Phase Inversion Composition Method Research Articles

Engineering ternary systems as non-viral vehicles for transporting floxuridine oligomer

The objective of this study is to evaluate the potential applicability of a ternary drug delivery system, that incorporates chitosan (CHI) into poly(lactic-co-glycolic) acid PLGA nanoparticles (NPs) and Floxouridine (FdU) oligomers with varying lengths to be delivered in cancer cells. Two FdU oligomers containing five (FdU5) and ten (FdU10) residues were used. PLGA NPs were prepared from O/W nano-emulsion templates using the low energy emulsification phase inversion composition (PIC) method. Binary vectors comprised of FdU oligomer/CHI and ternary vectors based on FdU/CHI/PLGA NPs were prepared and fully characterized in terms of size, surface charge, and morphology. The resultant ternary vectors displayed spherical morphology and positive surface charge, with particle sizes in the nanometric range at appropriate FdU5/CHI/PLGA and FdU10/CHI/PLGA ratios. The presence of CHI and FdU10 oligomer in the ternary system significantly reduced the cellular viability leading to greater cytotoxicity values (ca. 60 %) when compared to an unbound FdU10 oligomer. The potential of nano-emulsions as a tool for preparing ternary drug delivery systems and improving the transportation of FdU oligomers into tumor cells is highlighted in this study.

Optimal conditions for nano-emulsified vegetable oil synthesis for the biostimulation of 1,1,2-trichloroethane and vinyl chloride contaminated groundwater in bioreactors

Contamination of groundwater with chlorinated aliphatic hydrocarbons (CAHs) has become increasingly widespread. Enhanced reductive dechlorination (ERD) by emulsified vegetable oil (EVO) is an environmentally friendly, low-carbon and sustainable technology that effectively eliminates the threat from CAHs. To improve the permeability and bioavailability of EVO in the low-permeability substratum, nano-emulsified vegetable oil (nanoEVO) can be synthesized using a modified phase inversion composition method (MPIC) by increasing the emulsification temperature that reduces the shear force required for the formation of nanodroplets and the interfacial tension between the mixed phase and water. The emulsification temperature of 60 °C, the water content of 40–70%, the droplet diameter (DD) of nanoEVO prepared by MPIC is ∼200 nm, and had good monodispersion (≤0.2). The high molecular weight and low solubility of vegetable oil, and similar size of droplet make nanoEVO remains homogeneous after storage for > one year. NanoEVO can effectively biostimulate indigenous bacteria in CAHs-contaminated groundwater to dechlorinate 1,1,2-trichloroethane (1,1,2-TCA) to ethene via vinyl chloride (VC). The maximum dihaloelimination rate of 1,1,2-TCA was ∼66.06 μM·Cl−·day−1 and the maximum hydrogenolysis rate of VC was ∼35.67 μM·Cl−·day−1. NanoEVO effectively increased the relative abundance of Dehalococcoides from <0.10 to 9.61%. The abundances of Dhc 16S rRNA gene and dehalogenase gene vcrA increased by 102 and 103, respectively. Biostimulation shaped the structure of microbial communities and promoted hydrolytic acidification and anaerobic fermentation. Moreover, the syntrophic VFA-oxidizing bacteria participated in secondary fermentation and were closely correlated with H2 consumption metabolism. By providing carbon sources and maintaining an anaerobic environment with stable pH and ORP, nanoEVO biostimulated the hydrolytic acidification led by fermentative bacteria, secondary fermentation with syntrophic VFA-oxidizing bacteria and reductive dechlorination carried out by dechlorinator, thus greatly increasing the CAH-dechlorinating ability of indigenous microbial communities.

Fine-tuning formulation and biological interaction of doxorubicin-loaded polymeric nanoparticles via electrolyte concentration modulation

Doxorubicin (DOX) is amongst the most widely used chemotherapeutic drugs against various cancers. However, its controlled biodistribution to the tumor site at the required pharmacokinetics profile remains challenging. In this work, a vast study of formulation parameters has been performed to control doxorubicin loading into polymeric nanoparticles in physiological conditions. Water-in-oil-in-water (W1/O/W2) template emulsions have been formulated, including doxorubicin in the internal water phase. Specifically, the system [Doxorubicin in aqueous solution (W1) / Pluronic F-127 (S) and PLGA in ethyl acetate (O)], [Polysorbate 80 (S) in water solution], using phosphate buffer on both aqueous phases at different electrolyte concentrations has been established. The first W1/O nano-emulsion was formed by high-speed homogenization, and the second O/W2 nano-emulsion was formed by the phase inversion composition method, a low-energy emulsification appropriated for pharmaceutical compounds. Although many previous studies had already used double emulsions for DOX encapsulation in nanofluids, here, for the first time, the salt concentration of the water phases has been varied to control the resulting doxorubicin and nanoparticle properties. The addition of high concentrations of electrolytes in both aqueous phases decreases the solubility and dissolution rates of the drug, leading to a high degree of DOX dimerization. This phenomenon significantly impacts the internalization and subcellular localization. Facilitating drug nuclear accumulation is of vital interest, and this is primarily achieved when doxorubicin is incorporated into nanoparticles formulated with PBS at low electrolyte concentrations (2.5 mM), which exhibit exceptional internalization properties. Thus, it has been demonstrated that doxorubicin loading in polymeric nanoparticles can be tuned by only varying salt concentrations of template W1/O/W2 emulsions. Consequently, our results show the adequacy of the double nano-emulsion templating for the generation of non-toxic DOX-loaded polymeric nanoparticles with different physicochemical properties and interaction with the cell surface that would allow their use for various anticancer therapies.

Multimodal lemongrass oil based topical nanoemulgel ingrained with ferulic acid for wound healing activity

The lemongrass oil (LMGO) obtained from Cymbopagan citratus betrays anti-bacterial and anti-oxidant properties. A natural anti-oxidant, ferulic acid (FA) is an angiogenic agent found in vegetables, fruits exhibiting potent anti-inflammatory activity aiding in wound healing process. This investigation was aimed to formulation and optimization of the FA loaded LMGO nanoemulsion (NE) by phase inversion composition method, that has not been well explored by using Box Behnken design (BBD). The surface-active parameters of surfactant mixture (Smix) were evaluated for the selection of Smix ratio in conjunction with conventional pseudo ternary phase diagram. The surface-active parameters included critical micelle concentration (CMC), surface excess concentration (Гmax), minimum surface area adsorbed by surfactant molecules (Amin), effectiveness of adsorption (Πcmc) along with Gibbs thermodynamic parameters for micellization and adsorption. The BBD was employed to optimize the formulation by studying the interaction effects of four independent variables including oil (X1), surfactant mixture (X2), stirring speed (X3), and stirring time (X4) on three responses such as, mean droplet size (Y1), polydispersity index (PDI) (Y2) and percentage transmittance (Y3). At the optimal variable levels (X1 = 10%;X2 = 30%;X3 = 500 rpm and X4 = 5 min), the responses were found to be 26.15 ± 0.58 nm, 0.04 ± 0.01 and 99.76 ± 0.06% for Y1, Y2, Y 3, respectively. The optimized NE exhibited stability in terms of droplet size, PDI, percentage transmittance and surface tension on 5, 10 and 100 times dilution with water. These findings may be useful for designing NE with low energy methods with greater kinetic stability for therapeutic applications. The FA content was determined and found be 98.11 ± 0.51%. The optimized FA loaded NE (FLGO) was incorporated with 2% carbopol®940 for the development of nanoemulgel. The developed FA loaded nanoemulgel (FLGO-G) system demonstrated the pseudoplastic behaviour, desirable for topical application. The blank lemongrass oil nanoemulsion loaded gel (LGO-G) and FLOG-G formulation showed 52.82 ± 0.33% and 75.62 ± 0.16% of DPPH free radical % inhibition. The formulations also showed in-vitro antibacterial activity against S. aureus. The in vivo wound healing efficacy of LGO-G and FLGO-G were studied in male wistar rat, the levels of IL-6 and TNF-α reduced to greater extent.

Encapsulation of Carvacrol-Loaded Nanoemulsion Obtained Using Phase Inversion Composition Method in Alginate Beads and Polysaccharide-Coated Alginate Beads.

Nanoemulsions have been widely studied as lipophilic compound loading systems. A low-energy emulsification method, phase inversion composition (PIC), was used to prepare oil-in-water nanoemulsions in a carvacrol-coconut oil/Tween 80®-(linoleic acid-potassium linoleate)/water system. The phase behaviour of several emulsification paths was studied and related to the composition range in which small-sized stable nanoemulsions could be obtained. An experimental design was carried out to determine the best formulation in terms of size and stability. Nanoemulsions with a very small mean droplet diameter (16-20 nm) were obtained and successfully encapsulated to add carvacrol to foods as a natural antimicrobial and antioxidant agent. They were encapsulated into alginate beads by external gelation. In order to improve the carvacrol kinetics release, the beads were coated with two different biopolymers: chitosan and pullulan. All formulations were analysed with scanning electron microscopy to investigate the surface morphology. The release patterns at different pHs were evaluated. Different kinetics release models were fitted in order to study the release mechanisms affecting each formulation. Chitosan-coated beads avoided the initial release burst effect, improving the beads' structure and producing a Fickian release. At basic pH, the chitosan-coated beads collapsed and the pullulan-coated beads moderately improved the release pattern of the alginate beads. For acid and neutral pHs, the chitosan-coated beads presented more sustained release patterns.

Polymer nanoparticles from low-energy nanoemulsions for biomedical applications.

The formulation of nanoemulsions by low-energy strategies, particularly by the phase inversion composition method, and the use of these nanoemulsions as templates for the preparation of polymer nanoparticles for biomedical applications are reviewed. The methods of preparation, nature of the components in the formulation, and their impact on the physicochemical properties, drug loading, and drug release are discussed. We highlight the utilization of ethyl cellulose, poly(lactic-co-glycolic acid), and polyurethane/polyurea in the field of nanomedicine as potential drug delivery systems. Advances are still needed to achieve better control over size distribution, nanoparticle concentration, surface functionalization, and the type of polymers that can be processed.

Nanoemulsion containing Yellow Monascus pigment : Fabrication, characterization, storage stability, and lipase hydrolytic activity in vitro digestion

The natural pigment of monascus is favored by human for its special coloring and physiological activity, and its development and application have attracted much attention. In this study, a novel corn oil-based nanoemulsion encapsulated with Yellow Monascus Pigment crude extract (CO-YMPN) was successfully prepared via the phase inversion composition method. The fabrication and stable conditions of the CO-YMPN including Yellow Monascus pigment crude extract (YMPCE) concentration, emulsifier ratio, pH, temperature, ionic strength, monochromatic light and storage time were investigated systemically. The optimized fabrication conditions were the emulsifier ratio (5:3 ratio of Tween 60 to Tween 80) and the YMPCE concentration (20.00% wt%)). Additionally, the DPPH radical scavenging capability of the CO-YMPN (19.47 ± 0.52%) was more excellent than each YMPCE or corn oil. Moreover, the kinetic analysis results based on Michaelis-Menten equation and constant revealed that CO-YMPN could improve lipase hydrolysis capacity. Therefore, the CO-YMPN complex had excellent storage stability and water solubility in the final water system, and the YMPCE showed brilliant stability.

Effect of surface functionalization and loading on the mechanical properties of soft polymeric nanoparticles prepared by nano-emulsion templating

Drug and gene delivery systems based on polymeric nanoparticles offer a greater efficacy and a reduced toxicity compared to traditional formulations. Recent studies have evidenced that their internalization, biodistribution and efficacy can be affected, among other factors, by their mechanical properties. Here, we analyze by means of Atomic Force Microscopy force spectroscopy how composition, surface functionalization and loading affect the mechanics of nanoparticles. For this purpose, nanoparticles made of Poly(lactic-co-glycolic) (PLGA) and Ethyl cellulose (EC) with different functionalizations and loading were prepared by nano-emulsion templating using the Phase Inversion Composition method (PIC) to form the nano-emulsions. A multiparametric nanomechanical study involving the determination of the Young's modulus, maximum deformation and breakthrough force was carried out. The obtained results showed that composition, surface functionalization and loading affect the nanomechanical properties in a different way, thus requiring, in general, to consider the overall mechanical properties after the addition of a functionalization or loading. A graphical representation method has been proposed enabling to easily identify mechanically equivalent formulations, which is expected to be useful in the development of soft polymeric nanoparticles for pre-clinical and clinical use.

Effect of surfactants and Co-surfactants in formulation of noni fruit extract in virgin coconut oil-based emulsion

This study aims to formulate and characterize the emulsion of Morinda citrifolia L. (Noni fruit) extract in virgin coconut oil (VCO) using the Phase Inversion Composition method (PIC). The chemical compositions with bioactivities in noni fruit extracts obtained from Soxhlet extraction method were analyzed by using Gas Chromatography-Mass Spectrometry to understand their potential uses. To formulate VCO-based emulsion, different types of surfactants (Cremophor EL, Cremophor RH 40, and Tween 80) and co-surfactants (Propylene glycol, Ethylene glycol, and Ethanol) were varied in concentration. The characteristics of VCO-based emulsions in terms of droplet size and stability were analyzed to find the optimal condition for stable emulsion. Among three types of surfactants, Cremophor RH 40 mixed with propylene glycol or ethylene glycol provided the most stable VCO-based emulsion in nanoscale droplet size with the minimal droplet size at 332 nm. The noni extracts were mixed in the optimized VCO-based formula at the VCO's concentration of 6, 8, and 10%. The results showed that the addition of noni extracts increased the droplet size of emulsion from nanometer scale to micrometer scale and reduced the emulsion stability. At the optimal condition, the mixture containing 4.5% VCO, 1.5% propylene glycol, and 0.3% Noni extract showed the smallest droplet size (1.1–1.85 μm), which was in the range of most commercial emulsions, with good stability in a 5-day period. This study provides a promising approach to formulate stable emulsions with low levels of surfactant and co-surfactant, which is extensively significant for commercial delivery systems.

Isoliquiritigenin Nanoemulsion Preparation by Combined Sonication and Phase-Inversion Composition Method: In Vitro Anticancer Activities

Isoliquiritigenin (ILQ) has a number of biological activities such as antitumor and anti-inflammatory effects. However, biomedical applications of ILQ are impeded by its poor aqueous solubility. Therefore, in this research, we prepared a novel ILQ-loaded nanoemulsion, i.e., ILQ-NE, which consisted of Labrafil® M 1944 CS (oil), Cremophor® EL (surfactant), ILQ, and phosphate-buffered saline, by employing a combined sonication (high-energy) and phase-inversion composition (low-energy) method (denoted as the SPIC method). The ILQ-NE increased the ILQ solubility ~1000 times more than its intrinsic solubility. It contained spherical droplets with a mean diameter of 44.10 ± 0.28 nm and a narrow size distribution. The ILQ loading capacity was 4%. The droplet size of ILQ-NE remained unchanged during storage at 4 °C for 56 days. Nanoemulsion encapsulation effectively prevented ILQ from degradation under ultraviolet light irradiation, and enhanced the ILQ in vitro release rate. In addition, ILQ-NE showed higher cellular uptake and superior cytotoxicity to 4T1 cancer cells compared with free ILQ formulations. In conclusion, ILQ-NE may facilitate the biomedical application of ILQ, and the SPIC method presents an attractive avenue for bridging the merits and eliminating the shortcomings of traditional high-energy methods and low-energy methods.

Rosmarinic Acid-Loaded Polymeric Nanoparticles Prepared by Low-Energy Nano-Emulsion Templating: Formulation, Biophysical Characterization, and In Vitro Studies.

Rosmarinic acid (RA), a caffeic acid derivative, has been loaded in polymeric nanoparticles made up of poly(lactic-co-glycolic acid) (PLGA) through a nano-emulsion templating process using the phase-inversion composition (PIC) method at room temperature. The obtained RA-loaded nanoparticles (NPs) were colloidally stable exhibiting average diameters in the range of 70–100 nm. RA was entrapped within the PLGA polymeric network with high encapsulation efficiencies and nanoparticles were able to release RA in a rate-controlled manner. A first-order equation model fitted our experimental data and confirmed the prevalence of diffusion mechanisms. Protein corona formation on the surface of NPs was assessed upon incubation with serum proteins. Protein adsorption induced an increase in the hydrodynamic diameter and a slight shift towards more negative surface charges of the NPs. The radical scavenging activity of RA-loaded NPs was also studied using the DPPH·assay and showed a dose–response relationship between the NPs concentration and DPPH inhibition. Finally, RA-loaded NPs did not affect the cellular proliferation of the human neuroblastoma SH-SY5Y cell line and promoted efficient cellular uptake. These results are promising for expanding the use of O/W nano-emulsions in biomedical applications.

Neem oil based nano-emulsion formulation by low energy phase inversion composition method: Characterization and antimicrobial activity

This study aimed to prepare neem oil based nano-emulsion by using the phase inversion composition (PIC) method (low energy) followed by its characterization and assessment for antibacterial effectiveness. Nano-emulsion with droplet size below 200 nm was prepared at 27 °C by stabilizing neem oil-in-water with surfactant blend (Tween 80/Span 80) at a 1:1 vol ratio with hydrophilic-lipophilic balance (HLB) value of 10.7. The single-phase formulation of neem oil nano-emulsion was characterized for droplet size, zeta potential and viscosity. In contrast to raw neem oil and ampicillin antibiotic drug, nano-emulsion formulation showed improved antimicrobial activity against human pathogenic bacteria.

Extraction and Microemulsion of Lupin Protein

In present study, protein and oil were extracted from sweet and bitter lupin that were used to define the phase behaviour of a three-component system (lupin oil, Tween 80/propylene glycol and water/lupin protein). Ternary phase diagrams were constructed and the optimum area of ternary phase diagrams corresponding to the formation of microemulsions were identified using emulsion titration method. Phase inversion composition method was applied, which involved the spontaneous formation of microemulsion, characterized by visual observation for their phase separation and optical clarity (e.g. transparency and opacity). Generally, o/w microemulsions were formed at a small region of the ternary phase diagrams with a relatively large ratio of water/lupin protein. Some differences between the sweet and bitter lupin diagrams were observed in regions, including bi- and multiphase, liquid crystals, gel and coarse emulsions. The physical characteristics of the microemulsions did not change with different storage temperatures.

Formulation, Physical and Chemical Stability of &lt;i&gt;Ocimum gratissimum&lt;/i&gt; L. Leaf Oil Nanoemulsion

Ocimum gratissimum L. leaf oil exhibited many pharmacological properties. This study aimed to formulate and evaluate the physical and chemical stability of O.gratissimum leaf oil nanoemulsion. O.gratissimum leaf oil was extracted by hydrodistillation. The major component of the essential oil eugenol, was analyzed by UV-Vis spectrophotometry. Nanoemulsions of O.gratissimum leaf oil were formulated using polysorbate 80, hyaluronic acid, poloxamer 188, and deionized water by phase inversion composition method. The hydrodynamic diameter, polydispersity index, and zeta potential value of O.gratissimum leaf oil nanoemulsion was evaluated by a dynamic light scattering technique. The %remaining of eugenol in the nanoemulsion was analyzed by UV-Vis spectrophotometry. The essential oil extracted from of O. gratissimum leaf oil was a clear, pale yellow color. The %yield of the essential oil was 0.15 ± 0.03% v/w. The size of the nanoemulsion was less than 106 nm. The polydispersity index of the nanoemulsion was ranging from 0.303 - 0.586 and the zeta potential value of the nanoemulsion was closely to zero, depending on the formulation component. O. gratissimum leaf oil at concentrations ranging from 0.002 - 0.012% v/v contained 35 - 41% of eugenol. The size of nanoemulsion was significantly decreased after storage at 4 °C, while significantly increased upon storage at 45 °C. The size of nanoemulsion stored at 30 °C did not significantly change. The %remaining of eugenol in the nanoemulsion was more than 90% after storage at 4 °C and 30 °C for 28 days. The percentage of eugenol remaining in the nanoemulsion stored at 45 °C was more than 85 - 90%, suggesting that the temperature affected the stability of eugenol in the nanoemulsion.

Preparation of polyoxypropylene surfactant-based nanoemulsions using phase inversion composition method and their application in oil recovery

Emulsification using phase inversion composition (PIC) was achieved by changing the composition of surfactants at a constant temperature. The method has great potential to scale up applications due to the ease in the formation of nanoemulsions and the relatively low energy involved. Surfactants containing composition-sensitive polyoxyethylene (POE) chains are widely used to prepare nanoemulsions using the PIC method. It is, therefore, anticipated that surfactants containing composition-sensitive polyoxypropylene (POP) chains can also be used to prepare nanoemulsions using the PIC method. The POP surfactant D230-2OA, containing short POP chains, was obtained from the electrostatic interactions between hydrophilic POP diamine (D230) and hydrophobic oleic acid (OA). The synthesized D230-2OA was used as an emulsifier in the preparation of the n-dodecane-in-water nanoemulsion using the PIC method. The effects of D230-2OA concentration, oil-to-surfactant weight ratio, and NaCl concentration on the droplet size of the nanoemulsions was investigated using dynamic light scattering (DLS). The morphology of the nanoemulsion was characterized using cryogenic transmission electron microscopy (cryo-TEM). The wettability of the crude oil–saturated quartz plate before and after treatment with nanoemulsions was obtained using contact angle measurement. A core flooding experiment demonstrated the efficiency of the diluted nanoemulsion in enhanced oil recovery, with an additional recovery of 21.30%. The nanoemulsion prepared with the POP surfactant as the emulsifier using the PIC method has wide application in petroleum recovery.

Oil-in-water nanoemulsion with reversible charge prepared by the phase inversion composition method

The phase inversion composition (PIC) method is to change the composition of the system to form nanoemulsion under constant temperature conditions. In this work, the nanoemulsion charge was regulated by changing the pH of the system to protonate and deprotonate N, N-dimethyldecanamide (DMDEA). The particle size and stability of the nanoemulsion were characterized by dynamic light scattering (DLS). Zeta potential (ζ) confirmed the electrification of nanoemulsion at different pH. Contact angle measurement revealed the influence of different electrification of nanoemulsion on wettability alteration. The wettability of quartz powder before and after nanoemulsion treatment was analyzed by Fourier-transform infrared spectroscopy (FTIR). The displacement experiment proved the efficiency of nanoemulsion in enhancing oil recovery, and an additional recovery of 17.36% was observed after subsequent water flooding. The prepared nanoemulsion with reversible charge has good application prospects in petroleum recovery.

Synthesis of Hierarchical Porous Silica by Sol‐Gel of Sodium Silicate and Nanoemulsion Templating: Effective Combination Conditions

AbstractHierarchical porous materials have attracted a considerable attention owing to the increased interest in their applications. Hierarchical Porous Silica (HPS) was synthesized by combining the sol‐gel of sodium silicate (SS) and oil in water nanoemulsion (O/W‐NE) templating. The oil droplets of NE acted as pore forming agent and the sol‐gel built the silica framework. The O/W‐NE was prepared by a low energy method, i. e., the phase inversion composition (PIC) method. The influence of pH of SS and NE on HPS was studied. The volume of ammonia, used to induce gelling, was studied as a factor influencing the HPS. The calcined samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), FTIR, N2 adsorption and small‐angel X‐ray scattering (SAXS). The results show that the microstructure is highly affected by pH and can be; macropores inserted in a dense matrix; a blend of a dense and a porous structure; or fully hierarchical porous silica. HPS has a specific surface area of 240 m2/g and a large pore volume (1.5 cm3/g) and a surface roughness of 2.95.

Polyglycerol Ester-Based Low Energy Nanoemulsions with Red Raspberry Seed Oil and Fruit Extracts: Formulation Development toward Effective In Vitro/In Vivo Bioperformance.

This study focuses on the development of biocompatible oil-in-water (O/W) nanoemulsions based on polyglycerol esters, as promising carriers for natural actives: red raspberry seed oil—RO and hydro-glycolic fruit extracts from red raspberry—RE and French oak—FE. Nanoemulsions were obtained via phase inversion composition (PIC) method at room temperature by dilution of microemulsion phase, confirmed by visual appearance, percentage of transmittance, microscopic, rheological and differential scanning calorimetry (DSC) investigations. The results have shown that the basic RO-loaded formulation could be further enriched with hydro-glycolic fruit extracts from red raspberry or French oak, while keeping a semi-transparent appearance due to the fine droplet size (Z-ave: 50 to 70 nm, PDI value ≤ 0.1). The highest antioxidant activity (~92% inhibition of the DPPH radical) was achieved in the formulation containing both lipophilic (RO) and hydrophilic antioxidants (FE), due to their synergistic effect. The nanoemulsion carrier significantly increased the selective cytotoxic effect of RO towards malignant melanoma (Fem-X) cells, compared to normal human keratinocytes (HaCaT). In vivo study on human volunteers showed satisfactory safety profiles and significant improvement in skin hydration during 2 h after application for all nanoemulsions. Therefore, polyglycerol ester-based nanoemulsions can be promoted as effective carriers for red raspberry seed oil and/or hydro-glycolic fruit extracts in topical formulations intended for skin protection and hydration.

Development of a hydrogen peroxide-responsive and oxygen-carrying nanoemulsion for photodynamic therapy against hypoxic tumors using phase inversion composition method

Photodynamic therapy (PDT) has become an attractive tumor treatment modality because of its noninvasive feature and low side effects. However, extreme hypoxia inside solid tumors severely impedes PDT therapeutic outcome. To overcome this obstacle, various strategies have been developed recently. Among them, in situ oxygen generation, which relies on the decomposition of tumor endogenous H2O2, and oxygen delivery tactic using high oxygen loading capacity of hemoglobin or perfluorocarbons, have been widely studied. The in situ oxygen generation strategy has high specificity to tumors, but its oxygen-generating efficiency is limited by the intrinsically low tumor H2O2 level. In contrast, the oxygen delivery approach holds advantage of high oxygen loading efficiency, nevertheless lacks tumor specificity. In this work, we prepared a nanoemulsion system containing H2O2-responsive catalase, highly efficient oxygen carrier perfluoropolyether (PFPE), and a near-infrared (NIR) light activatable photosensitizer IR780, to combine the high tumor specificity of the in situ oxygen generation strategy and the high efficiency of the oxygen delivery strategy. This concisely prepared nanoplatform exhibited enhanced and H2O2-controllable production of singlet oxygen under light excitation, satisfactory cytocompatibility, and ability to kill cancer cells under NIR light excitation. This highlights the potential of this novel nanoplatform for highly efficient and selective NIR light mediated PDT against hypoxic tumors. This research provides new insight into the design of intelligent nanoplatform for relieving tumor hypoxia and enhancing the oxygen-dependent PDT effects in hypoxic tumors.

Influence of hydrocolloid addition on physical properties and rheology of olive oil in bitter orange juice (O/W) nano-emulsions prepared with blends of different surfactants

Olive oil-in-bitter orange juice (O/W) nano-emulsions were prepared by Phase Inversion Composition method. Binary combinations of Tween80, Span20, sucrose monopalmitate and sunflower lecithin were used as surfactants. Influence of type (locust bean gum, xanthan gum, iota-carrageenan) and concentration (0–0.40%) of added hydrocolloid upon physical (visual appearance, transparency (T), microstructure, particle size (D43)) and rheological properties (consistency index (K), flow index (n), apparent viscosity (Ƞa ) of nano-emulsions were investigated. The lowest D43 (0.143 µm–0.569 µm) and Ƞa (2.46–2.51 cp) accompanied with the highest T (47.50–70.65%) were observed in nano-emulsions prepared without hydrocolloid. Significant negative correlation was found between D43, Ƞa and T, i.e., hydrocolloid addition increased the Ƞa and D43, as well as T loss. The Power Law model was well-suited to the experimental data (R2 >0.9534). The n values of Tween80/Span20, Tween80/SL and Tween80/SMP nano-emulsions in the absence of hydrocolloid were 1.00, 0.98 and 0.99, respectively, which presents a Newtonian behavior. The n values of Tween80/Span20, Tween80/SL and Tween80/SMP nano-emulsions in the presence of LBG, XA and i-CARR at varying concentrations were in the range of 0.16–0.99, 0.13–0.98 and 0.15–0.97, respectively, which presents Non-Newtonian shear-thinning behavior. Same type of hydrocolloid showed similar trend in all nano-emulsions regardless of emulsion composition. There has been significant positive correlation between D43, K and Ƞa , while there has been significant negative correlation between T, n and Ƞa .