•Oregano and clove nanoemulsions were used as antifungals in media and dressings.•The effect of nanoemulsions on the sensory profile of dressings was tested.•Efficacy of essential oil nanoemulsions ...against Z. bailii was demonstrated.•Addition of nanoemulsions to salad dressings prolonged their shelf life.•Sensory panellists accepted the salad dressing with oregano nanoemulsion.
This work aimed to evaluate the in vitro effect of encapsulated oregano and clove essential oils on oil-in-water nanoemulsions against Zygosaccharomyces bailii. The antifungal efficacy of these nanoemulsions and their sensory acceptance were tested in salad dressings. Both essential oils were effective inhibitors against the target yeast, with minimal inhibitory and fungicidal concentrations of 1.75 mg/mL. In the in vitro assay done with the nanoemulsions, no yeast growth was observed for any tested essential oil concentration. In the salad dressings, all the formulations were able to reduce Z. bailii growth compared to the control, and only those samples with 1.95 mg/g of essential oil were capable of inhibiting yeast development after 4 inoculation days. The sensory acceptance of the dressing containing the nanoemulsions was similar to the control dressing in appearance, consistency and colour terms. These results evidence the antifungal activity of oregano and clove nanoemulsions against Z. bailii.
Rationale: Immune checkpoint (ICP) blockade therapy combined with chemotherapy is a promising treatment strategy for tumors. Chemotherapeutic agents usually function inside the tumor cells, while ICP ...inhibitors are efficacious out of the tumor cells. It is desirable to effectively co-deliver an ICP inhibitor and a chemotherapy agent to different sites of a tumor. We have designed an effective drug delivery system to accomplish both objectives. Methods: We designed a Pickering nanoemulsion (PNE) using multi-sensitive nanogels with pH-responsive, hydrophilicity-hydrophobicity switch, and redox-responding properties as an oil/water interfacial stabilizer. The D/HY@PNE was employed for specified spatial delivery of the chemotherapy agent doxorubicin (DOX) and ICP inhibitor HY19991 (HY). We systematically investigated the pH-responsive disassembly of PNE, the release of DOX and HY from D/HY@PNE in the tumor microenvironment, enhanced tumor penetration of DOX, immunogenic cell death (ICD), antitumor efficacy, and the immune response induced by D/HY@PNE in vitro and in vivo. Results: D/HY@PNE disassembled to release the ICP inhibitor HY and DOX-loaded nanogels due to the hydrophilicity-hydrophobicity reversal of nanogels in the acidic tumor microenvironment. Quantitative analysis indicates that D/HY@PNE presents enhanced tumor penetration behavior and effectively induces ICD. The strong immune response induced by D/HY@PNE was due to the efficient synergetic combination of chemotherapy and immunotherapy and resulted in enhanced antitumor efficacy in 4T1 tumor-bearing mice. Conclusion: This novel strategy highlights the promising potential of a universal platform to co-deliver different therapeutic or diagnostic reagents with spatial regulation to improve the anti-tumor effect.
Palmyra (Borassus flabellifer Linn.) palm fruits are bright yellow and have a unique sweet scent. The ripe palm fruits are a rich source of carotenoids which are used as a non-toxic natural dye and ...have been recognized for their antioxidant benefits. This study aimed to explore the potential of palm fruit extract as a natural coloring agent. The ripe mesocarp of B. flabellifer was extracted using various organic solvents. The carotenoid content, polysaccharide composition, and antioxidant activity of the palm extracts were investigated. The ethanolic palm extract was selected for stability study in various conditions (pH, time, light, and temperature). Then, the extracted nanoemulsion loaded with B. flabellifer extract was formulated and evaluated. The ethanolic extract from the freeze-dried sample yielded high extractive content (42.9%) and showed the greatest antioxidant activity (IC50 2.4 mg/mL). The color intensity of the extract did not fade after exposure to a pH of more than 4. After the storage for 14 days, the color intensity significantly decreased. The light exposure did not influence the color intensity at 25°C. B. flabellifer ethanolic extracted nanoemulsions were successfully prepared by ultrasonication method with the oil to surfactant weight ratio of 1:9. The nanoemulsions loaded with ethanolic extract were stable. The nanoemulsion of the pulp extract could potentially be used as a natural dye.
Most of the traditional strategies used for facing the management of insect pest and diseases have started to fail due to different toxicological issues such as the resistance of target organism and ...the impact on environment and human health. This has made mandatory to seek new effective strategies, which minimize the risks and hazards without compromising the effectiveness of the products. The use of essential oils, their components and semiochemicals (pheromones and allelochemicals) has become a promising safe and eco-sustainable alternative for controlling insect pest and pathogens. However, the practical applications of this type of molecules remain rather limited because their high volatility, poor solubility in water and low chemical stability. Therefore, it is required to design strategies enabling their use without any alteration of their biological and chemical properties. Oil-in-water nano/microemulsions are currently considered as promising tools for taking advantage of the bioactivity of essential oils and their components against insects and other pathogens. Furthermore, these colloidal systems also allows the encapsulation and controlled release of semiochemicals, which enables their use in traps for monitoring, trapping or mating disruption of insects, and in push-pull strategies for their behavioral manipulation. This has been possible because the use of nano/microemulsions allows combining the protection provided by the hydrophobic environment created within the droplets with the enhanced dispersion of the molecules in an aqueous environment, which favors the handling of the bioactive molecules, and limits their degradation, without any detrimental effect over their biological activity. This review analyzes some of the most recent advances on the use of emulsion-like dispersions as a tool for controlling insect pest and pathogens. It is worth noting that even though the current physico-chemical knowledge about these systems is relatively poor, a deeper study of the physico-chemical aspects of nanoemulsions/microemulsions containing essential oils, their components or semiochemicals, may help for developing most effective formulations, enabling the generalization of their use.
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•Essential oils (EOs), their components (EOCs) or semiochemicals (SE) are allows controlling insect pests and pathogens.•Instability and volatility of EOs, EOCs or SEs require of strategies for taking advantage of their biological activity.•Micro-/nanoemulsions are good tools for design formulations with EOs, EOCs or SEs.•EOs, EOCs or SEs contained within emulsion-like systems commonly present higher biological activity that their free form.•Physico-chemical and operative parameter are essential in the characteristics of the micro−/nanoemulsions.
Nanotechnology, particularly nanoemulsions (NEs), have gained increasing interest from researchers throughout the years. The small-sized droplet with a high surface area makes NEs important in many ...industries. In this review article, the components, properties, formation, and applications are summarized. The advantages and disadvantages are also described in this article. The formation of the nanosized emulsion can be divided into two types: high and low energy methods. In high energy methods, high-pressure homogenization, microfluidization, and ultrasonic emulsification are described thoroughly. Spontaneous emulsification, phase inversion temperature (PIT), phase inversion composition (PIC), and the less known D-phase emulsification (DPE) methods are emphasized in low energy methods. The applications of NEs are described in three main areas which are food, cosmetics, and drug delivery.
•Pickering nanoemulsion formulation and characterization have been reviewed.•EOR mechanisms during Pickering nanoemulsion flooding have been analyzed.•The key operational factors and their impacts ...have been highlighted.•The key limitations and obstacles still faced by the process have been discussed.•Proposals for future research to address the unresolved challenges are included.
The key mechanisms in enhancing crude oil recovery include the reduction of interfacial tension (IFT) between the trapped crude oil and the injected flooding solution, the wettability alteration of the reservoir rocks, in-situ emulsification, pore plugging, mobility control, disjoining and capillary pressures, miscibility improvement, etc. Recently, Pickering nanoemulsions have emerged as attractive flooding fluids that can positively alter all the above mechanisms and, thus, provide an improved oil recovery relative to other tertiary methods. The nanoparticles (NPs) used to stabilize Pickering nanoemulsions must be carefully selected and engineered in order to impart the desired characteristics (e.g., stability, emulsion type, droplet size, zeta potential, etc.). Yet, the relationship between the efficacy of Pickering nanoemulsions in enhancing oil recovery and their characteristics is very complex and not fully understood. Additionally, the oil recovery enhancement mechanisms are quite complex and governed by several interrelated factors. Therefore, this article provides a state-of-the-art review of the formulations and applications of Pickering nanoemulsions for enhancing the recovery of crude oil, with a focus on the recovery mechanisms. Relevant recent studies on the topic have been analyzed and assessed in order to provide insights into the achieved progress and to highlight the remaining obstacles and challenges. Future research work to address the key obstacles and challenges has been proposed.
We report two highly fluorinated Cu-based imaging agents, CuL1 and CuL2, for detecting cellular hypoxia as nanoemulsion formulations. Both complexes retained their initial quenched 19F MR signals due ...to paramagnetic Cu2+; however, both complexes displayed a large signal increase when the complex was reduced. DLS studies showed that the CuL1 nanoemulsion (NECuL1) had a hydrodiameter of approximately 100 nm and that it was stable for four weeks post-preparation. Hypoxic cells incubated with NECuL1 showed that 40% of the Cu2+ taken up was reduced in low oxygen environments.
Nanoemulsions exhibit unique behavior due to their nanoscopic dimensions, including remarkable droplet stability, interactions, and rheology. These properties are significantly enhanced by nanoscopic ...droplet size, as well as the selection of surfactant and other molecular species in solution. Electrostatic and polymer-induced interdroplet interactions are particularly powerful tools for fine-tuning the interdroplet interactions, and have led to stimuli-responsive nanoemulsion systems that provide deep insight into their unique properties. As such, nanoemulsions have emerged as powerful model systems for studying a number of colloidal phenomena including suspension rheology, repulsive and attractive colloidal glasses, aggregation processes, colloidal gelation and phase instability, and associative network formation in polymer–colloid mixtures. This review summarizes recent advances in understanding the colloidal behavior of nanoemulsions, and provides a unifying framework for understanding the various complex states that emerge, as well as perspective on emerging challenges and opportunities that will advance the use of nanoemulsions in both fundamental colloid science and technological applications.
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•We review efforts to understand and control colloidal behavior of nanoemulsions.•Electrostatic and polymer-induced interdroplet interactions are discussed.•Repulsive interactions lead to jammed and compressed states at low volume fraction.•Attractive interactions lead to clustering, gelation, and colloidal phase separation.•Nanoemulsions are model fluids to study arrested states in colloidal dispersions.
P2X7R is a purinergic receptor with broad expression throughout the body, especially in immune system cells. P2X7R activation causes inflammatory mediators to release, including interleukin-1β ...(IL-1β), the processing and release of which are critically dependent on this ion channel activation. P2X7R's therapeutic potential augments the discovery of new antagonistic compounds. Thus, we investigated whether the
essential oil could block P2X7R activity. The essential oil (ESO) dose-dependently inhibited ATP-promoted PI uptake and IL-1β release with an IC
of 113.3 ± 3.7 ng/mL and 274 ± 91 ng/mL, respectively, and the essential oil nanoemulsion (ESON) improved the ESO inhibitory effect with an IC
of 81.4 ± 7.2 ng/mL and 62 ± 2 ng/mL, respectively. ESO and ESON reversed the carrageenan-activated peritonitis in mice, and ESON exhibited an efficacy higher than ESO. The majority substance from essential oil, β-caryophyllene, impaired the ATP-evoked PI uptake and IL-1β release with an IC
value of 26 ± 0.007 ng/mL and 97 ± 0.012 ng/mL, respectively. Additionally, β-caryophyllene reduced carrageenan-induced peritonitis, and the molecular modeling and computational simulation predicted the intermolecular interactions in the P2X7R situs. In silico, results indicated β-caryophyllene as a potent allosteric P2X7R antagonist, although this substance may present toxic effects for humans. These data confirm the nanoemulsion of essential oil from
as a promisor biotechnology strategy for impaired P2X7R functions and the inflammatory response.
Edible films including active ingredients can be used as an alternative to preserve food products. Essential oils (EOs) exhibit antimicrobial activity against pathogenic microorganisms but their low ...water solubility limits the application in foods. To improve water dispersion and protect EOs from degradation, nano-sized emulsions emerge as a viable alternative. Nanoemulsions containing EOs and polysaccharides could be used to form edible films with functional properties. This study was focused on the evaluation of physical, mechanical and antimicrobial properties of alginate-based edible films formed from nanoemulsions of EOs. Nanoemulsions containing thyme (TH-EO), lemongrass (LG-EO) or sage (SG-EO) oil as dispersed phase and sodium alginate solution as continuous phase were prepared. The average droplet size of nanoemulsions was reduced after the microfluidization treatment exhibiting multimodal size distributions. The ζ-potentials of nanoemulsions were between −41 mV and −70 mV depending on the type of EO used. The lowest whiteness index was found in SG-EO nanoemulsions, whereas those containing TH-EO showed the highest value. Films formed from SG-EO nanoemulsions exhibited higher transparency, water vapor resistance and flexibility than films formed from TH-EO or LG-EO. Edible films containing TH-EO were those with the strongest antimicrobial effect against inoculated Escherichia coli, achieving up to 4.71 Log reductions after 12 h. Results obtained in the present work evidence the suitability of using nanoemulsions with active ingredients for the formation of edible films, with different physical and functional properties.
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•Nanoemulsions with very small oil droplet size were produced by microfluidization.•Alginate-based edible films from nanoemulsions containing essential oils were formed.•Oil droplet size and droplet charge of nanoemulsions determined edible film properties.•Antimicrobial activity of films was governed by oil type rather than oil droplet size.
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