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Although rare, amoebic keratitis (AK) is a disease caused by Acanthamoeba spp. that can lead to blindness. The drugs currently available for its treatment are very toxic, which has ...motivated the investigation for more effective and safe therapeutic options. In this study, the in vitro activity of ß-caryophyllene (BCP) was exploited taking into account its action against other protozoans as well as its well-known healing and anti-inflammatory properties (aspects relevant for the AK pathogenesis). On the other hand, high volatilization and oxidation phenomena are found for this compound, which led to its incorporation into nanoemulsions (NEs). Two emulsifying agents were tested, resulting in monodisperse systems with reduced droplet size (<265 nm) and high surface charge (positive and negative for NEs prepared with cetrimonium bromide −CTAB and Phosal® 50+, respectively). NEs prepared with CTAB were shown to be more stable after long-term storage at 4 and 25 °C than those prepared with Phosal®. Pure BCP, at the highest concentration (500 µM), resulted in a level of inhibition of Acanthamoeba trophozoites equivalent to that of reference drug (chlorhexidine). This activity was even greater after oil nanoencapsulation. The reduced droplet size could improve the interaction of the oil with the microorganism, justifying this finding. Changes in surface charge did not impact the activity. Positively charged NEs improved the interaction and retention of BCP in the cornea and thus should be prioritized for further studies.
Our main goal was to encapsulate oleuropein within double nano-emulsions stabilized by pectin-whey protein concentrate (WPC) complexes and prepared by sonication. Five independent variables including ...surfactant (Span) content, WPC and pectin content, ratio of inner to outer phase, and pH were considered along with size of emulsion droplets, zeta potential, and encapsulation efficiency as the dependent variables. Optimum conditions were determined as, 8% WPC, 1.97% pectin, 8.74% Span, 1:4 ratio of inner to outer phase and pH = 6.1. After 28 days storage, double emulsions loaded with oleuropein (260, 520, 780 and 1040 μg/mL) released approximately 39.9, 40.2, 42.2 and 42.9% of their total content. The results of oleuropein release after 28 days determined by HPLC (40.4%) were consistent with those obtained spectrophotometrically (42.9%). To produce double emulsions with the highest load, samples with 1040 (μg/mL) oleuropein were produced according to the optimum conditions and a droplet size of 191 nm, zeta potential of −26.8 mV, and encapsulation efficiency of 91% was achieved. SEM results showed particles with smooth, relatively spherical, somewhat asymmetrical surfaces with a size range of 100–200 nm compatible with dynamic light scattering results.
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•Oleuropein was successfully encapsulated within double nano-emulsions.•WPC-pectin complex could successfully protect oleuropein.•Emulsion droplet size of double emulsions was in the range of 200 nm.•A controlled release of oleuropein during 28 days storage was well achievable.
The formation, stability, and performance of oil-in-water emulsions may be improved by using combinations of two or more different emulsifiers, rather than an individual type. This article provides a ...review of the physicochemical basis for the ability of mixed emulsifiers to enhance emulsion properties. Initially, an overview of the most important physicochemical properties of emulsifiers is given, and then the nature of emulsifier interactions in solution and at interfaces is discussed. The impact of using mixed emulsifiers on the formation and stability of emulsions is then reviewed. Finally, the impact of using mixed emulsifiers on the functional performance of emulsifiers is given, including gastrointestinal fate, oxidative stability, antimicrobial activity, and release characteristics. This information should facilitate the selection of combinations of emulsifiers that will have improved performance in emulsion-based products.
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•Mixed emulsifiers may give better or worse performance than single ones.•Mixtures may involve proteins, polysaccharides, phospholipids, surfactants etc.•Emulsifier type and levels impact emulsion formation and stability.•Mixed emulsifiers can be used to provide novel functional attributes.
BackgroundDuring COVID19 pandemic, a small molecule antiviral agent PAXLOVIDTM was authorised for emergency use. The main antiviral component is nirmatrelvir, a coronavirus MPRO inhibitor, but it was ...combined with ritonavir to achieve persistent cell exposure. Respiratory virus usually infects through the nose and intranasal treatment is an attractive option for prophylactic treatment but challenging. Therefore, alternate strategies to deliver and retain nirmatrelvir within a treated cell is of great importance.AimThe aim of this project is to investigate antiviral effects of nirmatrelvir in a novel nanoemulsion formulation on coronavirus infected human primary nasal epithelium.MethodSeasonal coronavirus (HCOV-229E) was inoculated to the apical surface of air liquid interface (ALI) cultured human primary nasal epithelium. Viral load in apical wash was determined by a 50% tissue culture infectious dose (TCID50) assay and RT-PCR. Cell integrity, a marker of cell damage by virus infection, was measured as a transmembrane electrical resistance (TEER). 50 µL of nirmatrelvir (0.1 µM) prepared in water or as a nanoemulsion was applied to apical surface of ALI nasal epithelium for 10 min, and virus inoculum (0.2 MOI) was then applied to apical surface on top of the treatment for 1 hr. Apical surface wash with media was collected after treatment, then 1, 2 and 3 days post virus inoculation.ResultsHCoV viral load was maximal at Day 1 post inoculation. Analysis of the area under the curve (AUC) of viral load for 3 days post inoculation revealed that nirmatrelvir in water, nanoemulsion alone, and nirmatrelvir in nanoemulsion showed 69.5%, 89.8% and 100% inhibition of viral load vs. control, respectively. RT-PCR AUC was also inhibited by 13.5%, 52.2% and 100%, respectively, suggesting nirmatrelvir and nanoemulsion component showed synergistic effects. The nirmatrelvir in nanoemulsion also protected from virus induced reduction of TEER. The nirmatrelvir in nanoemulsion was well tolerated and not cytotoxic.ConclusionNovel nanoemulsion formulation of nirmatrelvir was found to show better antiviral effects against COV infection in human primary nasal epithelium.Please refer to page A291 for declarations of interest related to this abstract.
Sun protection formulations have undergone significant advancements, incorporating soft nanostructures to enhance their efficacy, safety, and aesthetic appeal. Nanoemulsions, with their controlled ...droplet size and improved ultraviolet (UV) absorption, are utilized in sunscreen formulations, boosting their photoprotective effects. Microemulsions, offering enhanced dispersion and delivery, enable the incorporation of new active ingredients, improving stability and skin permeation. Pickering emulsions, stabilized by particles provide stable, eco-friendly alternatives. Nanostructured lipid carriers, facilitate efficient encapsulation and delivery of various compounds, enhancing both UV protection and skin penetration. Nanoparticles (NPs), demonstrate promising results in improving photostability, preventing skin penetration, and enhancing antioxidant properties of sunscreens. SunSpheresTM, advanced UV boosters, scatter UV radiation effectively when integrated into sunscreen formulations, significantly increasing their sun protection factor values. This review highlights the diverse applications of soft nanostructures in sun protection, emphasizing their crucial role in the evolution of sunscreens for optimal skin safety and protection against UV radiation.
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Addition of supplementary materials without loss of dimension in 3D printed products can be carried out by adopting coaxial extrusion. This study aimed to produce starch-xanthan gum gels filled with ...nanoemulsions for customized food production based on coaxial 3D printing. Nanomemulsion-filled gel (NFG) was prepared by dispersing curcumin nanoemulsion in a mixture of xanthan gum in various concentrations and potato starch. NFGs were inserted as core parts into 3D printed products through the internal nozzle of the coaxial system. Xanthan gum content of 5% or more in NFG inhibited gelation of the starch matrix, resulting in loss of dynamic viscoelasticity and 3D printing performance. The 3% xanthan gum incorporation showed the highest shear modulus value (1792.00 ± 104.50 Pa) and the best shape support ability. The physical properties of the NFG were evaluated using a confocal laser scanning microscope and a DPPH assay; the particle size decreased and antioxidant activity increased as the level of XG increased.
•Nanomemulsion-filled gel (NFG) based on xanthan-starch matrix was produced.•NFGs were inserted into 3D printed products through a co-axial system.•The rheology of NFG can be controlled by xanthan gum on specific percentages.•The antioxidant activity of NFG increased with increasing xanthan gum levels.
•Nanoemulsions are a novel form for ophthalmic drug delivery system.•Lipophilic drugs used to treat ocular diseases like glaucoma and dry eye syndrome.•Lipophilic drugs are incorporated in ...nanoemulsion for optimum bioavailability.•Review on development and characterization of the ophthalmic nanoemulsions.
Nanoemulsions formulated for the ocular drug delivery have a good scope in pharmaceutical products due to the transparency at enlarged droplet volume fraction, advanced rate of bioavailability and improved shelf life. They are a part of multiphase colloidal dispersion where a heterogeneous system has fine oil in water or water in oil dispersion in addition with the surfactant and co-surfactant containing droplets within the size range of 20–600 nm and showing a narrow size distribution. This review describes the preparation, characteristics, evaluation and application of nanoemulsions as a drug delivery tool for medication delivery in eyes. The review summarizes in-depth information on the development of ophthalmic nanoemulsions providing sustained release and prolonged therapeutic effect. Various methods comprising of high energy techniques and low energy techniques are discussed in detail. Finally, the techniques for characterization, in-vivo evaluation and applications are deliberated in short.
Nanotechnology monitors a leading agricultural controlling process, especially by its miniature dimension. Additionally, many potential benefits such as enhancement of food quality and safety, ...reduction of agricultural inputs, enrichment of absorbing nanoscale nutrients from the soil, etc. allow the application of nanotechnology to be resonant encumbrance. Agriculture, food, and natural resources are a part of those challenges like sustainability, susceptibility, human health, and healthy life. The ambition of nanomaterials in agriculture is to reduce the amount of spread chemicals, minimize nutrient losses in fertilization and increased yield through pest and nutrient management. Nanotechnology has the prospective to improve the agriculture and food industry with novel nanotools for the controlling of rapid disease diagnostic, enhancing the capacity of plants to absorb nutrients among others. The significant interests of using nanotechnology in agriculture includes specific applications like nanofertilizers and nanopesticides to trail products and nutrients levels to increase the productivity without decontamination of soils, waters, and protection against several insect pest and microbial diseases. Nanotechnology may act as sensors for monitoring soil quality of agricultural field and thus it maintain the health of agricultural plants. This review covers the current challenges of sustainability, food security and climate change that are exploring by the researchers in the area of nanotechnology in the improvement of agriculture.
Synopsis
In recent decades, considerable and continuous growth in consumer demand in the cosmetics field has spurred the development of sophisticated formulations, aiming at high performance, ...attractive appearance, sensorial benefit and safety. Yet despite increasing demand from consumers, the formulator faces certain restrictions regarding the optimum equilibrium between the active compound concentration and the formulation base taking into account the nature of the skin structure, mainly concerning to the ideal penetration of the active compound, due to the natural skin barrier. Emulsion is a mixture of two immiscible phases, and the interest in nanoscale emulsion has been growing considerably in recent decades due to its specific attributes such as high stability, attractive appearance and drug delivery properties; therefore, performance is expected to improve using a lipid‐based nanocarrier. Nanoemulsions are generated by different approaches: the so‐called high‐energy and low‐energy methods. The global overview of these mechanisms and different alternatives for each method are presented in this paper, along with their benefits and drawbacks. As a cosmetics formulation is reflected in product delivery to consumers, nanoemulsion development with prospects for large‐scale production is one of the key attributes in the method selection process. Thus, the aim of this review was to highlight the main high‐ and low‐energy methods applicable in cosmetics and dermatological product development, their specificities, recent research on these methods in the cosmetics and consideration for the process selection optimization. The specific process with regard to inorganic nanoparticles, polymer nanoparticles and nanocapsule formulation is not considered in this paper.
Résumé
Au cours des dernières décennies, la croissance considérable et continue de la demande des consommateurs dans le domaine des cosmétiques a stimulé le développement de formulations sophistiquées, visant à haute performance, de belle apparence, de l'avantage sensoriel et de la sécurité. Pourtant, malgré la demande croissante des consommateurs, le formulateur est confronté à certaines restrictions concernant l'équilibre optimal entre la concentration en substance active et la base de la formulation, en tenant compte de la nature de la structure de la peau, concernant principalement à la pénétration idéale de la substance active, en raison de la nature barrière de la peau. Une émulsion est un mélange de deux phases non miscibles, et l'intérêt en émulsion à l'échelle nanométrique a augmenté considérablement au cours des dernières décennies en raison de ses attributs spécifiques tels que grande stabilité, les propriétés d'apparence et de vectorisation d'actifs attrayantes; par conséquent, on peut attendre une amélioration des performances par l'utilisation d'un nanocarrier à base de lipides. Les nanoémulsions sont générées par différentes approches: les méthodes dites de haute énergie et de faible énergie. La vue d'ensemble de ces mécanismes et différentes alternatives pour chaque méthode sont présentés dans ce document, ainsi que leurs avantages et inconvénients. Le développement de nano‐émulsion avec des perspectives de production à grande échelle est l'un des attributs clés dans le processus de sélection de la méthode. Ainsi, le but de cet examen est de mettre en évidence les principales méthodes de haute et basse énergie applicables dans les cosmétiques et le développement de produits dermatologiques, leurs spécificités, des recherches récentes sur ces méthodes dans les cosmétiques, et de considération pour l'optimisation des processus de sélection. Le processus spécifique en ce qui concerne des nanoparticules inorganiques, des nanoparticules de polymère et de la formulation de nanocapsules n'est pas considéré dans le présent document.
High‐speed two‐photon microscopy can be used to analyze vascular dynamics in living animals and is essential for the understanding of brain diseases. Recent advances in fluorescent probes/optical ...systems have allowed successful imaging of the hippocampal vasculature in the deep brain of mice (1 mm from the brain surface) under low‐speed conditions (1–2 fps); however, using high‐speed techniques (>30 fps), observation of the deep‐brain vasculature is still challenging. Here, a new nanoemulsion that encapsulates thousands of red‐emissive pyrene dye molecules while maintaining their high two‐photon brightness 1.5 × 102 GM (GM = 10−50 cm4·s·photon−1·molecule−1) at 960 nm excitation and delivers a large amount of such pyrene dyes (65 nmol) into the blood vessels of mice is developed. Remarkably, the nanoprobe is found to exploit the inherent performance of a commonly used Ti:sapphire excitation laser and a sensitive gallium arsenide phosphide nondescanned fluorescence detector to the limit, enabling visualization of the brain vasculature under the cortex region of mice (up to 1.5 mm) under very low‐speed conditions. As a highlight, such a nanoprobe is successfully used to directly observe the blood flow in the hippocampal CA1 region (1.1 mm) through high‐speed resonant scanning (120 fps).
A novel dye‐loaded nanoemulsion is developed for high‐speed two‐photon microscopic imaging of the deep‐brain vasculature in mice. The nanoprobe delivers numerous bright pyrene dyes into the blood vessels of mice, fully exploiting the performance of a Ti:sapphire laser and a gallium arsenide phosphide detector. This approach allows the visualization of hippocampal blood flow in mice at above the video rate.
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