Rheumatoid synovitis is infiltrated by immune cells that interact with synoviocytes, leading to the pannus formation. Inflammation or cell interaction effects are mainly evaluated with cytokine ...production, cell proliferation or migration. Few studies interest on cell morphology. Here, the purpose was to deepen some morphological changes of synoviocytes or immune cells under inflammatory conditions. Inflammatory cytokines, IL-17 and TNF that are largely involved in RA pathogenesis, induced a change in synoviocyte morphology, inducing a retracted cell with higher number of pseudopodia. Several morphological parameters decreased in inflammatory conditions: cell confluence, area and motility speed. The same impact on cell morphology was observed in co-culture of synoviocytes and immune cells in inflammatory/non-inflammatory conditions or with cell activation (miming the in vivo situation), affecting both cell types: synoviocytes were retracted and inversely immune cells proliferated, indicating that cell activation induced a morphological change of cells. In contrast, with RA but not control synoviocytes, cell interactions were not sufficient to affect PBMC and synoviocyte morphology. The morphological effect came only from the inflammatory environment. These findings reveal that the inflammatory environment or cell interactions induced massive changes in control synoviocytes, with cell retraction and increase of pseudopodia number, leading to better interactions with other cells. Except in the case of RA, the inflammatory environment was absolutely required for such changes.
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•Inflammatory environment or cell interactions induced massive changes in control synoviocytes.•Retracted synoviocytes with an increase of pseudopodia lead to better interactions with other cells.•PBMC proliferated, appeared deformed or even fused to the synoviocytes.•In RA case, the inflammatory environment was absolutely required for such changes.•These findings can be used as a diagnostic tool, especially to detect activated and pathological cells.
Objective
Pickering emulsions are increasingly used in the pharmaceutical and cosmetic fields, especially for topical applications, since these systems require solid particles as emulsifiers instead ...of surfactants which are known to cause skin irritation. The solid inorganic nanoparticles (TiO2 and ZnO) used as UV filters in sunscreen formulations may also stabilize emulsion droplets, so that the utility of surfactants may be questioned. Surfactant‐free sunscreen emulsions solely stabilized by such nanoparticles (NPs) have been studied.
Methods
The ability of these NPs to stabilize o/w emulsions containing a ‘model’ oil phase, the C12‐C15 alkylbenzoate, has been assessed. ZnO and hydrophilic silica‐coated TiO2 NPs widely used in sunscreen products were used together with their mixtures. The emulsification efficiency, the control of droplet size and the stability of o/w Pickering emulsions solely stabilized by NPs were investigated. A ZnO/TiO2 NPs mixture characterized by a theoretical SPF of 45 was finally used as unique emulsifiers to develop a surfactant‐free sunscreen emulsion.
Results
Stable Pickering emulsions containing 10 up to 60 wt% of C12‐C15 alkyl benzoate were formulated with 2 wt% ZnO in the aqueous phase. The droplet size was controlled by the solid NPs content with respect to oil and the emulsification process. Hydrophilic TiO2 NPs did not allow the stabilization of emulsions. The substitution of TiO2 for ZnO up to 60–70 wt% in a 20/80 o/w emulsion was successfully performed. Finally, a ZnO/TiO2 NP mixture was tested as unique emulsifier system for the formulation of a sunscreen cream. Despite a lower viscosity, the obtained Pickering emulsion was stable and exhibited a photoprotective effect similar to the corresponding surfactant‐based sunscreen cream with an in vitro SPF of about 45.
Conclusion
Surfactant‐free Pickering emulsions can be stabilized by the UV‐filter nanoparticles for the manufacture of sunscreen products.
Resume
Objectifs
Les émulsions de Pickering sont de plus en plus utilisées dans les domaines pharmaceutique et cosmétique, notamment pour les applications topiques, car ces systèmes utilisent des particules solides comme émulsifiants au lieu de tensioactifs qui sont connus pour provoquer des irritations cutanées. Les nanoparticules inorganiques solides (TiO2 et ZnO) utilisées comme filtres UV dans les formulations d'écran solaire peuvent également stabiliser les gouttelettes d'émulsion, de sorte que l'utilité des tensioactifs peut être remise en question. Des émulsions de protection solaire sans tensioactifs et uniquement stabilisées par de telles nanoparticules (NP) ont été étudiées.
Méthodes
La capacité de ces NP à stabiliser les émulsions H/E contenant une phase huileuse «modèle», le benzoate d’alkyle C12‐C15, a été évaluée. Des NP de ZnO et de TiO2 couvert de silice hydrophile, que l’on trouve largement dans les produits de protection solaire, ont été utilisées séparément et en mélange. L'efficacité d'émulsification, le contrôle de la taille des gouttelettes et la stabilité des émulsions de Pickering H/E uniquement stabilisées par les NP ont été étudiés. Un mélange de NP ZnO/TiO2 caractérisé par un SPF théorique de 45 a finalement été utilisé comme émulsifiant unique pour développer une émulsion de protection solaire sans tensioactif.
Résultats
Des émulsions de Pickering stables contenant 10 à 60% en poids de benzoate d'alkyle C12‐C15 ont été formulées avec 2% en poids de ZnO dans la phase aqueuse. La taille des gouttelettes était contrôlée par la teneur en NP solides par rapport à l'huile et le procédé d'émulsification. Les NP de TiO2 hydrophile n'ont pas permis la stabilisation des émulsions. La substitution des NP de TiO2 par du ZnO jusqu'à 60–70% en poids dans une émulsion 20/80 H/E a été réalisée avec succès. Enfin, un mélange de NP ZnO/TiO2 a été testé en tant que système émulsifiant unique pour la formulation d'une crème solaire. Malgré une viscosité plus faible, l'émulsion de Pickering obtenue était stable et présentait un effet photoprotecteur similaire à la crème solaire à base de tensioactif correspondante avec un SPF in vitro d'environ 45.
Conclusion
Les émulsions Pickering sans tensioactifs peuvent être stabilisées par les nanoparticules de filtre UV pour la formulation de produits de protection solaire.
The morphology of fibroblast-like synoviocytes (FLS) issued from the synovial fluid (SF) of patients suffering from osteoarthritis (OA), rheumatoid arthritis (RA), or from healthy subjects (H), as ...well as the ultrastructure and mechanical properties of the FLS-secreted extracellular vesicles (EV), were analyzed by confocal microscopy, transmission electron microscopy, atomic force microscopy, and tribological tests. EV released under healthy conditions were constituted of several lipid bilayers surrounding a viscous inner core. This “gel-in” vesicular structure ensured high mechanical resistance of single vesicles and good tribological properties of the lubricant. RA, and to a lesser extent OA, synovial vesicles had altered morphology, corresponding to a “gel-out” situation with vesicles surrounded by a viscous gel, poor mechanical resistance, and poor lubricating qualities. When subjected to inflammatory conditions, healthy cells developed phenotypes similar to that of RA samples, which reinforces the importance of inflammatory processes in the loss of lubricating properties of SF.
Phage-derived therapies comprise phage therapy and the use of phage-derived proteins as anti-bacterial therapy. Bacteriophages are natural viruses that target specific bacteria. They were proposed to ...be used to treat bacterial infections in the 1920s, before the discovery and widespread over-commercialized use of antibiotics. Phage therapy was totally abandoned in Western countries, whereas it is still used in Poland, Georgia and Russia. We review here the history of phage therapy by focusing on bone and joint infection, and on the development of phage therapy in France in this indication. We discuss the rationale of its use in bacterial infection and show the feasibility of phage therapy in the 2020s, based on several patients with complex bone and joint infection who recently received phages as compassionate therapy. Although the status of phage therapy remains to be clarified by health care authorities, obtaining pharmaceutical-grade therapeutic phages (i.e., following good manufacturing practice guidelines or being "GMP-like") targeting bacterial species of concern is essential. Moreover, multidisciplinary clinical expertise has to determine what could be the relevant indications to perform clinical trials. Finally "phage therapy 2.0" has to integrate the following steps: (i) follow the status of phage therapy, that is not settled and defined; (ii) develop in each country a close relationship with the national health care authority; (iii) develop industrial-academic partnerships; (iv) create academic reference centers; (v) identify relevant clinical indications; (vi) use GMP/GMP-like phages with guaranteed quality bioproduction; (vii) start as salvage therapy; (vii) combine with antibiotics and adequate surgery; and (viii) perform clinical trials, to finally (ix) demonstrate in which clinical settings phage therapy provides benefit. Phage-derived proteins such as peptidoglycan hydrolases, polysaccharide depolymerases or lysins are enzymes that also have anti-biofilm activity. In contrast to phages, their development has to follow the classical process of medicinal products. Phage therapy and phage-derived products also have a huge potential to treat biofilm-associated bacterial diseases, and this is of crucial importance in the worldwide spread of antimicrobial resistance.
Background: Phage therapy a promising antimicrobial strategy to address antimicrobial resistance for infections caused by the major human pathogen Staphylococcus aureus. Development of therapeutic ...phages for human use should follow pharmaceutical standards, including selection of strictly lytic bacteriophages with high therapeutic potential and optimization of their production process. Results: Here, we describe three novel Silviavirus phages active against 82% of a large collection of strains (n = 150) representative of various methicillin-susceptible and -resistant S. aureus clones circulating worldwide. We also investigated the optimization of the efficiency and safety of phage amplification protocols. To do so, we selected a well-characterized bacterial strain in order to (i) maximize phage production yields, reaching phage titres of 1011 PFU/mL in only 4 h; and (ii) facilitate phage purity while minimizing the risk of the presence of contaminants originating from the bacterial host; i.e., secreted virulence factors or induced temperate phages. Conclusions: In sum, we propose a quality-by-design approach for the amplification of broad-spectrum anti-S. aureus phages, facilitating the subsequent steps of the manufacturing process; namely, purification and quality control.
The extraordinary potential of semiconductor quantum dots (QDs) has resulted in their widespread application in various fields, from engineering technology and the development of laboratory ...techniques to biomedical imaging and therapeutic strategies. However, the toxicity of QDs remains a concern and has limited their applications in human health. Better understanding of the behavior of QDs as it relates to their composition will enable the exploration of their limitations and development of a strategy to control their toxicity for potential therapeutic applications. Here, we describe approaches to minimize their toxicities according to the specific cell type, organ, or animal species, summarizing recent promising research at the cellular, organ, and whole-organism level.
Several excipients are commonly used to enhance the drug absorption through simple epithelia of the digestive tract. They permeate the paracellular barrier constituted by tight junctions (TJs). We ...compared the effects of two excipients, sodium caprate (C10) and a self‐emulsifying excipient Labrasol composed of a mixture of caprylocaproyl polyoxyl‐8 glycerides, both applied to emerged reconstructed human epidermis either ‘systemically’, that is by addition to the culture medium, or topically. During the ‘systemic’ application, which produced cytoplasmic translocation of occludin and leakage of the biotin marker into the lower stratum corneum, the decrease in the trans‐epithelial electrical resistance (TEER) was less abrupt with Labrasol when compared with C10, even though both excipients produced comparable final effects over time. With topical Labrasol, a significant TEER decrease was obtained with 5 times the ‘systemic’ concentrations. Topical application of C10 also resulted in the loss of the barrier function measured with TEER but had dramatic deleterious effects on the tissue morphology observed with light and electron microscopy. Our study demonstrates the potential value of Labrasol as an enhancer of bioavailability of molecules applied through the transcutaneous route. Our results suggest modulation of the epidermal TJs by both compounds. Even though the C10 action was at least partly due to overall cell damage and despite the fact that the decrease in TEER after topical application was apparently related to the permeabilization of the primary barrier of the stratum corneum in the first place.
Antioxidants provide the mainstay for skin protection against free radical damage. The structure of microemulsions (ME), colloidal thermodynamically stable dispersions of water, oil and surfactant, ...allows the incorporation of both lipophilic (vitamin E) and hydrophilic (vitamin C) antioxidants in the same system. The objective of this work was to investigate the potential of non-thickened (o/w, w/o and gel-like) and thickened (with colloidal silica) ME as carriers for the two vitamins using reconstructed human epidermis (RHE). The amounts of these vitamins accumulated in and permeated across the RHE were determined, together with factors affecting skin deposition and permeation. Notable differences were observed between formulations. The absorption of vitamins C and E in RHE layers was in general enhanced by ME compared to solutions. The incorporation of vitamins in the outer phase of ME resulted in greater absorption than that when vitamins were in the inner phase. The location of the antioxidants in the ME and affinity for the vehicle appear to be crucial in the case of non-thickened ME. Addition of thickener enhanced the deposition of vitamins E and C in the RHE. By varying the composition of ME, RHE absorption of the two vitamins can be significantly modulated.
: Several tight junction (TJ) proteins were detected in the living layers of adult human epidermis, and TJ‐like membrane ridges were observed at the top of the stratum granulosum (SG) in ...freeze‐fracture studies. We applied standard and immunoelectron microscopy to look for TJ‐derived structures in the stratum corneum (SC) of human adult epidermis and in cornified envelopes purified from the plantar SC. Besides confirming claudin‐1 labelling in the proximity of SG desmosomes, we also observed immunolocalization near corneodesmosomes in the lower SC. In addition, TJ proteins were consistently detected in the purified cornified envelopes. Lateral but not horizontal walls of the corneocytes showed frequent points of molecular fusion between lipid envelopes. These structural associations were very frequently localized at the top of the lateral corneocyte membranes, thus sealing the extremities of lateral intercorneocyte spaces. We propose that TJ‐like structures persist in the SC and contribute to the reinforcement of lateral contacts and to the formation of membrane interdigitations between corneocytes. Their presence could contribute to subdivision of the extracellular spaces of SC into consecutive individualized compartments. Intercellular lipids, enzymes and other (glyco)protein content could thus evolve in the keratinized epidermal layer at different paces, as preprogrammed in the underlying living cells and influenced by the environment, e.g. humidity. Such situation might explain differences in the degradation rates between the ‘peripheral’ and the ‘non‐peripheral’ corneodesmosomes observed during physiological desquamation, as previously suggested by us and others.
A new institutional clinical trial assessed the improvement of sleep disorders in 40 children with autism treated by immediate-release melatonin formulation in different regimens (0.5 mg, 2 mg, and 6 ...mg daily) for one month. The objectives of present study were to (i) prepare low-dose melatonin hard capsules for pediatric use controlled by two complementary methods and (ii) carry out a stability study in order to determine a use-bydate.Validation of preparation process was claimed as ascertained by mass uniformity of hard capsules.Multicomponent analysis by attenuated total reflectance Fourier transformed infrared (ATR-FTIR) of melatonin/microcrystalline cellulose mixture allowed to identify and quantify relative content of active pharmaceutical ingredients and excipients. Absolute melatonin content analysis by high performance liquidchromatography in 0.5 mg and 6 mg melatonin capsules was 93.6% ± 4.1% and 98.7% ± 6.9% of theoretical value, respectively. Forced degradation study showed a good separation of melatonin and its degradation products. The capability of the method was 15, confirming a risk of false negative < 0.01%. Stability test and dissolution test were compliant over 18 months of storage with European Pharmacopoeia. Preparation of melatonin hard capsules was completed manually and melatonin in hard capsules was stable for 18 months, in spite of low doses of active ingredient. ATR-FTIR offers a real alternative to HPLC for quality control of highdose melatonin hard capsules before the release of clinical batches.
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