Physicochemical Properties Of Nanoemulsions Research Articles

Development, characterization, and in vitro biocompatibility of evening primrose oil nanoemulsions using ultrasonic nano-emulsification technology

BackgroundIn this study, evening primrose oil (EPO), recognized for its bioactivity and safety, played a pivotal role as a primary component in the production of nanoemulsions (NEs) through a combination of homogenization and ultrasonic nano-emulsification technology. The significance of EPO NEs lies in their potential impact on various aspects of health and well-being. The research aimed to explore the physicochemical properties, encapsulation efficiency, and in vitro biocompatibility of the resulting EPO NEs by employing three distinct surfactants: dioctadecyl dimethylammonium bromide (D+), dihexadecyl phosphate (D−), and saponin (Sn) for stabilization. MethodsResponse surface methodology (RSM) was used to optimize the preparation parameters of the NEs. The physicochemical properties of NEs were assessed using various techniques, including dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, fluorescence polarization spectroscopy, and viscometer measurements. The encapsulation efficiency of the NEs was evaluated through the use of quercetin. Furthermore, the in vitro biocompatibility of the NEs was assessed via a cell viability assay. FindingsRSM effectively determined the optimal ultrasonication operation parameters, including time and amplitude, to achieve EPO NE with the desired size and distribution. The thermal phase change and intra-particle fluidity of NEs decreased as the oil/surfactant ratio increased and varied with the type of surfactant used. Furthermore, EPO NE exhibited nearly Newtonian fluid characteristics. Most importantly, all NEs demonstrated excellent in vitro biocompatibility and high encapsulation efficiency. In conclusion, the high potential of EPO NEs underscores their pivotal role in advancing drug delivery systems.

Preparation, stability, and in vitro transport of soybean protein-based diosgenin nanoemulsions

Soybean protein isolate (SPI)-stabilized nanoemulsions (NEs) were formulated to encapsulate diosgenin (DIO) to enhance its water solubility and bioavailability. The influence of DIO concentrations on NEs’ properties was investigated, and their environmental stability and cell permeability were also assessed. Results demonstrated that DIO significantly affected all the physicochemical properties of NEs. NEs with 1.0 mg/mL of DIO exhibited smaller droplet size (209 nm), lower polydispersity index (0.17), and higher stability coefficient (95.8 %). Furthermore, DIO-SPI NEs displayed better stability under appropriate pH (<4 or > 5), NaCl concentrations (≤0.3 M), temperatures (≤60 °C), and freeze–thaw cycles (≤2), as well as storage at 4 °C. Moreover, encapsulating DIO in NEs reduced its toxicity towards cells and enhanced its transport efficiency, which reached 3.16 ∼ 4.87 × 10−6. These findings highlight the potential of SPI-based NEs as a promising carrier for the efficient delivery of DIO.

Novel acaricidal and growth-regulating activity of Aloe vera and Rheum rhabarbarum extracts and their oil/water nanoemulsions against the camel tick, Hyalomma dromedarii

Hyalomma dromedarii is an important tick species infesting livestock. This work evaluated the novel adulticidal, insect growth-regulating, and enzymatic efficacy of ethanol plant extracts of Aloe vera and Rheum rhabarbarum and their nanoemulsions against males and engorged females of the camel tick, H. dromedarii. The physicochemical properties of nanoemulsions were evaluated. The High-Performance Liquid Chromatography (HPLC) analyses indicated that the extracts contained polyphenols and flavonoids, which could enhance their acaricidal effect. Dynamic light scattering (DLS) of the nanoemulsions of A. vera and R. rhabarbarum were 196.7 and 291 nm, whereas their zeta potentials were − 29.1 and − 53.1 mV, respectively. Transmission electron microscope (TEM) indicated that nanoemulsions showed a regular spherical shape (less than 100 nm). Fifteen days post-treatment (PT) with 25%, the mortality% of A. vera and R. rhabarbarum were 88.5 and 96.2%, respectively. Five days PT, the median lethal concentration values of A. vera, R. rhabarbarum, and their nanoemulsions were 7.8, 7.1, 2.8, and 1.02%, respectively, and their toxicity indices were 91.02, 100, 36.4, and 100%, respectively. Their median lethal time values PT with 3.5% were 6.09, 5.09, 1.75, and 1.34 days, respectively. Nanoemulsions enhanced the efficacy of the crude extract 1–7 folds, 5 days PT, and accelerated their speed of killing ticks 2–4 times. The total protein and carbohydrates, Acetylcholinesterase, Alpha esterase, and Amylase were affected PT. The reproductive potential of engorged females was adversely impacted. In conclusion, the novel A. vera and R. rhabarbarum extracts were promising acaricides, and their nanoformulations enhanced their efficacies.

The Effect of Temperature and Incubation Period on the Size and Polydispersity Index of the Nano-Emulsion Containing Essential Oil from &lt;i&gt;Cinnamomum zeylanicum &lt;/i&gt;

Nanotechnology permits broad advances in agricultural research, such as disease prevention and treatment in plants using various approaches including nano-fungicide. Nano-fungicide has been able to draw much attention due to its higher efficacy even at very low doses because nano-sized particles could be more chemically reactive and bioactive than larger particles. Nano-fungicide is defined as a nanomaterial containing an active ingredient (essential oil etc.) with fungicide action and is incorporated into nano-emulsion. Nano-emulsion is obtained when the size of an emulsion droplet reaches approximately 20-500 nm. The physicochemical properties of nano-emulsions are interesting for practical applications especially in agriculture because of their small droplet size and long-term stability. Previously, a nano-fungicide formulation was developed using the nano-emulsion composition of the detergent Span 80 and Tween 80 and the essential oil extracted from the plant leaves of Cinnamomum zeylanicum (cinnamon) was successful to control the growth of Aspergillus flavus in storage grain corn. In this study, we investigated the effect of temperature at 4°C, 30°C and 60°C on the size and polydispersity index (PDI) of the nano-emulsion droplet at day 1, 30 and 60 of storage. The results of the nano-emulsion droplet size were significantly increased at 60°C after 30 and 60 days of storage and stable from 4 to 30°C even at 60 days of storage. This study provides a strategy to evaluates the effect of environmental factors on the quality of the formulated product, which is utilized for the prediction of its shelf life and determine proper storage conditions. Therefore, the optimized nano-emulsion formulation was characterized by droplet size and PDI for 2 months.

WETTABILITY AND FRICCOHESITY OF EMULSIONS: COVID-19 KILLING ROBUST SCIENCE - A REVIEW

COVID-19 is currently a big threat to global health. However, no specific antiviral agent is available for its treatment yet. As per the vaccine is considered, there is a long way to go. So, the best treatment in present scenario are precaution and protection both. Covid-19 is menacing the whole of humanity and so the whole of humanity must fight back. The important tools used to fight against covid-19 are the two important properties of nanoemulsions -wettability and friccohesity. Nanoemulsions are considered as the colloidal monodispersion systems which are supposed to be thermodynamically and kinetically stable and composed of two or more immiscible liquid and emulsifying agents (surfactants and cosurfactant) mixed to form a single phase. Stable nanoemulsions are known to be investigated as efficient drug delivery systems. This review paper is formulated to provide understanding and consolidated information regarding different physicochemical properties of nanoemulsions like wettability, friccohesity and surface tension as a tool to fight against COVID19. This review paper also comprises a comparative study of various types of emulsions like soap, inorganic, and organic sanitizers role in fighting COVID19.

Preservation of mushrooms (Agaricus bisporus) by an alginate-based-coating containing a cinnamaldehyde essential oil nanoemulsion

The physicochemical properties of nanoemulsions containing cinnamaldehyde (CIN) at different concentrations (0.025 %, 0.05 %, and 0.1 %, v/v) and Tween 80 (0.05 %, v/v) were investigated. Additionally, the effect of alginate-based coatings [1.0 %, (w/v), glycerol 0.125 (mL/g alginate)] incorporated with CIN nanoemulsions on the quality attributes and shelf life of button mushrooms (Agaricus bisporus) during 16 days of storage at 4 °C was evaluated. Nanoemulsions with a CIN:Tween 80 ratio of 1:1 reached the smallest droplet size (183 nm) and were the most stable. The quality of the mushrooms was remarkably improved by the incorporation of CIN nanoemulsions into coatings, decreasing the respiration rate, weight loss, PPO activity, and Pseudomonas counts and increasing retention of firmness, color, total polyphenols, and antioxidant capacity of mushrooms compared to those in the control group. These results can be associated with the small droplet size of CIN and its relatively uniform dispersion in the coating. Nanoemulsified coatings represent a promising alternative to maintain the quality of mushrooms and extend their shelf life.

Nanoemulsion flooding for enhanced oil recovery: Theoretical concepts, numerical simulation and history match

In current scenario of depleting oil reserves, chemical flooding is a vital enhanced oil recovery (EOR) technique. Present study discusses laboratory flooding experiments of surfactant/nanoparticle nanoemulsions on sand-pack system, with bulk approach to model and simulate the flooding strategies portraying the potential of nanoemulsion assisted EOR. Physicochemical properties of nanoemulsions were characterized in terms of droplets size, interfacial tension, wetting behavior, viscosity improvement and crude oil displacement. A numerical methodological simulation is performed on porous media through CMG-STARS simulator. Cartesian single porosity model equipped with well pattern, injection fluid flow-rate and rock-fluid properties was developed via simulation tool during compositional investigation. Tuning of relative permeability values to successfully fit with cumulative oil production and water cut was extremely challenging role during model development. Oil saturation profiles and relative permeability curves displayed the alteration in wetting behavior of sand-pack system to strongly water-wet from oil/intermediate-wet condition. 23–28% tertiary recoveries were achieved, contingent to composition of surfactant/nanoparticle in injected nanoemulsion. History match (HM) of production data via CMOST for experimental and simulation outcomes exhibited a good match with global HM error < 6%. Numerical simulation investigation facilitates a holistic approach to predict the performance and practicability of nanoemulsions as chemical EOR fluid.

Effect of environmental stresses on physicochemical properties of ALA oil-in-water nanoemulsion system prepared by emulsion phase inversion

To solve the stability and oxidation issues of alpha-linolenic acid (ALA), this study focused on developing ALA nanoemulsion system (ALA-NE, oil-in-water) and evaluating the effect of environmental conditions on physical stability and the effect of antioxidants on oxidative stability. The physicochemical properties of nanoemulsions were measured at different conditions, including particle diameter, zeta potential, retention rate and peroxidation value (POV). The particle diameter increased significantly and the retention rate decreased after 25 days storage under the conditions of high temperature and metal ions. However, the influence of ionic strength, pH and light was insignificant. As an antioxidant, Vitamin E was more effective at retarding lipid oxidation of nanoemulsions than that of vitamin C. These results provided reference information in preparing effective and stable ALA-NE systems and enlarging the application fields.

Topical delivery of antifungal Brazilian red propolis benzophenones-rich extract by means of cationic lipid nanoemulsions optimized by means of Box-Behnken Design

Recent studies have demonstrated the antifungal activity of a benzophenones-rich extract (BZP) from Brazilian red propolis against non-albicans Candida strains. This study aimed to optimize the incorporation of BZP into nanoemulsions intended for the treatment of mucocutaneous fungal infections. Formulations were optimized by means of a Box-Behnken Design, which allowed evaluating simultaneously the influence of the phospholipid egg-lecithin, the cationic lipid DOTAP and BZP concentrations on the physicochemical properties of nanoemulsions, as well as on the BZP association efficiency. By using the Mini Tab® software, the optimal formulation selected, based on the smallest droplet size and highest zeta potential and association efficiency, exhibited a mean average size of 140.56 ± 5.22 nm, zeta potential of +60.72 ± 3.07 and association efficiency of 99.55 ± 1.09%. Franz-type diffusion cells were used to evaluate BZP distribution through porcine skin and mucosa. BZP were found in both mucosa and skin layers (mainly in the dermis). A higher amount of BZP (up to 3-fold) was detected in impaired skin and mucosa demonstrating the effect of the integrity of the tissue on BZP distribution, as suggested by confocal fluorescence microscopy images. BZP were detected in the receptor fluid only when esophageal mucosa was impaired. The antifungal activity of the formulations was investigated against non-albicans Candida species – C. krusei, C. glabrata, C. tropicalis and C. parapsilosis. MIC values varied from 0.654 to 2.617 μg/mL, with cell damage higher than 78% as verified by MTT assay. Such a result suggests that the optimized formulation has promising potential to be used topically for the treatment of mucocutaneous fungal infections.

Eco-friendly pesticide based on peppermint oil nanoemulsion: preparation, physicochemical properties, and its aphicidal activity against cotton aphid.

Using organic insecticides including plant oils, it is possible to design a new perspective for the control of insect pests. In this research, nanoemulsion formulations of Mentha piperita, wild-type essential oil (EO) were prepared utilizing high-energy ultrasonication process. Physicochemical properties of nanoemulsions were precisely studied by measurement various parameters including pH, viscosity, conductivity, and zeta potential. Experimental design by the aid of response surface methodology (RSM) was used to highlight the physicochemical roles of EO percentage (1% to 5% (v/v)) and surfactant concentration (3% to 15% (v/v)) for achieving minimum droplet diameter with high physical stability. The nanoemulsion formulations were then characterized using dynamic light scattering, transmission electron microscopy, and optical clarity. Afterward, an appropriate model between the variable factors (EO percentage and surfactant concentration) and the response (hydrodynamic particle size) was statistically developed. Under the optimum conditions, nanoemulsion with hydrodynamic particle size less than 10nm with high physical stability is obtainable. Bioassay experiments were carried out to elucidate the effects of nanoemulsion on the cotton aphid. Synthesized nanoemulsion formulations showed relatively high contact toxicity (average value of LC50 was about 3879.5 ± 16.2μl a.i./L) against the pest. On the basis of the obtained results, prepared nanoemulsion using M. piperita is potentially applicable as organic insecticides against cotton aphid. Graphical abstract.

Mangiferin nanoemulsions in treatment of inflammatory disorders and skin regeneration

In this paper mangiferin nanoemulsions were developed using hyaluronic acid of different molecular weight, in absence or presence of Transcutol-P. An extensive study was carried out on the physico-chemical properties of nanoemulsions. Nanosizer and transmission electron microscopy showed oil droplets average size 296 nm with monodisperses distribution (PI ≤ 0.30). The zeta potential was highly negative (−30 mV). FTIR analysis confirms the existence of physical interactions among compounds. Rheological measurements allowed to conclude that all formulations present a pseudoplastic behavior (s ∼ 0.4) in presence of the biopolymer. Moreover, mangiferin release depends on the molecular weight of the polymer. Permeability assays on pig epidermis showed that nanoemulsions with low molecular weight hyaluronic acid improve the permeation, being this effect more pronounced in nanoemulsions with Transcutol-P. Administration of mangiferin nanoemulsions on TPA-inflamed skin mice model provided an attenuation of oedema and leucocyte infiltration. Macroscopic appearance of mice skin lesions has a good correlation with the histological study. The topical application of these formulations shows an appropriate anti-inflammatory effect.

Fabrication of β-conglycinin-stabilized nanoemulsions via ultrasound process and influence of SDS and PEG 10000 co-emulsifiers on the physicochemical properties of nanoemulsions

Nanoemulsions stabilized by β-conglycinin (7S), β-conglycinin/sodium dodecyl sulfate (SDS) and β-conglycinin/polyethylene glycol 10000 (PEG 10000) were produced via ultrasound process. All the nanoemulsions showed the desired mean particle size and narrow size distribution. The effects of pH, ionic strength and temperature on the properties of the nanoemulsions were investigated, and the long-term stability of the fabricated nanoemulsions was also monitored during storage at 4 °C. The nanoemulsions prepared by 7S exhibited a good stability over various pH (<4 or >5), ionic strength (0–500 mM NaCl), thermal treatment (80 °C) and storage time (0–45 days). The stability of 7S nanoemulsions was enhanced by adding SDS, whereas reduced by adding PEG 10000, which could be attributed to the higher zeta-potential in the present of SDS leading to stronger electrostatic repulsion against droplet flocculation, whereas opposite was observed for the addition of PEG 10000. Therefore, this study provided important evidences for the fabrication of nanoemulsions using protein/surfactant complexes as the emulsion stabilizer via ultrasound process.

Effect of sodium alginate incorporation procedure on the physicochemical properties of nanoemulsions

The aim of this work was to evaluate the effect of sodium alginate incorporation procedure on the physicochemical properties of nanoemulsions formed by microfluidization. Emulsions prepared consisted of corn oil and Tween 20 as dispersed phase and sodium alginate solution as continuous phase. In order to obtain nanoemulsion A (NA), both phases were microfluidized together. On the other hand, coarse emulsion without sodium alginate was microfluidized and mixed with a microfluidized (MA) or non-microfluidized (N-MA) sodium alginate solution leading to nanoemulsions B(MA) and B(N-MA), respectively. NA exhibited the smallest particle size (261 nm) and monomodal distributions with a polydispersity index of 0.25. The ζ-potential, viscosity and WI of NA were −37 mV, 22.7 mPa s and 57.28, respectively. Spectroscopic, chromatographic and electron microscopic techniques were used to evaluate changes in microfluidized alginate molecules when they were within emulsions. After microfluidization, alginates suffered depolymerization and further rearrangement, changing the disposition of polymer chains around oil droplets and nanoemulsions characteristics. Thus, these results evidence the significant impact of sodium alginate incorporation procedure on the physicochemical properties of nanoemulsions and how it can affect to the stability of the resulting systems which are going to be used as functional ingredients in food matrices.

Elucidation of the mechanisms of action of Bacteriophage K/nano-emulsion formulations against S. aureus via measurement of particle size and zeta potential

In earlier work we have demonstrated the effect that nano-emulsions have on bacterial growth, and most importantly the enhanced bacteriophage infectivity against Staphylococcus aureus in planktonic culture when phage are carried in nano-emulsions. However, the mechanisms of enhancement of the bacteriophage killing effect are not specifically understood. This work focuses on the investigation of the possible interactions between emulsion droplets and bacterial cells, between emulsion droplets and bacteriophages, and finally interactions between all three components: nano-emulsion droplets, bacteria, and bacteriophages. The first approach consists of simple calculations to determine the spatial distribution of the components, based on measurements of particle size. It was found that nano-emulsion droplets are much more numerous than bacteria or bacteriophage, and due to their size and surface area they must be covering the surface of both cells and bacteriophage particles. Stabilisation of bacteriophages due to electrostatic forces and interaction with nano-emulsion droplets is suspected, since bacteriophages may be protected against inactivation due to ‘charge shielding’. Zeta potential was measured for the individual components in the system, and for all of them combined. It was concluded that the presence of nano-emulsions could be reducing electrostatic repulsion between bacterial cells and bacteriophage, both of which are very negatively ‘charged’. Moreover, nano-emulsions lead to more favourable interaction between bacteriophages and bacteria, enhancing the anti-microbial or killing effect. These findings are relevant since the physicochemical properties of nano-emulsions (i.e. particle size distribution and zeta potential) are key in determining the efficacy of the formulation against infection in the context of responsive burn wound dressings—which is the main target for this work.Data Access: All data created during this research are openly available from the University of Bath data archive at http://doi.org/10.15125/BATH-00166.

Antioxidant Effect of Nanoemulsions Containing Extract of Achyrocline satureioides (Lam) D.C.-Asteraceae.

Ethanolic extracts of Achyrocline satureioides have pronounced antioxidant activity mainly due to the presence of the flavonoid quercetin. However, direct topical application of the extract is not possible due to the presence of high amounts of ethanol. In this sense, nanoemulsions arise as an alternative for topical formulation associating molecules with limited aqueous solubility. This article describes the development of topical nanoemulsions containing either A. satureioides extract or one of its most abundant flavonoid, quercetin. Nanoemulsions composed of octyldodecanol, egg lecithin, water and extract (NEE), or quercetin (NEQ) were prepared by spontaneous emulsification. This process led to monodisperse nanoemulsions presenting a mean droplet size of approximately 200-300nm, negative zeta potential, and high association efficiency. A study of quercetin skin retention using porcine skin which was performed using a Franz diffusion cell revealed a higher accumulation of quercetin in skin for NEE when compared to NEQ. Finally, the antioxidant activity of formulations was measured by thiobarbituric acid-reactive species and the APPH model. A lower lipoperoxidation for the extract in respect to quercetin solution was observed. However, no difference between NEQ and NEE lipoperoxidation could be seen. The protection against lipoperoxidation by the formulations was also measured in the skin, where lower formation of reactive species was observed after treatment with NEE. In conclusion, this study shows the formulation effect on the physicochemical properties of nanoemulsions as well as on the skin retention and antioxidant activity of quercetin.

Whey-protein-stabilized nanoemulsions as a potential delivery system for water-insoluble curcumin

Nanoemulsions stabilized by whey protein isolate were successfully produced. The effects of the protein concentration, homogenization pressure, oil-to-water ratio and ι-carrageenan on the properties of the nanoemulsions were investigated. The nanoemulsions prepared only by whey protein isolate exhibited a notably good stability over various ionic strengths and thermal treatments and upon storage. ι-Carrageenan added in various concentrations has scarcely any significant effect on the physicochemical properties of nanoemulsions. The results suggested that it may not be necessary to use a polysaccharide as a second layer for the preparation of nanoemulsions when a relatively high protein concentration was used as the emulsifier to stabilize the nanoemulsions.