Stable Nanoemulsions Research Articles

Stable nanoemulsions for poorly soluble curcumin: From production to digestion response in vitro

Curcumin, a polyphenol, can induce anticancer activity depending on dose. However, oral curcumin administration is limited by its low bioavailability due to aqueous insolubility and instability against physiological conditions. This study aims at formulating nanoemulsions by phase inversion temperature to enhance curcumin loading, stability, antioxidant performance, bioaccessibility, and in vitro absorption. The selection mechanisms for oil phase (coconut oil), surfactant (polyoxyl 40 hydrogenated castor oil), co-surfactant (soy phospholipid), and aqueous phase (2 % wt citrate buffer at pH 4.5) are established. The nanoemulsions show tunable mean droplet size (26–129 nm), high curcumin loading (9.53 ± 0.49 mg/mL), polydispersity < 0.3, and ζ-potential < -26 mV. Nanoencapsulation increases curcumin photostability by 36–42 % and the antioxidant activity after 24-hour UV radiation is unchanged (P > 0.05). The curcumin nanoemulsions show ∼ 11 %, 24 %, and 57 % higher retention and ∼ 10 %, 12 %, and 17 % higher antioxidant activity than raw curcumin after 3-hour simulated gastric, intestinal, and physiological incubations, respectively. During in vitro digestion and absorption, the encapsulated curcumin shows higher bioaccessibility and absorption than free curcumin (P < 0.05). The samples are stable during 4-week storage at 4˚C and room temperature without preservatives. These findings suggest the potential to develop a nanoencapsulation strategy, particularly for an oral delivery system of oil-soluble drugs.

Development of a novel squalene/α-tocopherol-based self-emulsified nanoemulsion incorporating Leishmania peptides for induction of antigen-specific immune responses

Vaccination has emerged as the most effective strategy to confront infectious diseases, among which is leishmaniasis, that threat public health. Despite laborious efforts there is still no vaccine for humans to confront leishmaniasis. Multi-epitope protein/peptide vaccines present a number of advantages, however their use along with appropriate adjuvants that may also act as antigen carriers is considered essential to overcome subunit vaccines’ low immunogenicity. In the present study, a stable self-emulsified nanoemulsion was developed and double-adjuvanted with squalene and α-tocopherol. The prepared nanoemulsion droplets exhibited low cytotoxicity in a certain range of concentrations, while they were efficiently taken up by macrophages and dendritic cells in vitro as well as in vivo in secondary lymphoid organs. To further characterize nanoformulation’s potent antigen delivery capability, three multi-epitope Leishmania peptides were incorporated into the nanoemulsion. Peptide encapsulation resulted in dendritic cells’ functional differentiation characterized by elevated levels of maturation markers and intracellular cytokine production. Intramuscular administration of the nanoemulsion incorporating Leishmania peptides induced antigen-specific spleen cell proliferation as well as elicitation of CD4+ central memory cells, supporting the potential of the developed nanoformulation to successfully act also as an antigen delivery vehicle and thus encouraging further preclinical studies on its vaccine candidate potency.

Enhancing stability and antimicrobial activity of spearmint essential oil nanoemulsion through formulation optimization by mixture experimental design and in vitro drug release study

Spearmint essential oil (SEO) has been widely recognized for its therapeutic properties in treating gastrointestinal, respiratory, carminative, diuretic, antispasmodic, and sedative ailments. Moreover, it is commonly utilized as a flavoring agent in various food and beverage products. However, the effectiveness of SEO for medicinal purposes is hindered by its limited water solubility. Hence, the objective of this research was to determine the optimal conditions for producing a nanoemulsion of SEO by measuring turbidity through a mixture experimental design. The study aimed to investigate the impact of different formulation variables on turbidity as the response variable. These variables included PEG-40 hydrogenated castor oil (HCO) (1%–2% w/w), Tween 80 (1%–3% w/w), Tween 20 (1%–3% w/w), propylene glycol (PG) (5%–20% w/w), and polyethylene glycol 400 (5%–20% w/w). The results of the experimental design showed that the obtained data could be adequately fitted in a second-order polynomial model for the prediction of nanoemulsion turbidity with a multiple regression coefficient of 0.9704. The particle size value at the optimum condition was 81.28 nm, which was matched with the result of transmission electron microscopy (TEM). The thermodynamic and long-term stability of the prepared nanoemulsion were investigated. Furthermore, the developed nanoemulsion exhibited better antimicrobial activity against E. coli. In vitro release testing showed that the release of the optimized nanoemulsion was significantly increased. This study demonstrated that SEO is capable of forming stable nanoemulsions for use in delivery systems of flavoring agents in the food industry.

Physicochemical characterization and environmental stability of a curcumin-loaded Pickering nanoemulsion using a pea protein isolate-dextran conjugate via the Maillard reaction

This study investigated pea protein isolate (PPI) and dextran (DX) conjugates produced via the Maillard reaction as Pickering stabilizers for various food applications. The results found that as heating time increased (0–5 h), the grafting degree heightened. The PPI-DX conjugate exhibited a rough porous surface in contrast to native PPI, accompanied by changes in molecular weight and secondary structure. Additionally, the aggregation of low-solubility PPI was partially inhibited due to the contribution of increased solubility and reduced surface hydrophobicity by glycation. Curcumin-loaded Pickering nanoemulsions stabilized with PPI-DX had smaller droplets and higher curcumin encapsulation (greater than80 %) than PPI-stabilized nanoemulsions. PPI-DX adsorbed on the interface showed improved physical stability compared to PPI alone, even after various pH conditions and three heat treatments. The nanoemulsion stabilized with PPI-DX demonstrated improved apparent viscosity and dispersion stability. These findings highlight the effectiveness of PPI-DX conjugates as stabilizers for developing stable and functional Pickering nanoemulsions.

A Reversibly Thermoresponsive, Theranostic Nanoemulgel for Tacrolimus Delivery to Activated Macrophages: Formulation and In Vitro Validation.

Despite long-term immunosuppression, organ transplant recipients face the risk of immune rejection and graft loss. Tacrolimus (TAC, FK506, Prograf®) is an FDA-approved keystone immunosuppressant for preventing transplant rejection. However, it undergoes extensive first-pass metabolism and has a narrow therapeutic window, which leads to erratic bioavailability and toxicity. Local delivery of TAC directly into the graft, instead of systemic delivery, can improve safety, efficacy, and tolerability. Macrophages have emerged as promising therapeutic targets as their increased levels correlate with an increased risk of organ rejection and a poor prognosis post-transplantation. Here, we present a locally injectable drug delivery platform for macrophages, where TAC is incorporated into a colloidally stable nanoemulsion and then formulated as a reversibly thermoresponsive, pluronic-based nanoemulgel (NEG). This novel formulation is designed to undergo a sol-to-gel transition at physiological temperature to sustain TAC release in situ at the site of local application. We also show that TAC-NEG mitigates the release of proinflammatory cytokines and nitric oxide from lipopolysaccharide (LPS)-activated macrophages. To the best of our knowledge, this is the first TAC-loaded nanoemulgel with demonstrated anti-inflammatory effects on macrophages in vitro.

Characterization, in-vitro digestion, antioxidant, anti-hyperlipidemic and antibacterial activities of Zanthoxylum bungeanum Maxim essential oil nano-emulsion

A stable nano-emulsion was successfully prepared using Tween 80 (T-80) as an emulsifier, so as to overcome the defects of the Zanthoxylum bungeanum Maxim essential oil (ZMEO) and improve its bioavailability. This study investigated the physical properties and biological activities of the ZMEO-NE, including rheological characteristics, particle size, in-vitro digestion, antioxidant, anti-hyperlipidemia, and antibacterial activity. The ZMEO-NE was a non-Newtonian fluid with an average particle size less than 150 nm, and remained stable in the oral environment, but was successively digested and decomposed in the gastrointestinal environment. In addition, the ZMEO-NE had significant antioxidant, anti-hyperlipidemic, and antibacterial activities, and the antibacterial mechanism was that the disrupted cell membranes of bacteria led to bacterial death. Therefore, the ZMEO-NE can be applied as a natural antioxidant or preservative for food preservation, and also have potential value in treating hyperlipidemia.

Characterization of Nanoemulsions Stabilized with Different Emulsifiers and Their Encapsulation Efficiency for Oregano Essential Oil: Tween 80, Soybean Protein Isolate, Tea Saponin, and Soy Lecithin.

The use of the appropriate emulsifier is essential for forming a stable nanoemulsion delivery system that can maintain the sustained release of its contents. Health concerns have prompted the search for natural biopolymers to replace traditional synthetic substances as emulsifiers. In this study, an oregano essential oil (OEO) nanoemulsion-embedding system was created using soybean protein isolate (SPI), tea saponin (TS), and soy lecithin (SL) as natural emulsifiers and then compared to a system created using a synthetic emulsifier (Tween 80). The results showed that 4% Tween 80, 1% SPI, 2% TS, and 4% SL were the optimal conditions. Subsequently, the influence of emulsifier type on nanoemulsion stability was evaluated. The results revealed that among all the nanoemulsions, the TS nanoemulsion exhibited excellent centrifugal stability, storage stability, and oxidative stability and maintained high stability and encapsulation efficiency, even under relatively extreme environmental conditions. The good stability of the TS nanoemulsion may be due to the strong electrostatic repulsion generated by TS molecules, which contain hydroxyl groups, sapogenins, and saccharides in their structures. Overall, the natural emulsifiers used in our study can form homogeneous nanoemulsions, but their effectiveness and stability differ considerably.

Nanoemulsions of synthetic rhamnolipids act as plant resistance inducers without damaging plant tissues or affecting soil microbiota.

Plant pathogens and pests can cause significant losses in crop yields, affecting food security and the global economy. Many traditional chemical pesticides are used to combat these organisms. This can lead to the development of pesticide-resistant strains of pathogens/insects and negatively impact the environment. The development of new bioprotectants, which are less harmful to the environment and less likely to lead to pesticide-resistance, appears as a sustainable strategy to increase plant immunity. Natural Rhamnolipids (RL-Nat) are a class of biosurfactants with bioprotectant properties that are produced by an opportunistic human pathogen bacterium. RL-Nat can act as plant resistance inducers against a wide variety of pathogens. Recently, a series of bioinspired synthetic mono-RLs produced by green chemistry were also reported as phytoprotectants. Here, we explored their capacity to generate novel colloidal systems that might be used to encapsulate bioactive hydrophobic compounds to enhance their performance as plant bioprotectants. The synthetic mono-RLs showed good surfactant properties and emulsification power providing stable nanoemulsions capable of acting as bio-carriers with good wettability. Synthetic RLs-stabilized nanoemulsions were more effective than RLs suspensions at inducing plant immunity, without causing deleterious effects. These nanoemulsions were innocuous to native substrate microbiota and beneficial soil-borne microbes, making them promising safe bio-carriers for crop protection.

Pharmaceutical Carrier’s for Topical Drug Delivery System

Beginning with a revenue breakdown of this specific market, this study seeks to describe the intricate world of drug carriers. A quick introduction of various different types of traditional and cutting-edge drug carrier systems is provided in the section that follows.Avariety of topical active substances, such as sunscreen ingredients, corticosteroids, and antibacterial, antifungal, and antiviral agents, can be delivered via foam technology. Ointments are semisolids used for external skin or mucous membrane treatment. Less than 20% of them often contain water and volatiles. Targeted medication delivery to and through the skin has a lot of potential using nano systems like micro emulsions and nano emulsions. By lowering surface and inter facial tension and increasing the viscosity of the aqueous phase, nanoemulgel improves a stable nano emulsion formulation. The various carrier types that the authors used in their formulation and conclusion have been added as a final effort for this work, highlighting the need to establish a strong double link between the newly developed industrial processes and the flexibility of medication delivery systems that is so desperately neededfor use with people.&#x0D; &#x0D;

Development of bean-based emulgels for 3D printing applications: Feasibility for dysphagia diets

Emulgels could be used as edible inks for individuals with special needs. The purpose of this work was to formulate a 3D printable low-oil emulgel by evaluating the effect of incorporating gelatin in a bean-based nanoemulsion stabilized by high-pressure homogenization (HPH) suitable for a dysphagia diet. The effect of physicochemical properties and printing parameters of the emulsion network were evaluated for printability, dimensional stability, and textural properties. HPH produced stable nanoemulsions using pressures >200 MPa and 5% bean protein. Adding gelatin decreased NH and COO vibrations, increased hydrogen bonding, and created self-supporting emulgels when the gelatin concentration was >1.5%. Printing performance, dimensional stability, and textural properties depended on the gelatin concentration and printing parameters, whose improvement enabled precise, time-stable, and swallow-safe shapes with 2.5% gelatin. In conclusion, stable emulgels can be used in 3D printing, facilitating the design of colloidal food systems with customized textures and nutritional properties for individuals with dysphagia.

A green versatile packaging based on alginate and anthocyanin via incorporating bacterial cellulose nanocrystal-stabilized camellia oil Pickering emulsions

This study aims to develop a versatile intelligent packaging based on alginate (Alg) and anthocyanin (Ant) by incorporating bacterial cellulose nanocrystal-stabilized camellia oil Pickering emulsions. Firstly, bacterial cellulose nanocrystals (BCNs) matrix produced from kombucha was incorporated with camellia oil into via ultrasonic triggering, forming a stable and multifunctional camellia oil-bacterial cellulose nanocrystal Pickering nanoemulsions (CBPE). The microstructure and rheology results of the emulsion confirmed the stabilized preparation of CBPE. Subsequently, the CBPE was integrated into the three-dimensional network structure composed of alginate/anthocyanin. The composite film (Alg-Ant-CBPE) was designed through Ca2+ crosslinking, intermolecular hydrogen bonding and dehydration condensation. The fabricated color indicator films with different concentrations of CBPE (0.1 %–0.4 %), showed varying degree of improvement in hydrophobicity, UV shielding, mechanical strength, thermal stability, water vapor barrier properties and antioxidant capacities. When applied to yogurt, the Alg-Ant-CBPE4 exhibited more pronounced color changes compared to Alg-Ant, enabling visual detection of food freshness. In conclusion, the incorporation of Pickering nanoemulsion provides an effective and promising approach to enhance the performance of polysaccharide-based intelligent packaging.

Multi-charged nanoemulsion for photodynamic treatment of glioblastoma cell line in 2D and 3D in vitro models

Multi-charged nanoemulsions (NE) were designed to deliver Cannabidiol (CBD), Indocyanine green (ICG), and Protoporphyrin (PpIX) to treat glioblastoma (GBM) through Photodynamic Therapy (PDT). The phase-inversion temperature (PIT) method resulted in a highly stable NE that can be scaled easily, with a six-month shelf-life. We observed the quasi-spherical morphology of the nanoemulsions without any unencapsulated material and that 89% (± 5.5%) of the material was encapsulated. All physicochemical properties were within the expected range for a nanostructured drug delivery system, making these multi-charged nanoemulsions promising for further research and development. NE-PIC (NE-Protoporphyrin + Indocyanine + CBD) was easily internalized on GBM cells after three hours of incubation. Nanoemulsion (NE and NE-PIC) did not result in significant cytotoxicity, even for GBM or non-tumorigenic cell lines (NHF). Phototoxicity was significantly higher for the U87MG cell than the T98G cell when exposed to: visible (430 nm) and infrared (810 nm) laser light, with a difference of about 20%. From 50 mJ.cm−2, the viability of GBM cell lines decreases significantly, ranging from 65% to 85%. The NE-PIC was also effective for inhibiting cell proliferation into a 3D spheroidal GBM cell model, which is promising for mimicking the tumor cell environment. Irradiation at 810 nm was more effective in treating spheroid due to its deeper penetration in complex structures. NE-PIC has the potential as a drug delivery system for photoinactivation and photo diagnostic of GBM cell lines, taking advantage of the versatility of its active components.

Formulation and Characteristics of Edible Oil Nanoemulsions Modified with Polymeric Surfactant for Encapsulating Curcumin.

Curcumin (Cur) is a beneficial phytochemical with numerous health advantages. However, its limited solubility in oil and poor stability hinder its potential for biomedical applications. In this study, we employed a mixture of food-grade Tween 60, a polymeric surfactant, and Span 60 to adjust the hydrophilic lipophilic balance number (HLBt) and prepared nanoemulsions (NEs) of coconut oil (Cc oil) as carriers for Cur. The effects of HLBt values, surfactant-to-oil ratio, and oil ratio on the physicochemical characteristics of the food-grade oil-NEs were investigated using dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, fluorescence polarization spectroscopy, and viscometry. Increasing the addition ratio of Tween 60 in the NEs, thereby increasing the HLBt, resulted in a reduction in NE size and an improvement in their storage stability. The temperature and size of the phase transition region of the NEs decreased with increasing HLBt. NEs with higher HLBt exhibited a disordering effect on the intra-NE molecular packing of Cc oil. NEs with high HLBt displayed low viscosity and demonstrated nearly Newtonian fluid behavior, while those with lower HLBt exhibited pseudoplastic fluid behavior. Cur was effectively encapsulated into the Cc oil-NEs, with higher encapsulation efficiency observed in NEs with higher HLBt values. Furthermore, the Cur remaining activity was significantly enhanced through encapsulation within stable NEs. The biocompatibility of the Cc oil-NEs was also demonstrated in vitro. In summary, this study highlights the preparation of stable NEs of Cc oil by adjusting the HLBt using Tween 60, facilitating effective encapsulation of Cur. These findings provide valuable insights for the development of Cur carriers with improved solubility, stability, and bioavailability.

Formulation Development and Evaluation of Apremilast Nanoemulsion

Apremilast is a selective phosphodiesterase 4 inhibitor administered orally in the treatment of moderate-to-severe plaque psoriasis and active psoriatic arthritis. It is classified as class IV drug as per BCS classification so it indicates low solubility and lower permeability through the skin. Therefore the objective of the research is to improve permeability of Apremilast through the skin and improve solubility by using oil and surfactant by formulating Nanoemulsion. Nanoemulsion was prepared by selecting Captex 355, Cremophore RH 40, Labrafil and Propylene glycol as the oil, surfactant,co-surfactant and co-solvent respectively after solubility study. Pseudo-ternary phase diagrams were constructed to find out the optimum ratio of oil: Smix (surfactant: co-Surfactant). Simple lattice design was applied to the optimization of the prepared nanoemulsion. The nanoemulsion was evaluated for Physical parameter, pH, Droplet size, zeta potential, in-vitro diffusion study etc. Results of Droplet size measurements, zeta potential and % drug diffusion indicated A5 batch optimized batch than other formulation of the nanoemulsion. So, optimized formulation further tested for Skin irritation study and stability study.The Apremilast loaded stable Nanoemulsion system was prepared and various process variables were evaluated. Batch A5 was selected as an optimized batch containing 10 % Captex 355, 40 % Smix (Cremophore RH 40 and Labrafil) and 50% water. Optimized batch was found to be stable after three month at ambient condition of temperature and humidity, giving reproducible results when evaluated.

Surface protection of wood using cerium oxide nanoparticles dispersed paraffin wax nanoemulsion

Exposure to solar UV radiation and other environmental factors promotes the degradation and reduces the serviceability of the wood material under outdoor use. Oils and waxes have been found to be promising solutions for wood protection. This study elucidates the use of paraffin wax based emulsions incorporated with cerium oxide nanoparticles to improve weathering performance of wood. For this purpose, paraffin wax nanoemulsions were prepared by ultrasonication method using tween 80 as surfactant. Cerium oxide nanoparticles (conc. 0.5- to 2%) were added to provide protection against degradation caused by solar UV radiation. The storage stability of nano emulsion was assessed over a period of 30 days by measuring effective particle size and zeta potential. The microstructure of nanoemulsions was observed by optical microscopy and distribution of CeO2 nanoparticles on coated wood was observed through scanning electron microscopy (SEM). The chemical changes were analyzed by Fourier Transform Infrared spectroscopy (FTIR). Wood specimens of Pinus radiata coated with nanoemulsions were subjected to the accelerated weathering tests for 500h. The time dependent changes in surface color of uncoated and coated wood samples were examined. Moreover, the chemical changes on exposed wood surfaces were analyzed by ATR-FTIR spectroscopy. Stable and homogenous nanoemulsions with particle diameter between 200 and 400 nm were formed and exhibited excellent storage stability. Results of color changes showed that maximum degradation was observed in uncoated wood whereas wood coated with paraffin wax nanoemulsion alone could not improve the UV resistance. However, the addition of cerium oxide nanoparticles proved to be efficient in controlling the color changes on wood surfaces. The degradation of wood components reduced significantly in cerium oxide coated wood which was confirmed by FTIR results.

Preparation, characterization and properties of cinnamon essential oil nano-emulsion formed by different emulsifiers

Essential oil has unstable properties and low bioavailability. In order to improve these problems, with the help of ultrasonic wave, stable nano-emulsions were prepared with different emulsifiers. In this experiment, the formation of nano-emulsions with different emulsifiers at different concentrations was studied, including sodium caseinate (SC), whey glycoprotein (WGP), soy protein isolate (SPI) and Tween 80. Meanwhile, we studied the effect of ultrasonic cell disruption apparatus and homogenizer on the particle size of nano-emulsions. Cinnamon essential oil nano-emulsion prepared under the optimum emulsifier and its concentration has good microstructure and rheological properties. The stability of cinnamon essential oil nano-emulsion in different environments was studied, including centrifugation, freeze-thaw, heating-freezing and long-term (30 d) stability. The nano-emulsion of cinnamon essential oil is stable in emulsifiers. The nano-emulsions prepared by different emulsifiers has different particle sizes in different environments and their advantages and disadvantages are compared. Finally, how different nano-emulsion were digested in vitro was also studied. The in vitro digestion of nano-emulsion by different emulsifiers was simulated. Its properties include particle size, zeta potential and polymer dispersion index (PDI).

Study of nanoemulsions using carvacrol/MCT-(Oleic acid-potassium oleate)/ Tween 80 ®- water system by low energy method

Carvacrol is studied in different fields due to its microbial and antioxidant properties. Its use is limited because of the water insolubility and its strong taste. To overcome these problems, carvacrol has been successfully loaded into nanoemulsions. The low-energy emulsification method Phase Inversion Composition (PIC) is used to prepare oil-in-water nanoemulsions in the carvacrol/medium chain triglycerides (MCT)-(oleic acid-potassium oleate/Tween 80 ®)-water system. Oleic acid acts as a co-surfactant when it is neutralized with KOH along the emulsification path changing the spontaneous curvature of the interface when increasing the HLB number from 1 for the oleic acid to 20 for the potassium oleate and, therefore, changing the HLB number of the surfactant mixture. The phases diagrams are studied in order to understand the behaviour of the system and to establish the composition range where nanoemulsions can be obtained. Nanoemulsions are formed when the emulsification path crosses a region of direct or planar structure without excess of oil. Experimental design is performed in order to study the influence of composition variables as carvacrol/MCT ratio and (oleic-oleate)/Tween 80 ® ratio (OL-OT/T80 ratio) on the diameter of the nanoemulsions and their stability. It has been observed the importance of the HLB number of the surfactants mixture in order to obtain small-sized stable nanoemulsions. Surface response graphic shows that (OL-OT)/T80 ratio is a significant parameter in the mean diameter of the nanoemulsions. A minimum diameter is obtained for a (OL-OT)/T80 ratio 45/55 due to the fact that ratio is near the preferred HLB of the oil mixture and the emulsification path contains a wide liquid crystal monophasic region with all the oil incorporated in the structure.Diameters of 19 nm for carvacrol/MCT ratio of 30/70 or diameters of 30 nm for ratios of 45/55 with high stability values presented a good potential to be incorporated into edible films in the future.Regarding nanoemulsions stability an optimum value is also observed for a carvacrol/MCT ratio.The addition of another carrier oil as olive oil instead of MCT showed an improvement of the nanoemulsions stability against Ostwald ripening, probably due to the smaller solubility of olive oil. The use of olive oil does not significantly change the diameter of the nanoemulsion.

Construction and formulation optimization of prothioconazole nanoemulsions for the control of Fusarium graminearum: Enhancing activity and reducing toxicity

In this study, the optimal emulsifier for prothioconazole nanoemulsions was initially screened based on appearance, microscopic observation, mean droplet size and polydispersity index (PDI). In addition, the BoxBehnken design method is adopted, and the optimal formula is screened with an emulsification time, emulsifier content, and solvent content as a single factor. On this basis, the nanoemulsion meets FAO standards for various indicators. The contact angle of droplets on wheat leaves was significantly reduced. This nanoemulsion also showed good inhibitory activity against Fusarium graminearum (EC50 =1.94 mg L−1), low acute toxicity to zebrafish (LC50 =26.35 mg L−1) and good biosafety to BEAS-2B cells. The nanoemulsion reduced the adverse effects of pesticide on wheat seed germination and growth. This study can help promote the design and manufacture of stable, efficient and safe agricultural nanoemulsions, and is expected to benefit the sustainable development of green plant protection.

Synthesis of polyglycerol fatty acid esters catalyzed by lipase and evaluation of its emulsification properties

The present study investigated the physicochemical properties of the newly synthesized polyglycerol fatty acid esters (PGFEs) and their potential application as food emulsifiers. It turned out that the complete removal of glycerol from crude polyglycerol was achieved by optimizing the molecular distillation temperature (120 °C). Moreover, novozym 435 was used to catalyze the synthesis of PGFEs with different aliphatic chain lengths, and the esterification rate of the obtained products was 93%∼98%. The characteristic absorption peak of the ester carbonyl group was displayed at 1738 cm−1, and that of C–O–C on the ether bond was at 1100 cm−1 and 1048 cm−1. Therefore, the synthesis can be determined to be PGFEs. Their hydrophilic lipophilic balance (HLB) values are >7, which can be used as oil-in-water emulsifiers. When curcumin nanoemulsions were constructed by PGFEs with various aliphatic chains as emulsifiers, it was found that all PGFEs in C10∼C18 can form stable curcumin nanoemulsions (encapsulation rate was >95%). PGFEs with longer aliphatic chains can stabilize nanoemulsions more efficiently (larger droplet sizes and lower ζ-electric potential), and showed better storage and UV stability. Whereas, medium-chain PGFEs emulsions, especially PGC, showed the best curcumin release efficiency, which theoretically supported the application of PGFEs to functional emulsion products.

A Biosurfactant Cocktail-Based Formula for the Formulation of Stable Skin-Care Cosmetic Nanoemulsion

A Biosurfactant Cocktail-Based Formula for the Formulation of Stable Skin-Care Cosmetic Nanoemulsion