Search

Essential oils are well known for their biological properties, making them useful for the treatment of various diseases. However, because of their poor stability and high volatility, their potential cannot be fully exploited. The use of nanoformulations to deliver essential oils can solve these critical issues and amplify their biological activities. We characterized an essential oil from Satureja thymbra via GC–MS and HPLC–DAD to provide qualitative and quantitative data. The essential oil was formulated in phospholipid vesicles which were characterized for size, surface charge, and storage stability. The entrapment efficiency was evaluated as the quantification of the major monoterpenoid phenols via HPLC–DAD. The morphological characterization of the vesicles was carried out via cryo-TEM and SAXS analyses. The essential oil's antioxidant potential was assayed via two colorimetric tests (DPPH• and FRAP) and its cytocompatibility was evaluated in HaCaT skin cell cultures. The results showed that the nanoformulations developed for the loading of S. thymbra essential oil were below 100 nm in size, predominantly unilamellar, stable in storage, and had high entrapment efficiencies. The vesicles also displayed antioxidant properties and high cytocompatibility. These promising findings pave the way for further investigation of the therapeutic potential of S. thymbra nanoformulations upon skin application. [ABSTRACT FROM AUTHOR]

The structures of fed state intestinal assemblies containing bile components, dietary fat, and fat-soluble vitamins are not well known, although they are involved in lipid transport. In this study, several methods were used to investigate structural transitions upon various dietary lipids or various fat-soluble vitamins incorporation in bile intestinal assemblies. In particular, DLS and turbidimetry were used to study transition points as a function of component concentration, and cryo-TEM and SAXS were used to resolve assembly structures at microscopic and supramolecular scales, respectively. Results showed that increasing the concentration of dietary lipids in bile assembly induced a transition from core-shell micelles to unilamellar vesicles (except with caprylate lipids, always yielding micelles). In these specific assemblies, increasing the concentration of a fat-soluble vitamin either induced a systematic structural transition, defining a solubilization capacity (α-tocopherol or phylloquinone), or induced a structural transition only in micelles (retinol), or did not induce any structural transition up to very high concentrations (cholecalciferol). Using SAXS data, ideal molecular organizations are proposed for assemblies in the absence or presence of α-tocopherol. [ABSTRACT FROM AUTHOR]

The structural organization of heterogeneous and multiphase natural aggregates depends on the biophysicochemical conditions prevailing in the environment, with major ions playing a crucial role. In this study, the impact of aluminum (Al) on iron-organic matter (Fe-OM) aggregates was investigated since Al can interact with OM and can be incorporated in Fe-oxyhydroxides or adsorbed on their surface. Mimetic environmental Fe-OM-Al aggregates were synthesized at various [Fe] and [Al] with a constant [OM]. At low [Al + Fe], Fe-OM-Al aggregates exhibit a colloidal behavior. Within the aggregates, Fe is present as Fe(III)-oligomers and ferrihydrite-like nanoparticles whereas Al forms monomers, oligomers and small polymers, all bound to OM. The Al and Fe phases interacted with each other. At high [Fe + Al], the Fe(III)-oligomers and Al monomers/oligomers polymerized which increases the size and quantity of the ferrihydrite-like nanoparticles and Al polymers and then branched out the OM, resulting in a large settling network. The effect of Al on the Fe-OM aggregates structure could also have an impact on the fate of pollutants. The occurrence of Al amorphous hydroxides and the increase in ferrihydrite-like nanoparticles lead to a higher availability of surface reactive sites and subsequently to an increase in the sorption capacity of the Fe-OM aggregates for pollutants that exhibit a greater affinity for minerals than for organics. [ABSTRACT FROM AUTHOR]

Gold nanoclusters (Au NCs) are attractive luminescent nanoprobes for biomedical applications. In vivo biosensing and bioimaging requires the delivery of the Au NCs into subcellular compartments. In this view, we explore here the possible encapsulation of ultra-small-sized red and blue emitting Au NCs into liposomes of various sizes and chemical compositions. Different methods were investigated to prepare vesicles containing Au NCs in their lumen. The efficiency of the process was correlated to the structural and morphological aspect of the Au NCs' encapsulating vesicles thanks to complementary analyses by SAXS, cryo-TEM, and confocal microscopy techniques. Cell-like-sized vesicles (GUVs) encapsulating red or blue Au NCs were successfully obtained by an innovative method using emulsion phase transfer. Furthermore, exosome-like-sized vesicles (LUVs) containing Au NCs were obtained with an encapsulation yield of 40%, as estimated from ICP-MS. [ABSTRACT FROM AUTHOR]

The oocyte microenvironment constituted by the follicular fluid (FF) is a key for the optimal development of female gametes. Its composition reflects the physiological state of the ovarian follicle. The particularity of FF is to contain a huge diversity of extracellular vesicles specific to women, in the same way as seminal plasma in men. Here, we described and compared morphological aspects of broad subcategories of human FF-related Extracellular Vesicles (EVs). EVs participate in physiological and pathological processes and have potential applications in diagnostics or therapeutics. EVs isolated from FF are involved in different biological functions related to follicular growth, oocyte maturation, and embryo development. However, knowledge on the morphology of FF-derived EVs is limited, mainly due to their sub-micrometer size and to intrinsic limitations in methods applied for their characterization. The aim of this study was to provide a comprehensive morphological description of EVs from FF of healthy subjects and quantification. EVs separation was realized by centrifugation, with comparison of the EV yield obtained from differential centrifugation and one-step ultracentrifugation. Cryo-Transmission Electron Microscopy was used to reveal the morphology, size, and phenotype of EVs. Dynamic Light Scattering (DLS) and Nanoparticle Tracking Analysis (NTA) were used to quantify and analyze the size distribution for each centrifugation step. We performed a comprehensive inventory of human follicular fluid EVs. We show that human FF contains a huge diversity of EVs. This study brings novel insights on EVs from normal FF and provides a reference for further studies of EVs in ovarian diseases. [ABSTRACT FROM AUTHOR]

Glioblastoma is a devastating tumor of the central nervous system characterized by a poor survival and an extremely dark prognosis, making its diagnosis, treatment and monitoring highly challenging. Numerous studies have highlighted extracellular vesicles (EVs) as key players of tumor growth, invasiveness and resistance, as they carry and disseminate oncogenic material in the local tumor microenvironment and at distance. However, whether their quality and quantity reflect individual health status and changes in homeostasis is still not fully elucidated. Here, we separated EVs from plasma collected at different time points alongside with the clinical management of GBM patients. Our findings confirm that plasmatic EVs could be separated and characterized with standardized protocols, thereby ensuring the reliability of measuring vesiclemia, i.e. extracellular vesicle concentration in plasma. This unveils that vesiclemia is a dynamic parameter, which could be reflecting tumor burden and/or response to treatments. Further label-free liquid chromatography tandem mass spectrometry unmasks the von Willebrand Factor (VWF) as a selective protein hallmark for GBM-patient EVs. Our data thus support the notion that EVs from GBM patients showed differential protein cargos that can be further surveyed in circulating EVs, together with vesiclemia. [ABSTRACT FROM AUTHOR]

Purpose: Current preclinical therapeutic strategies involving nanomedicine require increasingly sophisticated nanosystems and the characterization of the complexity of such nanoassemblies is becoming a major issue. Accurate characterization is often the factor that can accelerate the translational approaches of nanomedicines and their pharmaceutical development to reach the clinic faster. We conducted a case study involving the adsorption of the NFL-TBS.40–63 (NFL) peptide (derived from neurofilaments) to the surface of lipid nanocapsules (LNCs) (a combined nanosystem used to target glioblastoma cells) to develop an analytical approach combining the separation and the quantification in a single step, leading to the characterization of the proportion of free peptide and thus the proportion of peptide adsorbed to the lipid nanocapsule surface. Methods: LNC suspensions, NFL peptide solution and LNC/NFL peptide mixtures were characterized using a Size-Exclusion Chromatography method (with a chromatographic apparatus). In addition, this method was compared to centrifugal-filtration devices, currently used in literature for this case study. Results: Combining the steps for separation and characterization in one single sequence improved the accuracy and robustness of the data and led to reproducible results. Moreover the data deviation observed for the centrifugal-filtration devices demonstrated the limits for this increasingly used characterization approach, explained by the poor separation quality and highlighting the importance for the method optimization. The high potential of the technique was shown, proving that H-bond and/or electrostatic interactions mediate adsorption of the NFL peptide to the surface of LNCs. Conclusions: Used only as a characterization tool, the process using chromatographic apparatus is less time and solvent consuming than classical Size-Exclusion Chromatography columns only used for separation. It could be a promising tool for the scientific community for characterizing the interactions of other combinations of nanosystems and active biological agents. [ABSTRACT FROM AUTHOR]

A growing body of evidences indicate the major role of extracellular vesicles (EVs) as players of cell communication in the pathogenesis of liver diseases. EVs are membrane-enclosed vesicles released by cells into the extracellular environment. Oxidative stress is also a key component of liver disease pathogenesis, but no role for hepatocyte-derived EVs has yet been described in the development of this process. Recently, some polycyclic aromatic hydrocarbons (PAHs), widespread environmental contaminants, were demonstrated to induce EV release from hepatocytes. They are also well-known to trigger oxidative stress leading to cell death. Therefore, the aim of this work was to investigate the involvement of EVs derived from PAHs-treated hepatocytes (PAH-EVs) in possible oxidative damages of healthy recipient hepatocytes, using both WIF-B9 and primary rat hepatocytes. We first showed that the release of EVs from PAHs -treated hepatocytes depended on oxidative stress. PAH-EVs were enriched in proteins related to oxidative stress such as NADPH oxidase and ferritin. They were also demonstrated to contain more iron. PAH-EVs could then induce oxidative stress in recipient hepatocytes, thereby leading to apoptosis. Mitochondria and lysosomes of recipient hepatocytes exhibited significant structural alterations. All those damages were dependent on internalization of EVs that reached lysosomes with their cargoes. Lysosomes thus appeared as critical organelles for EVs to induce apoptosis. In addition, pro-oxidant components of PAH-EVs, e.g. NADPH oxidase and iron, were revealed to be necessary for this cell death. Image 1 • Polycyclic aromatic hydrocarbons (PAHs) trigger extracellular vesicle (EV) release. • EV release by PAH-treated hepatocytes (PAH-EVs) is dependent on oxidative stress. • PAH-EVs are enriched in components related to oxidative stress, notably iron. • PAH-EVs are endocytosed in recipient healthy hepatocytes and induce oxidative stress. • Apoptosis of recipient hepatocytes involves pro-oxidant components of PAH-EVs. [ABSTRACT FROM AUTHOR]

• Egg sphingosomes are facetted in absence of lutein and exhibit ondulations. • Lutein crystals melt above human body temperature. • Egg sphingomyelin bilayers solubilise lutein molecules below 80 mg lutein / g ESM. • Lutein molecules are intercalated vertically in the bilayers. • Sphingosomes will contribute in the development of lutein-fortified functionnal foods. Lutein is a xanthophyll carotenoid provided exclusively by the diet, that has protective functions and beneficial effects on human health. Supplementation in lutein is necessary to reach the recommended daily dietary intake. However, the introduction of lutein into foods and beverages is a real challenge since this lipophilic nutrient has a poor aqueous solubility and a low bioavailability. In this study, we investigated the capacity of egg-sphingomyelin (ESM) vesicles called sphingosomes to solubilise lutein into the bilayers. The thermal and structural properties of ESM bilayers were examined in presence of various amounts of lutein by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the structures of sphingosomes and lutein crystals were observed by microscopic techniques. ESM bilayers were in the fluid L α phase above the phase transition temperature T m = 39.6 °C and in the lamellar ripple P β′ phase below T m where ESM sphingosomes exhibited ondulations and were facetted. Lutein molecules were successfully incorporated into the ESM bilayers where they induced a structural disorganisation. For ESM/lutein 90/10 %mol (91.8/8.2 %wt; 89 mg lutein / g ESM), lutein partitioning occured with the formation of lutein crystals in the aqueous phase together with lutein-loaded ESM vesicles. This study highlighted the capacity of new lipid carriers such as egg-sphingosomes to solubilise lutein and opens perspectives for the formulation of effective lutein-fortified functionnal foods and beverages providing health benefits. [ABSTRACT FROM AUTHOR]