Recherche de nouveaux actifs d'origine microalgale d'intérêt en dermocosmétique : antiacnéens et conservateurs potentiels

Microalgae are well-known to produce many bioactive molecules which are used more and more in both pharmaceutical and agroalimentary companies. The aim of my PhD project was to discover antimicrobial activitiesof natural origin which may be used in cosmetic in particular as preservatives and antiacne. Culture media in stationary phase of growth of a 113 microalgae collection, cultivated in the laboratory, were harvested. The presence of antibacterial and / or antifungal activities was evaluated on different microorganisms. This screening allowed to isolate 5 microalgae secreting molecules inhibiting the growth of bacteria belonging to Salmonella, Staphylococcus and Propionibacterium genera. Then my work concerned the S555 microalgae which show a total inhibiton activity of the growth on 3 Gram + bacteria : S. aureus, S. epidermis and P. acnes, these 2 last species being involved in the acne disease. This microalgae was then cultivated in industrial condition in order to confirm these inhibitions. A widening of the action spectrum suggests that these activities are specific to Gram + bacteria. Moreover, the S555 active compound(s) present no cytotoxicity or irritability potential on fibroblasts in vitro,making them potentially usable in dermocosmetic. Lastly, a fractionation of the culture medium and biomass of S555 microalgae were performed to separate the active compound(s). Their characterization is currently in progress.Les microalgues sont bien connues pour produire de nombreuses molécules bioactives qui sont de plus en plus utilisées dans les industries pharmaceutiques et agroalimentaires. Mon projet de thèse avait pour but de mettre en évidence des activités antimicrobiennes d’origine naturelle valorisables en cosmétique notamment en tant que conservateurs et antiacnéens. Des milieux de culture en phase stationnaire de croissance d’une collection de 113 microalgues cultivées au sein du laboratoire ont été prélevés. La présence d’activités antibactérienne et / ou antifongique a été évaluée sur différents microorganismes modèles. Ce criblage m’a permis d’isoler 5 microalgues sécrétant des molécules inhibant la croissance de bactéries appartenant aux genres Salmonella, Staphylococcus et Propionibacterium. La suite de mon travail a porté sur la microalgue référencée S555 qui montre une activité d’inhibiton totale de la croissance de 3 bactéries Gram + : S. aureus, S. epidermis et P. acnes, ces 2 dernières espèces étant impliquées dans l’acné. Cette microalgue a alors été mise en culture en pilote pré-industriel afin de confirmer ces inhibitions. Un élargissement du spectre d’action suggère que ces activités sont spécifiques des bactéries Gram positives. De plus, le(s) composé(s) actif(s) de S555 ne présente(nt) aucune cytotoxicité ou potentiel irritant sur des fibroblastes en culture, les rendant potentiellement utilisables en dermocosmétique. Enfin, un fractionnement du milieu de culture et de la biomasse de cette microalgue a été mis en oeuvre pour séparer le(s) composé(s) actif(s). Leur caractérisation est actuellement en cours

Transition and control in rotating-disk boundary-layer

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Upregulation of PPARβ/δ Is Associated with Structural and Functional Changes in the Type I Diabetes Rat Diaphragm

Diabetes mellitus is associated with alterations in peripheral striated muscles and cardiomyopathy. We examined diaphragmatic function and fiber composition and identified the role of peroxisome proliferator-activated receptors (PPAR alpha and beta/delta) as a factor involved in diaphragm muscle plasticity in response to type I diabetes.Streptozotocin-treated rats were studied after 8 weeks and compared with their controls. Diaphragmatic strips were stimulated in vitro and mechanical and energetic variables were measured, cross bridge kinetics assessed, and the effects of fatigue and hypoxia evaluated. Morphometry, myosin heavy chain isoforms, PPAR alpha and beta/delta gene and protein expression were also assessed. Diabetes induced a decrease in maximum velocity of shortening (-14%, P<0.05) associated with a decrease in myosin ATPase activity (-49%, P<0.05), and an increase in force (+20%, P<0.05) associated with an increase in the number of cross bridges (+14%, P<0.05). These modifications were in agreement with a shift towards slow myosin heavy chain fibers and were associated with an upregulation of PPARbeta/delta (+314% increase in gene and +190% increase in protein expression, P<0.05). In addition, greater resistances to fatigue and hypoxia were observed in diabetic rats.Type I diabetes induced complex mechanical and energetic changes in the rat diaphragm and was associated with an up-regulation of PPARbeta/delta that could improve resistance to fatigue and hypoxia and favour the shift towards slow myosin heavy chain isoforms

Search of new active compounds from microalgae for dermocosmetic application : antiacne and potential preservatives

Les microalgues sont bien connues pour produire de nombreuses molécules bioactives qui sont de plus en plus utilisées dans les industries pharmaceutiques et agroalimentaires. Mon projet de thèse avait pour but de mettre en évidence des activités antimicrobiennes d’origine naturelle valorisables en cosmétique notamment en tant que conservateurs et antiacnéens. Des milieux de culture en phase stationnaire de croissance d’une collection de 113 microalgues cultivées au sein du laboratoire ont été prélevés. La présence d’activités antibactérienne et / ou antifongique a été évaluée sur différents microorganismes modèles. Ce criblage m’a permis d’isoler 5 microalgues sécrétant des molécules inhibant la croissance de bactéries appartenant aux genres Salmonella, Staphylococcus et Propionibacterium. La suite de mon travail a porté sur la microalgue référencée S555 qui montre une activité d’inhibiton totale de la croissance de 3 bactéries Gram + : S. aureus, S. epidermis et P. acnes, ces 2 dernières espèces étant impliquées dans l’acné. Cette microalgue a alors été mise en culture en pilote pré-industriel afin de confirmer ces inhibitions. Un élargissement du spectre d’action suggère que ces activités sont spécifiques des bactéries Gram positives. De plus, le(s) composé(s) actif(s) de S555 ne présente(nt) aucune cytotoxicité ou potentiel irritant sur des fibroblastes en culture, les rendant potentiellement utilisables en dermocosmétique. Enfin, un fractionnement du milieu de culture et de la biomasse de cette microalgue a été mis en oeuvre pour séparer le(s) composé(s) actif(s). Leur caractérisation est actuellement en cours.Microalgae are well-known to produce many bioactive molecules which are used more and more in both pharmaceutical and agroalimentary companies. The aim of my PhD project was to discover antimicrobial activitiesof natural origin which may be used in cosmetic in particular as preservatives and antiacne. Culture media in stationary phase of growth of a 113 microalgae collection, cultivated in the laboratory, were harvested. The presence of antibacterial and / or antifungal activities was evaluated on different microorganisms. This screening allowed to isolate 5 microalgae secreting molecules inhibiting the growth of bacteria belonging to Salmonella, Staphylococcus and Propionibacterium genera. Then my work concerned the S555 microalgae which show a total inhibiton activity of the growth on 3 Gram + bacteria : S. aureus, S. epidermis and P. acnes, these 2 last species being involved in the acne disease. This microalgae was then cultivated in industrial condition in order to confirm these inhibitions. A widening of the action spectrum suggests that these activities are specific to Gram + bacteria. Moreover, the S555 active compound(s) present no cytotoxicity or irritability potential on fibroblasts in vitro,making them potentially usable in dermocosmetic. Lastly, a fractionation of the culture medium and biomass of S555 microalgae were performed to separate the active compound(s). Their characterization is currently in progress

Combinatorial approach to chiral tris-ligated carbophilic platinum complexes: application to asymmetric catalysis

A straightforward methodology for the synthesis of libraries of chiral tris-ligated cationic platinum complexes and their in situ evaluation as asymmetric carbophilic catalysts in a model domino hydroarylation/cyclization reaction of a 1,6-enyne was developed. A catalyst-generation process based on a combination of a monodentate and a bidentate phosphorus ligand allowed the formation of 108 chiral complexes. One-pot screening of the stereoinduction obtained with this library in a test domino addition/cyclization reaction validated this approach and stressed the key role played by the monodentate ligand partner in obtaining high enantioselectivities. In the case of two challenging substrate/nucleophile combinations, the combinatorial approach resulted in a significant gain in enantioselectivity

ESPON TEDI - Territorial Diversity in Europe

Main areas of analysis: - Identification of the particular territorial specificities that the territories under investigation (mountain, island and sparsely populated and peripheral areas) are subject to. - Analysis of the chain of causalities between these territorial specificities and the constraints and opportunities they lead to in terms of facilitating economic and social development. - Identification of the comparative advantages of these regions by emphasising their specific development opportunities, i.e. not shared with other types of territories. - Investigation of the temporal change linked to the impacts of current macro-trends on these territories, highlighting their degree of vulnerability to external factors. - Identification of the key levers available for future policy actions aiming to take full advantage of the specific potentials of the concerned territories and counterbalancing social and economic trends that could hamper or block development

Gold imidazolium-based ionic liquids, efficient catalysts for cycloisomerization of gamma-acetylenic carboxylic acids

International audienc

Utilisation de la spectrométrie Raman dans le domaine pharmaceutique

This document sets out the theoretical and practical fundamentals to guide users in the imple- mentation of Raman spectroscopy in industry or the university-hospital sector. It describes the principle of this technique and currently available instruments. Since Raman spectrometers are used in a regulated context, the methodology of instru- ment qualification is discussed. Different types of applications encountered in the pharmaceutical field are presented: process monitoring, searching for and detecting counterfeits, and identifying raw materials on receipt

Chemical Imagnig: An essential mechanism to assess pharmaceutical quality (Part II)

This article is intended to report on the contribution of chemical imaging to the professions of pharmacy, bio-pharmacy or of cosmetics, whether during the phase of the search for an active substance (experimental pharmacology), in development of a formulation or of quality control, or as an additional tool in resolution of problems of quality in industrial manufacture. It has been written for a reader who is little familiar with this method in order to provide him/her with the methodological bases and important points to monitor in order to draw the best possible results from it. Chemical imaging to date is the only tool which enables to visualise without labelling the spatial configuration of chemical (or biochemical) species in a sample. It is an essential added value in comparison to optical microscopy