ice. The very thick anoxic layer may be caused by the cumulating effect of the ice barrier and the consumption in a rich in organic matter lake. Nõmme fits in a hydrographical chain with tributaries and an emissary. The inverse thermal stratification is disturbed by a well delimited mid-layer. Temperature, dissolved oxygen and salinity show that it is probably the fluvial water body, which has entered the lake. The hypothesis is confirmed by the study of the river plume. This inflow is rich in dissolved oxygen. We may suggest, that the lakes with an affluent are less threatened by the winter lack of oxygen than the closed lakes of the region

Fresh water and sediment discharges variability to the coasts of Maghreb: the impact of climate change and anthropogenic activities on coastal environments

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