54 research outputs found

    Comparison of Three Processes for Parenteral Nanoemulsion Production: Ultrasounds, Microfluidizer, and Premix Membrane Emulsification

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    International audienceNanoemulsions are of great interest for pharmaceutical applications, including parenteral dosage forms. However, their production is still limited and requires more efficient and adaptive technologies. The more common systems are high-shear homogenization like microfludizers (MF) at industrial scale and ultrasounds at research scale, both based on high energy limiting their application for sensitive drugs. Recently, a process based on premix membrane emulsification (PME) was developed to produce nanoemulsions. These three processes have been compared for the production of a model parenteral nanoemulsion containing all-trans-retinoic acid, a thermolabile molecule which is used in the treatment of acute promyelocytic leukemia in a parenteral form. Droplet size and active integrity were studied because of their major interest for efficacy and safety assessment. Regarding droplet size, PME produced monodispersed droplets of 335 nm compared to the other processes which produced nanoemulsions of around 150 nm but with the presence of micron size droplets detected by laser diffraction and optical microscopy. No real difference between the three processes was observed on active degradation during emulsifcation. However, regarding stability, especially at 40 o C nanoemulsions obtained with the microfluidizer showed a greater molecule degradation and unstable nanoemulsion with a 4 times droplet size increase under stress conditions

    Sphingosine Kinase 1 and Sphingosine 1-Phosphate Receptor 3 Are Functionally Upregulated on Astrocytes under Pro-Inflammatory Conditions

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    Background: Reactive astrocytes are implicated in the development and maintenance of neuroinflammation in the demyelinating disease multiple sclerosis (MS). The sphingosine kinase 1 (SphK1)/sphingosine1-phosphate (S1P) receptor signaling pathway is involved in modulation of the inflammatory response in many cell types, but the role of S1P receptor subtype 3 (S1P(3)) signaling and SphK1 in activated rat astrocytes has not been defined.Methodology/Principal Findings: Using immunohistochemistry we observed the upregulation of S1P(3) and SphK1 expression on reactive astrocytes and SphK1 on macrophages in MS lesions. Increased mRNA and protein expression of S1P(3) and SphK1, as measured by qPCR and Western blotting respectively, was observed after treatment of rat primary astrocyte cultures with the pro-inflammatory stimulus lipopolysaccharide (LPS). Activation of SphK by LPS stimulation was confirmed by SphK activity assay and was blocked by the use of the SphK inhibitor SKI (2-(p-hydroxyanilino)-4-(p-chlorphenyl) thiazole. Treatment of astrocytes with a selective S1P(3) agonist led to increased phosphorylation of extracellular signal-regulated kinase (ERK)-1/2), which was further elevated with a LPS pre-challenge, suggesting that S1P(3) upregulation can lead to increased functionality. Moreover, astrocyte migration in a scratch assay was induced by S1P and LPS and this LPS-induced migration was sensitive to inhibition of SphK1, and independent of cell proliferation. In addition, S1P induced secretion of the potentially neuroprotective chemokine CXCL1, which was increased when astrocytes were pre-challenged with LPS. A more prominent role of S1P(3) signaling compared to S1P(1) signaling was demonstrated by the use of selective S1P(3) or S1P(1) agonists.Conclusion/Significance: In summary, our data demonstrate that the SphK1/S1P(3) signaling axis is upregulated when astrocytes are activated by LPS. This signaling pathway appears to play a role in the establishment and maintenance of astrocyte activation. Upregulation of the pathway in MS may be detrimental, e. g. through enhancing astrogliosis, or beneficial through increased remyelination via CXCL1

    Production of food nanomaterials by specialized equipment

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    In the past decade, there has been a great interest in using nanotechnology by different industries, including food, pharmaceutical, and beauty. Nanotechnology provides many advantages to produce functional compounds which tend to be delivered for desired properties, such as protection from the environment or food matrix, controlled release, and increased bioavailability and bioaccessibility (Muhammad et al., 2019, Sedaghat Doost et al., 2019b, Sedaghat Doost et al., 2018c). There is a variety of methods to prepare food nanomaterials. Specialized equipment is frequently employed for the production of efficient nano-delivery systems, which is the focus of this chapter; the basic principle of conventional and recent techniques, as well as their advantages and disadvantages are described

    Design and modelling of High Energetic Materials (HEM) in accordance with environmentals and regulatories contraints

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    Depuis deux décennies, la recherche militaire se focalise sur l'amélioration des critÚres de performances des explosifs, tout en prenant en compte leurs impacts environnementaux et toxicologiques. Ces enjeux sont encadrés par une réglementation stricte : REACh (Registration, Evaluation, Authorization and Restriction of Chemicals) permettant d'assurer un haut niveau de protection sanitaire et environnementale. De nos jours, développer des explosifs ou molécules hautement énergétiques (High Energy Materials (HEM)) ayant un effet réduit sur l'homme et l'environnement est un sujet de préoccupation majeur. Ainsi, en collaboration avec Airbus Safran Lauchers (ASL), un programme de recherche a été mis en place, afin d'obtenir des outils optimisés pour la prédiction de la toxicité des HEMs et concevoir de nouvelles molécules HEMS non toxiques et réglementaires.Différentes méthodes in silico ont été utilisées dont des Relations Structure Activité Quantitatives (ou Quantitative Structure-Activity Relationship (QSAR)) et le Machine Learning. La recherche de similarité structurale parmi les molécules est un outil novateur sur lequel nous avons basé nos prédictions in silico. Cette similarité est obtenue grùce à un algorithme intelligent développé au sein du PÎle RhÎne Alpin de Bio-Informatique de Lyon et qui a donné lieu à un brevet. Cet algorithme nous permet d'obtenir des prédictions plus précises basées sur des données expérimentales issues de directives européennesFor the last two decades, the military research has focused on the improvement of explosive performances, while taking into account their environmental and toxicological impacts. These issues are governed by strict regulations: REACh (Registration, Evaluation, Authorization and Restriction of Chemicals) to ensure a high level of health and environmental protection.Today, it's a major consideration to develop High Energetic Materials (HEM) or molecules who's hazard on human health and environment are reduced. Thus, in collaboration with Airbus Safran Lauchers (ASL), a research program was set up to obtain optimized tools for predicting the potential toxicity of HEM and to design new non-toxic and regulatory molecules.Different in silico methods have been used, including Quantitative Structure Activity Activity Relationships (QSARs) and Machine Learning.The search for structural similarity among molecules is an innovative tool on which we based our predictions in silico. This similarity is obtained thanks to an intelligent algorithm developed within the Pole Rhone Alpin de Bio-Informatique of Lyon which gave rise to a patent. This algorithm allows us to obtain more accurate predictions based on experimental data from European directive

    Développement et valorisation d'un procédé d'émulsification membranaire pour la production de nanoémulsions

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    Nanoemulsions are interesting carriers for applications such as cosmetics, pharmaceutical and food. They are produced usually by low or high energy techniques. In this work, a process involving moderate pressure, premix membrane emulsification (PME) was proposed as an alternative. Oil-in-water (O/W) and water-in-oil (W/O) nanoemulsions were produced with a pilot scale set-up composed of a controlled high pressure syringe pump and Shirasu Porous Glass (SPG) membrane. First, the influence of process and composition parameters on droplet sizes and pressures was extensively studied with model compositions to optimize the production. Thus, nanoemulsions down to 260 nm for O/W and around 600 nm for W/O were successfully produced. Then, the set-up was used to produce nanoemulsions of specific compositions: O/W and W/O nanoemulsions stabilized with polypeptidic surfactants and O/W nanoemulsions suitable for injection. Finally, the set-up developed was compared to two traditional high energy processes, microfludizer and ultrasound in terms of droplet size and active preservation. No real difference between the three processes was seen on active preservation with the model active chosen. However, regarding droplet size, PME produced monodispersed droplets of 335 nm compared to the other processes which produced nanoemulsions of around 150 nm but with the presence of micron size droplets detected by laser diffraction and optical microscopy. Therefore, PME nanoemulsions are also suitable for parenterals applications with no additional filtration step requiredLes nanoĂ©mulsions sont des formulations intĂ©ressantes pour des applications telles que les cosmĂ©tiques, les produits pharmaceutiques et les produits alimentaires. Elles peuvent ĂȘtre produites par des techniques Ă  basse ou haute Ă©nergie. Dans ce travail, un procĂ©dĂ© impliquant une pression modĂ©rĂ©e, l'Ă©mulsification membranaire par prĂ©mix a Ă©tĂ© proposĂ© comme alternative. Des nanoĂ©mulsions huile-dans-eau (H/E) et eau-dans-huile (E/H) ont Ă©tĂ© produites avec une installation Ă  l'Ă©chelle pilote composĂ©e d'un pousse-seringue Ă  haute pression et d'une membrane Shirasu Porous Glass (SPG). Tout d'abord, l'influence des nombreux paramĂštres de procĂ©dĂ© et de composition sur la taille des gouttelettes et la pression rĂ©sultante a Ă©tĂ© Ă©tudiĂ©e avec des compositions modĂšles afin d'optimiser la production. Ainsi, des nanoĂ©mulsions H/E d'environ 260 nm et E/H d'environ 600 nm ont Ă©tĂ© produites avec succĂšs. Puis, le montage a Ă©tĂ© utilisĂ© pour produire des nanoĂ©mulsions de compositions spĂ©cifiques, des nanoĂ©mulsions H/E et E/H stabilisĂ©es avec des tensioactifs polypeptidiques et une nanoĂ©mulsion H/E adaptĂ©e Ă  l'injection. Enfin, le procĂ©dĂ© dĂ©veloppĂ© a Ă©tĂ© comparĂ© Ă  deux procĂ©dĂ©s Ă  haute Ă©nergie traditionnels, le microfludiseur et les ultrasons en termes de taille des gouttelettes et de conservation d'actifs. Aucune diffĂ©rence entre les procĂ©dĂ©s n'a Ă©tĂ© observĂ©e en ce qui concerne la prĂ©servation de l'acif choisi. Cependant, en ce qui concerne la taille, les nanoĂ©mulsions produites par les membranes ont prĂ©sentĂ© des gouttelettes monodisperses de 335 nm par rapport aux autres procĂ©dĂ©s qui ont produit des nanoĂ©mulsions d'environ 150 nm de taille moyenne mais contenant aussi des gouttelettes de taille micromĂ©trique dĂ©tectĂ©es par diffraction laser et microscopie optique. Pour cette raison, les nanoĂ©mulsions produites par procĂ©dĂ© membranaire conviennent Ă©galement pour des applications parentĂ©rales sans Ă©tape de filtration supplĂ©mentair

    Conception et modélisation de nouvelles molécules hautement énergétiques en fonction des contraintes réglementaires et environnementales

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    For the last two decades, the military research has focused on the improvement of explosive performances, while taking into account their environmental and toxicological impacts. These issues are governed by strict regulations: REACh (Registration, Evaluation, Authorization and Restriction of Chemicals) to ensure a high level of health and environmental protection.Today, it's a major consideration to develop High Energetic Materials (HEM) or molecules who's hazard on human health and environment are reduced. Thus, in collaboration with Airbus Safran Lauchers (ASL), a research program was set up to obtain optimized tools for predicting the potential toxicity of HEM and to design new non-toxic and regulatory molecules.Different in silico methods have been used, including Quantitative Structure Activity Activity Relationships (QSARs) and Machine Learning.The search for structural similarity among molecules is an innovative tool on which we based our predictions in silico. This similarity is obtained thanks to an intelligent algorithm developed within the Pole Rhone Alpin de Bio-Informatique of Lyon which gave rise to a patent. This algorithm allows us to obtain more accurate predictions based on experimental data from European directivesDepuis deux décennies, la recherche militaire se focalise sur l'amélioration des critÚres de performances des explosifs, tout en prenant en compte leurs impacts environnementaux et toxicologiques. Ces enjeux sont encadrés par une réglementation stricte : REACh (Registration, Evaluation, Authorization and Restriction of Chemicals) permettant d'assurer un haut niveau de protection sanitaire et environnementale. De nos jours, développer des explosifs ou molécules hautement énergétiques (High Energy Materials (HEM)) ayant un effet réduit sur l'homme et l'environnement est un sujet de préoccupation majeur. Ainsi, en collaboration avec Airbus Safran Lauchers (ASL), un programme de recherche a été mis en place, afin d'obtenir des outils optimisés pour la prédiction de la toxicité des HEMs et concevoir de nouvelles molécules HEMS non toxiques et réglementaires.Différentes méthodes in silico ont été utilisées dont des Relations Structure Activité Quantitatives (ou Quantitative Structure-Activity Relationship (QSAR)) et le Machine Learning. La recherche de similarité structurale parmi les molécules est un outil novateur sur lequel nous avons basé nos prédictions in silico. Cette similarité est obtenue grùce à un algorithme intelligent développé au sein du PÎle RhÎne Alpin de Bio-Informatique de Lyon et qui a donné lieu à un brevet. Cet algorithme nous permet d'obtenir des prédictions plus précises basées sur des données expérimentales issues de directives européenne
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