Development of a nano-emulsion based multivalent protein subunit vaccine against Pseudomonas aeruginosa

Pseudomonas aeruginosa (Pa) is an opportunistic bacterial pathogen responsible for severe hospital acquired infections in immunocompromised and elderly individuals. Emergence of increasingly drug resistant strains and the absence of a broad-spectrum prophylactic vaccine against both T3SA+ (type III secretion apparatus) and ExlA+/T3SA- Pa strains worsen the situation in a post-pandemic world. Thus, we formulated a candidate subunit vaccine (called ExlA/L-PaF/BECC/ME) against both Pa types. This bivalent vaccine was generated by combining the C-terminal active moiety of exolysin A (ExlA) produced by non-T3SA Pa strains with our T3SA-based vaccine platform, L-PaF, in an oil-in-water emulsion. The ExlA/L-PaF in ME (MedImmune emulsion) was then mixed with BECC438b, an engineered lipid A analogue and a TLR4 agonist. This formulation was administered intranasally (IN) to young and elderly mice to determine its potency across a diverse age-range. The elderly mice were used to mimic the infection seen in elderly humans, who are more susceptible to serious Pa disease compared to their young adult counterparts. After Pa infection, mice immunized with ExlA/L-PaF/BECC/ME displayed a T cell-mediated adaptive response while PBS-vaccinated mice experienced a rapid onset inflammatory response. Important genes and pathways were observed, which give rise to an anti-Pa immune response. Thus, this vaccine has the potential to protect aged individuals in our population from serious Pa infection.

The role of turmeric and black pepper oil nanoemulsion in attenuating cytokine storm triggered by duck hepatitis A virus type I (DHAV-I)-induced infection in ducklings

The cytokine storm induced by duck hepatitis A virus type 1 (DHAV-1) infection significantly contributes to severe, rapid deaths and economic losses in the duck industry in Egypt. This study aimed to investigate the potential inhibitory effect of a nanoemulsion containing turmeric and black pepper oil on the immune response and pathogenesis of DHAV-1 in ducklings. A total of 105 ducklings from nonvaccinated breeders were divided into 5 experimental groups, each comprising 21 birds. The negative control group (G1) remained noninfected with DHAV-1 and nontreated with nanoemulsion, while the positive control group (G2) was infected with DHAV-1 but not treated with nanoemulsion. The other 2 groups (G3, the supplemented group which was noninfected with DHAV-1), and group 4 (the prophylactic group G4) which was infected with DHAV-1, both received nanoemulsion throughout the experiment. Group 5 (G5, the therapeutic group), on the other hand, which was infected with DHAV-1 received nanoemulsion only from the onset of clinical signs. At 5 days old, the ducklings in the positive control (G2), the prophylactic (G4), and the therapeutic group (G5) were infected with DHAV-1. All the ducklings in the infected groups exhibited depression, anorexia, and opisthotonos, and their livers displayed various degrees of ecchymotic hemorrhage, liver enlargement, and microscopic pathological lesions. Notably, the positive control group (G2) experienced the most severe and pronounced effects compared to the other infected groups treated with the nanoemulsion. Meanwhile, the viral RNA loads were lower in the liver tissues of the infected ducklings treated with the nanoemulsion (G4, and G5) compared to the positive control group G2. Additionally, the nanoemulsion effectively modulated proinflammatory cytokine expression, antioxidant enzymes, liver enzymes, and lipid profile of treated ducklings. In conclusion, the turmeric and black pepper oil nanoemulsion has the potential to be a therapeutic agent for regulating and modulating the immune response, decreasing DHAV-1-induced cytokine storms, and minimizing mortality and economic losses in the duck business. More research is needed to understand how turmeric and black pepper oil nanoemulsion alleviates DHVA-1-induced cytokine storms and lowers duckling mortality.

Development and efficacy evaluation of a novel water-in-oil-in-water adjuvant for an inactivated foot-and-mouth disease vaccine

To develop a novel water-in-oil-in-water (W/O/W) adjuvant and evaluate the effect on foot-and-mouth disease (FMD) inactivated vaccine, in this study, we prepared the novel nano-emulsion adjuvant based on QS-21 (BEA) which is composed of the mixture of mineral oil Marcol52, surfactant Tween80, oleate polyoxyethylene ether ester, polyoxyethylene palmitic acid ester and span80, cosurfactant polyethylene glycol and QS-21. The two-step emulsification method formed the W/O/W nano-emulsion with two films and three-phase structures. The effective particle diameter of the BEA was about 184 nm, and it has good thermal stability. Then, BEA was emulsified as an adjuvant to prepare for the inactivated FMDV vaccine, and BALB/c mice and pigs were immunized to evaluate its safety and immunization effect. The results showed that the inactivated BEA-FMDV vaccine significantly increased BALB/c mice and pigs' antibodies and cytokine IFN-γ in serum. Meanwhile, the pig-neutralizing antibodies were higher than control group. Safety tests found no symptoms of FMD or significant toxic reactions. After 28 days of immunization, the protection rate can reach 93.3%. The BEA vaccine had good stability at 4 °C, no stratification after 180 days, and the content of 146S in the vaccine did not decrease. In conclusion, the BEA prepared in this study is suitable for FMDV inactivated vaccine and is an effective adjuvant.

Triple-Emulsion-Based Antibubbles: A Step Forward in Fabricating Novel Multi-Drug Delivery Systems

Developing carriers capable of efficiently transporting both hydrophilic and lipophilic payloads is a captivating focus within the pharmaceutical and drug delivery research domain. Antibubbles, constituting an innovative encapsulation system designed for drug delivery purposes, have garnered scientific interest thanks to their distinctive water-in-air-in-water (W1/A/W2) structure. However, in contrast to their precursor, i.e., nanoparticle-stabilized W1/O/W2 double emulsion, traditional antibubbles lack the ability to accommodate a lipophilic payload, as the intermediary (volatile) oil layer of the emulsion is replaced by air during the antibubble fabrication process. Therefore, here, we report the fabrication of triple-emulsion-based antibubbles (O1/W1/A/W2), in which the inner aqueous phase was loaded with a nanoemulsion stabilized by various proteins, including whey, soy, or pea protein isolates. As model drugs, we employed the dyes Nile red in the oil phase and methylene blue in the aqueous phase. The produced antibubbles were characterized regarding their size distribution, entrapment efficiency, and stability. The produced antibubbles demonstrated substantial entrapment efficiencies for both lipophilic (ranging from 80% to 90%) and hydrophilic (ranging from 70% to 82%) components while also exhibiting an appreciable degree of stability during an extended rehydration period of two weeks. The observed variations among different antibubble variants were primarily attributed to differences in protein concentration rather than the type of protein used.

Investigation and Evaluation of the Transdermal Delivery of Ibuprofen in Various Characterized Nano-Drug Delivery Systems

The aim was to assess the suitability of three nano-based transdermal drug delivery systems containing ibuprofen: a nano-emulsion, a nano-emulgel, and a colloidal suspension with ibuprofen-loaded nanoparticles. Understanding the transdermal delivery of ibuprofen using nano-based drug delivery systems can lead to more effective pain relief and improved patient compliance. Characterization tests assessed the suitability of the developed drug delivery systems. Membrane release and skin diffusion studies, along with tape stripping, were performed to determine drug release and skin permeation of ibuprofen. In vitro cytotoxicity studies on HaCaT cells were conducted using MTT and neutral red assays to evaluate the safety of the developed drug delivery systems. Characterization studies confirmed stable drug delivery systems with ideal properties for transdermal delivery. Membrane release studies demonstrated the successful release of ibuprofen. In vitro skin diffusion experiments and tape stripping, detecting ibuprofen in the receptor phase, stratum corneum-epidermis, and epidermis-dermis, indicating successful transdermal and topical delivery. The in vitro cytotoxicity studies observed only minor cytotoxic effects on HaCaT cells, indicating the safety of the developed drug delivery systems. The investigation demonstrated promising results for the transdermal delivery of ibuprofen using the developed drug delivery systems, which contributes to valuable insights that may lead to improved pain management strategies.

Characterization of polysaccharide from Lonicera japonica Thunb leaves and its application in nano-emulsion

The polysaccharides in honeysuckle leaves (PHL) were separated and characterized for the first time. The nano-emulsion stabilized by PHL and whey protein isolate (WPI) were also fabricated based on the ultrasonic method. The results indicated that PHL was mainly composed of glucose (47.40 mol%), galactose (19.21 mol%) and arabinose (20.21 mol%) with the weight-average molecular weight of 137.97 ± 4.31 kDa. The emulsifier concentration, WPI-to-PHL ratio, ultrasound power and ultrasound time had significant influence on the droplet size of PHL-WPI nano-emulsion. The optimal preparation conditions were determined as following: emulsifier concentration, 1.7%; WPI/PHL ratio, 3:1; ultrasonic power, 700 W; ultrasonic time, 7 min. Under the above conditions, the median diameter of the obtained nano-emulsion was 317.70 ± 5.26 nm, close to the predicted value of 320.20 nm. The protective effect of PHL-WPI emulsion on β-carotene against UV irradiation was superior to that of WPI emulsion. Our results can provide reference for the development of honeysuckle leaves.

Characterization of a Dihydromyricetin/α-Lactoalbumin Covalent Complex and Its Application in Nano-emulsions

A dihydromyricetin (DMY)/α-lactoalbumin (α-La) covalent complex was prepared and characterized, and its application in nano-emulsions was also evaluated in this study. The results suggested that the covalent complex could be obtained using the alkaline method. The UV and IR spectra confirmed the formation of the covalent complex, and the amount of DMY added was positively correlated with the total phenol content of the complex. The complex had an outstanding 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-radical-scavenging ability, reducing power and α-glucosidase inhibitory activity, which were positively related to its total phenol content. The complex could be used as an emulsifier to stabilize the β-carotene-loaded nano-emulsion. The stability and β-carotene-protective capacity of the nano-emulsion stabilized by the complex were also positively related to the total phenol content of the complex, being higher than those of the nano-emulsion developed using α-La. Our results provide a reference for the construction of a new food delivery system and extend the applications of α-La and DMY in foods.

The synergy of tea tree oil nano-emulsion and antibiotics against multidrug-resistant bacteria

AIMS

We determined the synergistic effects of tea tree essential oil nano-emulsion (nanoTTO) and antibiotics against multidrug-resistant (MDR) bacteria in vitro and in vivo. Then, the underlying mechanism of action of nanoTTO was investigated.

METHODS AND RESULTS

Minimum inhibitory concentrations and fractional inhibitory concentration index (FICI) were determined. The transepithelial electrical resistance (TEER) and the expression of tight junction (TJ) protein of IPEC-J2 cells were measured to determine the in vitro efficacy of nanoTTO in combination with antibiotics. A mouse intestinal infection model evaluated the in vivo synergistic efficacy. Proteome, adhesion assays, quantitative real-time PCR, and scanning electron microscopy were used to explore the underlying mechanisms. Results showed that nanoTTO was synergistic (FICI ≤ 0.5) or partial synergistic (0.5 < FICI < 1) with antibiotics against MDR Gram-positive and Gram-negative bacteria strains. Moreover, combinations increased the TEER values and the TJ protein expression of IPEC-J2 cells infected with MDR Escherichia coli. The in vivo study showed that the combination of nanoTTO and amoxicillin improved the relative weight gain and maintained the structural integrity of intestinal barriers. Proteome showed that type 1 fimbriae d-mannose specific adhesin of E. coli was downregulated by nanoTTO. Then, nanoTTO reduced bacterial adhesion and invasion and inhibited the mRNA expression of fimC, fimG, and fliC, and disrupted bacterial membranes.

Aphicidal Activity and Phytotoxicity of Citrus sinensis Essential-Oil-Based Nano-Insecticide

Due to its high polyphagy, Aphis gossypii is considered a key pest of many crops, and it can feed on hundreds of plant species belonging to the families Cucurbitaceae, Malvaceae, Solanaceae, Rutaceae, and Asteraceae. The control of this pest mainly relies on synthetic insecticides whose adverse effects on the environment and human health are encouraging researchers to explore innovative, alternative solutions. In this scenario, essential oils (EOs) could play a key role in the development of ecofriendly pesticides. In this study, the development of a citrus peel EO-based nano-formulation and its biological activity against A. gossypii both in the laboratory and field were described and evaluated. The phytotoxicity towards citrus plants was also assessed. The developed nano-insecticide highlighted good aphicidal activity both in the laboratory and field trials, even at moderate EO concentrations. However, the highest tested concentrations (4 and 6% of active ingredient) revealed phytotoxic effects on the photosynthetic apparatus; the side effects need to be carefully accounted for to successfully apply this control tool in field conditions.

Boosting Tadalafil Bioavailability via Sono-Assisted Nano-Emulsion-Based Oral Jellies: Box-Behnken Optimization and Assessment

Tadalafil (TAD) is a poorly soluble, phosphodiesterase inhibitor used to treat erectile dysfunction. The primary goal of this project was to prepare nano-emulsions using ultrasonic technology to address TAD bioavailability concerns. The Box−Behnken design was employed to find prominent correlations between factors impacting the sono-emulsification process. The emulsifier concentration, amplitude level, and ultrasonication time were the independent factors, whereas the average droplet size (ADS) and polydispersity index (PDI) were designated as the response variables. TAD-loaded nano-emulsions (93−289 nm) were generated and the emulsifier concentration showed a crucial role in directing emulsion droplet size. The model desirability function was utilized to optimize a nano-emulsion with a small ADS (99.67 ± 7.55 nm) and PDI (0.45 ± 0.04) by adjusting the emulsifiers concentration, amplitude level, and ultrasonication time at 9.85%, 33%, 49 s, respectively. The optimized nano-emulsions did not demonstrate any precipitation or phase separation after stability stress tests. TAD jellies were formulated based on the optimized nano-emulsion and subjected to in vitro evaluation for physical characteristics; TAD content, pH, spreadability, viscosity, syneresis, and taste-masking ability. An optimized nano-emulsion-based jelly (NEJ) formulation showed more than 96% drug dissolution in 30 min relative to 14% for the unprocessed TAD. In vivo assessment of NEJ in experimental rats demonstrated a significant enhancement (p < 0.05) of TAD bioavailability with an AUC0−24h of 2045 ± 70.2 vs. 259.9 ± 17.7 ng·h·mL−1 for the unprocessed TAD. Storage stability results revealed that NEJ remained stable with unremarkable changes in properties for 3 months. Overall, NEJ can be regarded as a successful therapeutic option for TAD administration with immediate-release properties and improved bioavailability.

Development and Efficacy Evaluation of a Novel Nano-Emulsion Adjuvant for a Foot-and-Mouth Disease Virus-like Particles Vaccine Based on Squalane

The successful development of foot-and-mouth disease virus-like particles (FMD-VLPs) has opened a new direction for researching a novel subunit vaccine for foot-and-mouth disease (FMD). Therefore, it is urgent to develop an adjuvant that is highly effective and safe to facilitate a better immune response to be pair with the FMD-VLP vaccine. In this research, we prepared a new nano-emulsion adjuvant based on squalane (SNA) containing CpG using the pseudo-ternary phase diagram method and the phase transformation method. The SNA consisted of Span85, Tween60, squalane, polyethene glycol-400 (PEG400) and CpG aqueous solution. The average particle diameter of the SNA was about 95 nm, and it exhibited good resistance to centrifugation, thermal stability, and biocompatibility. Then, SNA was emulsified as an adjuvant to prepare foot-and-mouth disease virus-like particles vaccine, BALB/c mice and guinea pigs were immunized, and we evaluated the immunization effect. The immunization results in mice showed that the SNA-VLPs vaccine significantly increased specific antibody levels in mice within 4 weeks, including higher levels of IgG1 and IgG2a. In addition, it increased the levels of IFN-γ and IL-1β in the immune serum of mice. Meanwhile, guinea pig-specific and neutralizing antibodies were considerably increased within 4 weeks when SNA was used as an adjuvant, thereby facilitating the proliferation of splenic lymphocytes. More importantly, in guinea pigs immunized with one dose of SNA-VLPs, challenged with FMDV 28 days after immunization, the protection rate can reach 83.3%, which is as high as in the ISA-206 control group. In conclusion, the novel squalane nano-emulsion adjuvant is an effective adjuvant for the FMD-VLPs vaccine, indicating a promising adjuvant for the future development of a novel FMD-VLPs vaccine.

Eco-friendly 'ochratoxin A' control in stored licorice roots - quality assurance perspective

According to toxicity data, ochratoxin A (OTA) is the second most important mycotoxin and is produced by Aspergillus and Penicillium. As a natural antifungal agent, clove essential oil (CEO) is a substance generally recognised as safe (GRAS) and shows strong activity against fungal pathogens. Here, we aimed to investigate the control efficacy of CEO in nano-emulsions (CEN) against OTA production in licorice roots and rhizomes during storage. The experiments were performed under simulated conditions of all four seasons (i.e. Spring, Summer, Autumn and Winter). Relative humidity (RH) and temperature were simulated in desiccators along with various salt solutions in incubators. Fresh licorice roots were immersed in CEN at various concentrations (150, 300, 600, 1200 and 2400 µl/l). Before utilising the nano-emulsions, we measured their polydispersity index and mean droplet size by the dynamic light scattering (DLS) technique. Also, the chemical composition of the CEO was determined using GC and GC-MS analyses. Sampling was carried out to monitor OTA once every five days. The samples were dried immediately and analysed by high-performance liquid chromatography (HPLC). Results showed that various concentrations of CEN inhibited the growth of fungi and OTA production. The most effective CEN concentrations were 1200 and 2400 µl/l, which reduced OTA production to 19 and 20 ppb under Winter and Autumn conditions, respectively. These results suggest an effective eco-friendly method for the storage of licorice to reduce postharvest fungal decay.

Nano Filling Effect of Nonmeat Protein Emulsion on the Rheological Property of Myofibrillar Protein Gel

Incorporation of vegetable oils through pre-emulsification has received notable attention for delivering polyunsaturated fatty acids to emulsified-type meat products. The two important influencing factors of the rheological property of composite myofibrillar protein (MP) gel are emulsion droplet size and active or inactive interaction between interface and meat proteins. Incorporation of nonmeat protein emulsion (2% protein (w/w), egg-white protein isolate (EPI), porcine plasma protein (PPP), or sodium caseinate (SC)) with different droplet sizes (nano or macro) to a model of 2% MP gel was investigated in this research. The results of drop size measurement showed that 15,000 psi homogenizing could decrease the diameter of emulsion drop from macro- to nanoscale in the range of 324.4−734.5 nm. Active fillers (PPP and EPI emulsions) with nanodroplet size did not influence the viscosity of emulsion-filled composite cold sols but caused positive filling effects on the MP gel matrix after heating, as evidenced by the density microstructure. PPP and EPI nano-emulsion-filled composite MP had a significant high storage modulus enforcement effect, which reached nearly eight times those of other treatments (p < 0.05). Similarly, the results of thermal scanning rheology and a large-deformation mechanical test showed that PPP and EPI emulsions with nanoscale droplets, other than macroscale, had the highest gel strength of heat-induced emulsion-filled composite MP gel (p < 0.05). Overall, these findings will be helpful for selecting the correct pre-emulsified protein and designing the textural properties of foods.

Efficiency of Red Onion Peel Extract Capsules on Obesity and Blood Sugar

BACKGROUND AND OBJECTIVE

Red onions are one of the most consumed vegetable crops in Egypt, their peel is rich in antioxidants that reduce the risk of diabetes and weight is lost. The study aimed to extract bioactive compounds present in Egyptian Red Onion Peels Waste (ROPE), increasing their efficiency and protecting them using nano-encapsulation as new emerging technology.

MATERIALS AND METHODS

Extraction of the bioactive compounds in the Egyptian red onion peels was carried out to study their antioxidant activity before and after nano-emulsions and micro-capsules, their physical and morphological characteristics with their different nano-forms and their application in sponge cake products. The biological evaluation was also studied using rats and statistical analysis.

RESULTS

The results showed that the ethanol extracts high content of bioactive compounds compared to water extract and that the use of nano-technique as a new emerging technology in form of nano-emulsion using sodium alginate with diameter size between 8.3-13.6 nm. Results also indicated that there was an improvement in the efficiency of antioxidant activity at high-temperature degrees during baking, with a melting point of up to 223.64°C, with an improvement in the blood sugar levels of diabetic rats and a significant decrease in body weight.

CONCLUSION

Nano treatments had a protective effect on liver, safety towards kidneys, lowering blood sugar, improving the efficiency comparing to the other samples and were more acceptable to the consumer.

Water-in-Oil Nano-Emulsions Prepared by Spontaneous Emulsification: New Insights on the Formulation Process

Nano-emulsions consist of stable suspensions of nano-scaled droplets that have huge loading capacities and are formulated with safe compounds. For these reasons, a large number of studies have described the potential uses of nano-emulsions, focusing on various aspects such as formulation processes, loading capabilities, and surface modifications. These studies typically concern direct nano-emulsions (i.e., oil-in-water), whereas studies on reverse nano-emulsions (i.e., water-in-oil) remain anecdotal. However, reverse nano-emulsion technology is very promising (e.g., as an alternative to liposome technology) for the development of drug delivery systems that encapsulate hydrophilic compounds within double droplets. The spontaneous emulsification process has the added advantages of optimization of the energetic yield, potential for industrial scale-up, improved loading capabilities, and preservation of fragile compounds targeted for encapsulation. In this study, we propose a detailed investigation of the processes and formulation parameters involved in the spontaneous nano-emulsification that produces water-in-oil nano-emulsions. The following details were addressed: (i) the order of mixing of the different compounds (method A and method B), (ii) mixing rates, (iii) amount of surfactants, (iv) type and mixture of surfactants, (v) amount of dispersed phase, and (vi) influence of the nature of the oil. The results emphasized the effects of the formulation parameters (e.g., the volume fraction of the dispersed phase, nature or concentration of surfactant, or nature of the oil) on the nature and properties of the nano-emulsions formed.

The Anti-Inflammatory Effect of a γ-Lactone Isolated from Ostrich Oil of Struthio camelus (Ratite) and Its Formulated Nano-Emulsion in Formalin-Induced Paw Edema

The ostrich oil of Struthio camelus (Ratite) found uses in folk medicine as an anti-inflammatory in eczema and contact dermatitis. The anti-inflammatory effect of a γ-lactone (5-hexyl-3H-furan-2-one) isolated from ostrich oil and its formulated nano-emulsion in formalin-induced paw edema was investigated in this study. Ostrich oil was saponified using a standard procedure; the aqueous residue was fractionated, purified, and characterized as γ-lactone (5-hexyl-3H-furan-2-one) through the interpretation of IR, NMR, and MS analyses. The γ-lactone was formulated as nano-emulsion using methylcellulose (MC) for oral solubilized form. The γ-lactone methylcellulose nanoparticles (γ-lactone-MC-NPs) were characterized for their size, shape, and encapsulation efficiency with a uniform size of 300 nm and 59.9% drug content. The γ-lactone was applied topically, while the formulated nanoparticles (NPs) were administered orally to rats. A non-steroidal anti-inflammatory drug (diclofenac gel) was used as a reference drug for topical use and ibuprofen suspension for oral administration. Edema was measured using the plethysmograph method. Both γ-lactone and γ-lactone-MC-NPs showed reduction of formalin-induced paw edema in rats and proved to be better than the reference drugs; diclofenac gel and ibuprofen emulsion. Histological examination of the skin tissue revealed increased skin thickness with subepidermal edema and mixed inflammatory cellular infiltration, which were significantly reduced by the γ-lactone compared to the positive control (p-value = 0.00013). Diuretic and toxicity studies of oral γ-lactone-MC-NPs were performed. No diuretic activity was observed. However, lethargy, drowsiness, and refusal to feeding observed may limit its oral administration.

A Nano-Emulsion Platform Functionalized with a Fully Human scFv-Fc Antibody for Atheroma Targeting: Towards a Theranostic Approach to Atherosclerosis

Atherosclerosis is at the onset of the cardiovascular diseases that are among the leading causes of death worldwide. Currently, high-risk plaques, also called vulnerable atheromatous plaques, remain often undiagnosed until the occurrence of severe complications, such as stroke or myocardial infarction. Molecular imaging agents that target high-risk atheromatous lesions could greatly improve the diagnosis of atherosclerosis by identifying sites of high disease activity. Moreover, a "theranostic approach" that combines molecular imaging agents (for diagnosis) and therapeutic molecules would be of great value for the local management of atheromatous plaques. The aim of this study was to develop and characterize an innovative theranostic tool for atherosclerosis. We engineered oil-in-water nano-emulsions (NEs) loaded with superparamagnetic iron oxide (SPIO) nanoparticles for magnetic resonance imaging (MRI) purposes. Dynamic MRI showed that NE-SPIO nanoparticles decorated with a polyethylene glycol (PEG) layer reduced their liver uptake and extended their half-life. Next, the NE-SPIO-PEG formulation was functionalized with a fully human scFv-Fc antibody (P3) recognizing galectin 3, an atherosclerosis biomarker. The P3-functionalized formulation targeted atheromatous plaques, as demonstrated in an immunohistochemistry analyses of mouse aorta and human artery sections and in an Apoe^-/- mouse model of atherosclerosis. Moreover, the formulation was loaded with SPIO nanoparticles and/or alpha-tocopherol to be used as a theranostic tool for atherosclerosis imaging (SPIO) and for delivery of drugs that reduce oxidation (here, alpha-tocopherol) in atheromatous plaques. This study paves the way to non-invasive targeted imaging of atherosclerosis and synergistic therapeutic applications.

Non-Invasive Delivery of Nano-Emulsified Sesame Oil-Extract of Turmeric Attenuates Lung Inflammation

Turmeric, the golden Indian spice, and the edible oil of sesame seeds are the essential ingredients of Indian food created by ancestors and established the belief of the curative effect of food for many generations. Considering the anti-inflammatory effects of turmeric, we formulated a nano-emulsion of turmeric infused in edible sesame oil, with a globule size of 200–250 nm using high-energy microfluidization. The product with a zeta potential of −11.5 mV showed spherical globules when imaged for scanning and transmission electron microscopy. We explored the anti-inflammatory potential of this edible nano-emulsion in lung inflammation. The lungs are the internal organ most vulnerable to infection, injury, and rapid inflammation from the external environment because of their constant exposure to pollutants, pathogenic microorganisms, and viruses. We evaluated the nano-emulsion for efficacy in ovalbumin-induced lung injury in mice with an oral treatment for two weeks. The therapeutic effect of nano-emulsion of the sesame oil-extract of turmeric was evident from biochemical analysis of bronchoalveolar lavage fluid, lung histopathology, and flow cytometric analysis. The developed nano-emulsion significantly reduced the inflammation and damage to the alveolar network in ovalbumin-injured mice. Significant reduction in the levels of neutrophils and inflammatory cytokines like IL-4, IL-6, and IL-13 in bronchoalveolar lavage fluid was observed in the nano-emulsion-treated group. Leukotriene B4 and IgE were also significantly altered in the treated group, thus suggesting the suitability of the formulation for the treatment of allergy and other inflammatory conditions. The nano-emulsification process potentiated the immunoregulatory effect of turmeric, as observed from the elevated levels of the natural anti-inflammatory cytokine, IL-10. The dietary constituents-based nano-emulsion of spice turmeric helped in scavenging the free radicals in the injured lungs, thus modulating the inflammation pathway. This easily scalable formulation technology approach can therefore serve as a potential noninvasive and safe treatment modality for reducing lung inflammation in lung injury cases.

Development and in vitro Evaluation of Gastro-protective Aceclofenac-loaded Self-emulsifying Drug Delivery System

AIM

Chronic use of oral nonsteroidal anti-inflammatory drugs (NSAIDs) is commonly associated with gastric irritation and gastric ulceration. Therefore, the aim of study was to develop a novel oral drug delivery system with minimum gastric effects and improved dissolution rate for aceclofenac (ACF), a model BCS class-II drug.

METHODS

Self-emulsifying drug delivery systems (SEDDS) were formulated to increase the solubility and ultimately the oral bioavailability of ACF. Oleic acid was used as an oil phase, Tween 80 (T80) and Kolliphor EL (KEL) were used as surfactants, whereas, polyethylene glycol 400 (PEG 400) and propylene glycol (PG) were employed as co-surfactants. Optimized formulations (F1, F2, F3 and F4) were analyzed for droplet size, poly dispersity index (PDI), cell viability studies, in vitro dissolution in both simulated gastric fluid and simulated intestinal fluid, ex vivo permeation studies and thermodynamic stability.

RESULTS

The optimized formulations showed mean droplet sizes in the range of 111.3 ± 3.2 nm and 470.9 ± 12.52 nm, PDI from 244.6 nm to 389.4 ± 6.51 and zeta-potential from -33 ± 4.86 mV to -38.5 ± 5.15 mV. Cell viability studies support the safety profile of all formulations for oral administration. The in vitro dissolution studies and ex vivo permeation analysis revealed significantly improved drug release ranging from 95.68 ± 0.02% to 98.15 ± 0.71% when compared with control. The thermodynamic stability studies confirmed that all formulations remain active and stable for a longer period.

CONCLUSION

In conclusion, development of oral SEDDS might be a promising tool to improve the dissolution of BCS class-II drugs along with significantly reduced exposure to gastric mucosa.

Cremophor EL Nano-Emulsion Monomerizes Chlorophyll a in Water Medium

In this paper, the application of a non-ionic detergent Cremophor EL for monomerization of chlorophyll a in an aqueous medium is studied. The spectrophotometric properties of chlorophyll a encapsulated into the Cremophor EL nano-emulsion system were characterized by electronic absorption, steady-state and time-resolved fluorescence as well as circular dichroism spectroscopy. The results have shown that chlorophyll a dissolves more efficiently in the aqueous medium containing low-level Cremophor (5 wt%) than at an ethanolic solution even in the concentration of 10⁻⁴ M. The molecular organization of the chlorophyll a in the Cremophor EL nano-micelles was also investigated by means of Raman spectroscopy. The spectral changes in the frequency of the C=O stretching group were used to distinguish the aggregation state of chlorophyll. It was revealed that chlorophyll a exists dominantly in the monomeric form in the Cremophor EL aqueous solution. The promising aspect of the use of Cremophor EL nano-emulsion as a delivery system is to maintain stable chlorophyll monomer in an aqueous medium. It would open the potential for a new, practical application of chlorophyll a in medicine, as a dietary supplement or studies on molecular organization of chlorophyll a in the well-defined artificial system.

Effects of edible coating containing nano-emulsion of Aloe vera and eugenol on the physicochemical properties of shrimp during cold storage

BACKGROUND

Shrimp is nowadays recognized as a rich source of proteins and omega-3 fatty acids. Edible nano-emulsion coatings containing eugenol, as an antioxidant agent, and Aloe vera, as a functional compound, were prepared for the storage of pink shrimp over 7 days at 277 K. Samples of the nano-emulsion were prepared under ultrasonication using 0, 10 and 20 g L^-1 of Aloe vera as well as 0, 15 and 30 mL L^-1 of eugenol along with Tween 80.

RESULTS

Results indicated that the low pH of Aloe vera reduced that of the nano-emulsions while the particle size and turbidity increased with increasing Aloe vera concentration. Moreover, both colour and antioxidant activity of the nano-emulsions were significantly affected by eugenol and Aloe vera concentrations (p < 0.05). Increasing eugenol concentration led to increased nano-emulsion pickup but to reduced lightness. Higher concentrations of Aloe vera significantly (p < 0.05) decreased drip loss, cooking loss, pH rise and oxidation rates but enhanced hardness in the shrimp samples.

CONCLUSIONS

The best results were recorded for the nano-emulsion coating containing 30 mL L^-1 of eugenol and 20 g L^-1 of Aloe vera. The nano-emulsion was successfully able to upgrade shrimp quality over 7 days of cold storage. © 2019 Society of Chemical Industry.

Use of Resveratrol Self-Emulsifying Systems in T/C28a2 Cell Line as Beneficial Effectors in Cellular Uptake and Protection Against Oxidative Stress-Mediated Death

Osteoarthritis (OA) is the most prevalent rheumatic disease in the world. Although its etiology is still unknown, one of the key processes in OA progression and development is oxidative stress. In this context, resveratrol, a well-known anti-oxidant from the stilbene family, could be of particular interest in future OA therapeutic strategies. However, currently, because of its low bioavailability, use of resveratrol in human health is very limited. In this study, we tested two resveratrol self-emulsifying systems previously developed in our laboratory in order to determine if they could improve cellular uptake of resveratrol in a human immortalized chondrocytic cell line (T/C28a2) and enhance protection against oxidative stress. Our results showed that resveratrol self-emulsifying systems were able first to increase cellular tolerance towards resveratrol, and thus decrease resveratrol intrinsic cellular toxicity, allowing the use of higher concentrations, second, to increase resveratrol uptake in membrane and intracellular fractions, and finally, to improve protection against oxidative stress-mediated death in human immortalized chondrocytic cell line T/C28a2. These data suggest that new formulations of resveratrol could be considered as potential beneficial effectors in future OA treatments.

Nose-to-Brain Delivery of Antiviral Drugs: A Way to Overcome Their Active Efflux?

Although several viruses can easily infect the central nervous system (CNS), antiviral drugs often show dramatic difficulties in penetrating the brain from the bloodstream since they are substrates of active efflux transporters (AETs). These transporters, located in the physiological barriers between blood and the CNS and in macrophage membranes, are able to recognize their substrates and actively efflux them into the bloodstream. The active transporters currently known to efflux antiviral drugs are P-glycoprotein (ABCB1 or P-gp or MDR1), multidrug resistance-associated proteins (ABCC1 or MRP1, ABCC4 or MRP4, ABCC5 or MRP5), and breast cancer resistance protein (ABCG2 or BCRP). Inhibitors of AETs may be considered, but their co-administration causes serious unwanted effects. Nasal administration of antiviral drugs is therefore proposed in order to overcome the aforementioned problems, but innovative devices, formulations (thermoreversible gels, polymeric micro- and nano-particles, solid lipid microparticles, nanoemulsions), absorption enhancers (chitosan, papaverine), and mucoadhesive agents (chitosan, polyvinilpyrrolidone) are required in order to selectively target the antiviral drugs and, possibly, the AET inhibitors in the CNS. Moreover, several prodrugs of antiretroviral agents can inhibit or elude the AET systems, appearing as interesting substrates for innovative nasal formulations able to target anti-Human Immunodeficiency Virus (HIV) agents into macrophages of the CNS, which are one of the most important HIV Sanctuaries of the body.

Biodistribution and Toxicity of X-Ray Iodinated Contrast Agent in Nano-emulsions in Function of Their Size

PURPOSE

This study aimed to investigate the impact of the size of X-ray iodinated contrast agent in nano-emulsions, on their toxicity and fate in vivo.

METHODS

A new compound, triiodobenzoate cholecalciferol, was synthetized, formulated as nano-emulsions, and followed after i.v. administration in mice by X-ray imaging (micro computed tomography). Physicochemical characterization and process optimization allowed identifying a good compromise between X-ray contrasting properties, monodispersity and stability. This also allowed selecting two formulations with different sizes, hydrodynamic diameters of 55 and 100 nm, but exactly the same composition. In vitro experiments were performed on two cell lines, namely hepatocytes (BNL-CL2) and macrophages (RAW264.7).

RESULTS

Cell viability studies, cell uptake observations by confocal microscopy, and uptake quantification by fluorimetry, disclosed clear differences between two formulations, as well as between two types of cell lines. After i.v. injection of the two iodinated nano-emulsions in mice, CT scans provided the quantification of the pharmacokinetics and biodistributions. We finally showed that the size in the nano-emulsions has not a real impact on the pharmacokinetics and biodistributions, but has a strong influence on their toxicity, corroborating the in vitro results.

CONCLUSIONS

This study shows that the size of the nanocarrier significantly matters, likely due to highly different interactions with cells and tissues. Graphical Abstract A study on the effect of the size of cholecciferol nano-emulsions, on their in vivo becoming, through X-ray imaging modality.

Radiosensitization of Hs-766T Pancreatic Tumor Xenografts in Mice Dosed with Dodecafluoropentane Nano-Emulsion-Preliminary Findings

Tumor hypoxia is an important mediator of radiation therapy resistance. We conducted a study to investigate whether an oxygen therapeutic based upon dodecafluoropentane (DDFP) nano-emulsion (NVX-108) could increase tumor PO2 in hypoxic tumors and improve radiation response. Pancreatic (Hs-766T) tumor xenografts were grown in the flanks of 29 SCID mice. Direct tumor PO2 measurements were performed in 9 mice treated with 0.3, 0.45 and 0.6 cc/kg NVX-108 (2% w/vol DDFP) in order to assess the dose dependent increase in tumor PO2. Twenty mice were randomized into 3 groups including control (no treatment), carbogen breathing treated with 12 Gy radiation, and carbogen breathing treated with 12 Gy radiation and NVX-108 (0.6 cc/kg NVX-108 administered as 30 minute IV infusion at time of radiation). Tumor volume was monitored to assess treatment efficacy. Results showed that tumor PO2 increased in NVX-108 treated mice up to 400% with the greatest effect seen at the highest dose of 0.6 cc/kg. Tumor growth was significantly reduced in both treatment groups relative to controls (p < 0.0001). The combination of carbogen, radiation, and NVX-108 demonstrated a 2-fold reduction in average tumor volume compared to carbogen plus radiation treatment (p = 0.01). Further study of NVX-108 as a radiation sensitizer is warranted.

Biodistribution of X-ray iodinated contrast agent in nano-emulsions is controlled by the chemical nature of the oily core

In this study, we investigated the role of the chemical nature of the oil droplet core of nano-emulsions used as contrast agents for X-ray imaging on their pharmacokinetics and biodistribution. To this end, we formulated PEGylated nano-emulsions with two iodinated oils (i.e., iodinated monoglyceride and iodinated castor oil) and compared them with another iodinated nano-emulsion based on iodinated vitamin E. By using dynamic light scattering and transmission electron microscopy, the three iodinated nano-emulsions were found to exhibit comparable morphologies, size, and surface composition. Furthermore, they were shown to be endowed with very high iodine concentration, which leads to stronger X-ray attenuation properties as compared to the commercial iodinated nano-emulsion Fenestra VC. The three nano-emulsions were i.v. administered in mice and monitored by microcomputed tomography (micro-CT). They showed high contrast enhancement in blood with similar half-life around 6 h but very different accumulation sites. While iodinated monoglycerides exhibited low accumulation in liver and spleen, high accumulation in spleen was observed for iodinated castor oil and in liver for vitamin E. These data clearly highlighted the important role of the oil composition of the nano-emulsion core to obtain strong X-ray contrast enhancement in specific targets such as liver, spleen, or only blood. These differences in biodistribution were partly attributed to differences in the uptake of the nanodroplets by the macrophages in vitro. Another key feature of these nano-emulsions is their long half-elimination time (several weeks), which offers sufficient retention for micro-CT imaging. This work paves the way for the design of nanoparticulate contrast agents for X-ray imaging of selected organs.

Counterion-enhanced cyanine dye loading into lipid nano-droplets for single-particle tracking in zebrafish

Superior brightness of fluorescent nanoparticles places them far ahead of the classical fluorescent dyes in the field of biological imaging. However, for in vivo applications, inorganic nanoparticles, such as quantum dots, are limited due to the lack of biodegradability. Nano-emulsions encapsulating high concentrations of organic dyes are an attractive alternative, but classical fluorescent dyes are inconvenient due to their poor solubility in the oil and their tendency to form non-fluorescent aggregates. This problem was solved here for a cationic cyanine dye (DiI) by substituting its perchlorate counterion for a bulky and hydrophobic tetraphenylborate. This new dye salt, due to its exceptional oil solubility, could be loaded at 8 wt% concentration into nano-droplets of controlled size in the range 30-90 nm. Our 90 nm droplets, which contained >10,000 cyanine molecules, were >100-fold brighter than quantum dots. This extreme brightness allowed, for the first time, single-particle tracking in the blood flow of live zebrafish embryo, revealing both the slow and fast phases of the cardiac cycle. These nano-droplets showed minimal cytotoxicity in cell culture and in the zebrafish embryo. The concept of counterion-based dye loading provides a new effective route to ultra-bright lipid nanoparticles, which enables tracking single particles in live animals, a new dimension of in vivo imaging.