Insights into the release mechanisms of antioxidants from nanoemulsion droplets

The therapeutic effects of antioxidant-loaded nanoemulsion can be often optimized by controlling the release rate in human body. Release kinetic models can be used to predict the release profile of antioxidant compounds and allow identification of key parameters that affect the release rate. It is known that one of the critical aspects in establishing a reliable release kinetic model is to understand the underlying release mechanisms. Presently, the underlying release mechanisms of antioxidants from nanoemulsion droplets are not yet fully understood. In this context, this review scrutinized the current formulation strategies to encapsulate antioxidant compounds and provide an outlook into the future of this research area by elucidating possible release mechanisms of antioxidant compounds from nanoemulsion system.

The safety of nanomaterials in food production and packaging

Nanotechnology involves developing, characterising, and applying structures ranging in size from 1 to 100 nm. As a key advanced technology, it has contributed to a substantial impact across engineering, medicine, agriculture and food. With regards to their application in food, nanomaterials posses the ability to lead the quantitative and qualitative development of high-quality, healthier, and safer foods by outperforming traditional food processing technologies for increasing shelf life and preventing contaminations. Although rapid progress has been made in nanotechnology in food products, the toxicity of nanoparticles and nanomaterials is not very well known. As a result, nanomaterials are potentially toxic, therefore, considering the constantly increasing employment in food science, they need to be further characterised, and their use must be better regulated. We may face a crisis of nanotoxicity if the molecular mechanisms by which nanoparticles and nanomaterials interact with food and within living organisms is not fully understood. Food safety can be guaranteed only if we are thoroughly aware of nanomaterial properties and potential toxicity. Therefore, it is urgently necessary to have in the food sector a regulatory system capable of managing nanofood risks and nanotechnology, considering the health effects of food processing techniques based on nanotechnology. This present review discusses the impact and role nanotechnology play in food science. The specific application of Nanomaterials in food science, their advantages and disadvantages, the potential risk for human health and the analysis to detect nanocomponents are also highlighted.

Vegetable oil-based nanoemulsions for the preservation of muscle foods: A systematic review and meta-analysis

This systematic review and meta-analysis quantified the effects of various vegetable oil-based nanoemulsion (NE) formulations on muscle foods' microbial and chemical quality by estimating the weighted overall response ratio (R*). Treatment of muscle foods with NE formulations reduced the growth rates of total mesophilic bacteria, total psychrophilic bacteria, lactic acid bacteria, and Enterobacteriaceae by 26.2% (R*=0.738), 19% (R*=0.810), 44.7% (R*=0.553), and 31.8% (R*=0.682) during the storage period, respectively. Moreover, the NE formulations retarded the increasing rates of volatile basic-nitrogen content, lipid and protein oxidation, and lipid hydrolysis by 41.4% (R*=0.586), 34% (R*=0.660), 55% (R*=0.450), and 37.1% (R*=0.629), respectively. The NE formulations prepared from safflower, olive, canola, and sunflower oil were more effective than the other vegetable oils to control microbial growth and slow down chemical changes in muscle foods. The combination of nanoemulsions (NEs) and essential oils (EOs) was more efficient than NEs to preserve muscle foods. Packaging NE-treated muscle foods under anaerobic conditions provided better control of microbial growth and chemical changes than packaging under aerobic conditions. Consequently, a combination of vegetable oil-based NEs and EOs followed by anaerobic packaging is the most effective treatment to improve the quality of muscle foods.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2057415 .

Contribution of Nanoscience Research in Antioxidants Delivery Used in Nutricosmetic Sector

Nanoscience applications in the food and cosmetic industry offer many potential benefits for consumers and society. Nanotechnologies permit the manipulation of matter at the nanoscale level, resulting in new properties and characteristics useful in food and cosmetic production, processing, packaging, and storage. Nanotechnology protects sensitive bioactive compounds, improves their bioavailability and water solubility, guarantees their release at a site of action, avoids contact with other constituents, and masks unpleasant taste. Biopolymeric nanoparticles, nanofibers, nanoemulsions, nanocapsules, and colloids are delivery systems used to produce food supplements and cosmetics. There are no barriers to nanoscience applications in food supplements and cosmetic industries, although the toxicity of nano-sized delivery systems is not clear. The physicochemical and toxicological characterization of nanoscale delivery systems used by the nutricosmeceutic industry is reviewed in this work.

Study on the Effects of Biologically Active Amino Acids on the Micellization of Anionic Surfactant Sodium Dodecyl Sulfate (SDS) at Different Temperatures

The micellar properties of the anionic surfactant, sodium dodecyl sulfate (SDS) are modified by the biologically active amino acids. Amino acids (AAs) have experienced a variety of interactions and are proposed to influence SDS micelles due to their nominated hydrophobic interactions. The present study determines the critical micellar concentration (CMC) of SDS in aqueous solutions as well as in amino aqueous solutions. Three amino acids (glutamic acid, histidine, and tryptophan) are considered here. The conductometric measurements were carried out using a wide range of SDS concentrations at different temperatures. Surface tension experiments have also been applied to estimate many surface parameters including surface excess concentration (Γmax), surface occupied area per surfactant molecule (Amin), surface tension at CMC (γcmc), surface pressure at CMC (Πcmc) and Gibbs free energy of adsorption (∆Gads°), enthalpy ∆Hm° and the critical packing parameter (CPP). Interestingly, CMC values of SDS in water and in aqueous amino acids estimated by the surface tension method are comparable with the corresponding values obtained by the conductance method. The thermodynamic parameters of SDS micellization were also evaluated in both presence and absence of AAs. The additives of AAs work to reduce the CMC values, as well as the SDS thermodynamic parameters. This reduction is highly dependent on the hydrophobicity of the AA side chain. Negative values of ∆Gm°, ∆Hm° elucidate that micellization of SDS in the presence of amino acids is thermodynamically spontaneous and exothermic. The outcomes here might be utilized for pharmaceutical applications to stabilize proteins and inhibit protein aggregation.

Composite Membrane Dressings System with Metallic Nanoparticles as an Antibacterial Factor in Wound Healing

Wound management is the burning problem of modern medicine, significantly burdening developed countries’ healthcare systems. In recent years, it has become clear that the achievements of nanotechnology have introduced a new quality in wound healing. The application of nanomaterials in wound dressing significantly improves their properties and promotes the healing of injuries. Therefore, this review paper presents the subjectively selected nanomaterials used in wound dressings, including the metallic nanoparticles (NPs), and refers to the aspects of their application as antimicrobial factors. The literature review was supplemented with the results of our team’s research on the elements of multifunctional new-generation dressings containing nanoparticles. The wound healing multiple molecular pathways, mediating cell types, and affecting agents are discussed herein. Moreover, the categorization of wound dressings is presented. Additionally, some materials and membrane constructs applied in wound dressings are described. Finally, bacterial participation in wound healing and the mechanism of the antibacterial function of nanoparticles are considered. Membranes involving NPs as the bacteriostatic factors for improving wound healing of skin and bones, including our experimental findings, are discussed in the paper. In addition, some studies of our team concerning the selected bacterial strains’ interaction with material involving different metallic NPs, such as AuNPs, AgNPs, Fe₃O₄NPs, and CuNPs, are presented. Furthermore, nanoparticles’ influence on selected eukaryotic cells is mentioned. The ideal, universal wound dressing still has not been obtained; thus, a new generation of products have been developed, represented by the nanocomposite materials with antibacterial, anti-inflammatory properties that can influence the wound-healing process.

Nanomedicine of Plant Origin for the Treatment of Metabolic Disorders

Metabolic disorders are major clinical challenges of health that are progressing globally. A concurrence of metabolic disorders such as obesity, insulin resistance, atherogenic dyslipidemia, and systematic hypertension leads to metabolic syndrome. Over the past years, the metabolic syndrome leads to a five- and two-fold rise in diabetes mellitus type II and cardiovascular diseases. Natural products specifically plant extracts have insulin-sensitizing, anti-inflammatory, and antioxidant properties and are also considered as an alternative option due to few adverse effects. Nanotechnology is one of the promising strategies, which improves the effectiveness of treatment and limits side effects. This review mainly focuses on plant extract-based nanosystems in the management of the metabolic syndrome. Numerous nano-drug delivery systems, i.e., liposomes, hydrogel nanocomposites, nanoemulsions, micelles, solid lipid, and core–shell nanoparticles, have been designed using plant extracts. It has been found that most of the nano-formulations successfully reduced oxidative stress, insulin resistance, chronic inflammation, and lipid profile in in vitro and in vivo studies as plant extracts interfere with the pathways of metabolic syndrome. Thus, these novel plant-based nanosystems could act as a promising candidate for clinical applications.

Biocontrol Potential of Essential Oils in Organic Horticulture Systems: From Farm to Fork

In recent decades, increasing attention has been paid to food safety and organic horticulture. Thus, people are looking for natural products to manage plant diseases, pests, and weeds. Essential oils (EOs) or EO-based products are potentially promising candidates for biocontrol agents due to their safe, bioactive, biodegradable, ecologically, and economically viable properties. Born of necessity or commercial interest to satisfy market demand for natural products, this emerging technology is highly anticipated, but its application has been limited without the benefit of a thorough analysis of the scientific evidence on efficacy, scope, and mechanism of action. This review covers the uses of EOs as broad-spectrum biocontrol agents in both preharvest and postharvest systems. The known functions of EOs in suppressing fungi, bacteria, viruses, pests, and weeds are briefly summarized. Related results and possible modes of action from recent research are listed. The weaknesses of applying EOs are also discussed, such as high volatility and low stability, low water solubility, strong influence on organoleptic properties, and phytotoxic effects. Therefore, EO formulations and methods of incorporation to enhance the strengths and compensate for the shortages are outlined. This review also concludes with research directions needed to better understand and fully evaluate EOs and provides an outlook on the prospects for future applications of EOs in organic horticulture production.

Fabrication and Evaluation of Quercetin Nanoemulsion: A Delivery System with Improved Bioavailability and Therapeutic Efficacy in Diabetes Mellitus

The current study was intended to fabricate and evaluate ultrasonically assisted quercetin nanoemulsion (Que-NE) for improved bioavailability and therapeutic effectiveness against diabetes mellitus in rats. Ethyl oleate, Tween 20, and Labrasol were chosen as oil, surfactant, and cosurfactant, respectively. Box–Behnken design (BBD) was employed to study the influence of process variables such as % surfactant and cosurfactant mixture (Smix) (5 to 7%), % amplitude (20–30%) and sonication time (2.5–7.5 min) on droplet size, polydispersibility index (PDI), and % entrapment efficiency (%EE) were studied. The optimization predicted that 9% Smix at 25% amplitude for 2.5 min would produce Que-NE with a droplet size of 125.51 nm, 0.215 PDI, and 87.04% EE. Moreover, the optimized Que-NE exhibited appreciable droplet size and PDI when stored at 5, 30, and 40 °C for 45 days. Also, the morphological characterization by transmission electron microscope (TEM) indicated the spherical shape of the optimized nanoemulsion. Furthermore, the Que-NE compared to pure quercetin exhibited superior release and enhanced oral bioavailability. The streptozocin-induced antidiabetic study in rats revealed that the Que-NE had remarkable protective and therapeutic properties in managing body weight, blood glucose level, lipid profile, and tissue injury markers, alongside the structure of pancreatic β-cells and hepatocytes being protected. Thus, the developed Que-NE could be of potential use as a substitute strategy for diabetes.

Chitosan nanoemulsion: Gleam into the futuristic approach for preserving the quality of muscle foods

Trend for consumption of healthy meat without synthetic additives is blooming globally and has attracted the interest of consumers and research sphere to look for enhancement of quality and safety of food. Chitosan is multi-functional marine biopolymer with several befitting properties such as non-toxicity, ease of modification, antimicrobial activity, biodegradability and bio-compatibility, making it suitable for use in meat based food systems, which are highly prone to putrescence due to availability of high level protein, micronutrients and moisture. Bioactive components from plant extracts on account of their natural lineage are exquisite determinants for meat preservation in association with chitosan to replace synthetic molecules, which are considered to evince toxicological effects. Nanoemulsions are viable systems for integrating a myriad of active constituents framed by microfluidization, high-pressure homogenization, ultra-sonication, phase inversion (PIC and PIT) and spontaneous-emulsification with benefits of droplet size reduction, improved solubility, stability and their biological activity. This article summarizes the most important information on formulation, fabrication and advancements in chitosan-based nanoemulsions highlighting their potential benefit for applications in the muscle food system. Supervising the all-around executions of chitosan nanoemulsions for various food systems, the current review has been framed to lay down understandings regarding improvements made in the production and functionality of chitosan nanoemulsions for quality retention of meat products. Furthermore, it highlights the novel trends in chitosan-nanoemulsions application in meat based food systems from a preservation and shelf-life prolongation perspective.

Essential Oil Nanoemulsion as Eco-Friendly and Safe Preservative: Bioefficacy Against Microbial Food Deterioration and Toxin Secretion, Mode of Action, and Future Opportunities

Microbes are the biggest shareholder for the quantitative and qualitative deterioration of food commodities at different stages of production, transportation, and storage, along with the secretion of toxic secondary metabolites. Indiscriminate application of synthetic preservatives may develop resistance in microbial strains and associated complications in human health with broad-spectrum environmental non-sustainability. The application of essential oils (EOs) as a natural antimicrobial and their efficacy for the preservation of foods has been of present interest and growing consumer demand in the current generation. However, the loss in bioactivity of EOs from fluctuating environmental conditions is a major limitation during their practical application, which could be overcome by encapsulating them in a suitable biodegradable and biocompatible polymer matrix with enhancement to their efficacy and stability. Among different nanoencapsulated systems, nanoemulsions effectively contribute to the practical applications of EOs by expanding their dispersibility and foster their controlled delivery in food systems. In line with the above background, this review aims to present the practical application of nanoemulsions (a) by addressing their direct and indirect (EO nanoemulsion coating leading to active packaging) consistent support in a real food system, (b) biochemical actions related to antimicrobial mechanisms, (c) effectiveness of nanoemulsion as bio-nanosensor with large scale practical applicability, (d) critical evaluation of toxicity, safety, and regulatory issues, and (e) market demand of nanoemulsion in pharmaceuticals and nutraceuticals along with the current challenges and future opportunities.

A review study on new aspects of biodemulsifiers: Production, features and their application in wastewater treatment

The effluent produced in refineries is in the form of an oil/water emulsion that must be treated. These emulsions are often stable and a suitable method must be used to separate the oil from the emulsion. Recently, biosurfactants or biodemulsifiers have received much attention to reduce the interfacial tension between two liquids. Biodemulsifiers are produced by microorganisms and have several benefits over chemical demulsifiers such as low-toxic, biodegradability, eco-friendly and easy synthesis. They can eliminate two phases by changing the interfacial forces between the water and oil molecules. Biosurfactants are categorized based on the molecular weight of their compounds (low or high molecular weight). Sophorolipids, lipopeptides rhamnolipids, trehalolipids, glycolipid, lipoproteins, lichenysin, surfactin, and polymeric biosurfactants are several types of biosurfactants, which are produced by bacteria or fungi. This review study provides a deep evaluation of biosurfactants in the demulsification process. To this end, different types of biosurfactants, the synthesis method of various biosurfactants using various microorganisms, features of biosurfactants, and the role of biodemulsifiers in the demulsification process are thoroughly discussed. Also, the impact of various efficient factors like pH, microorganism type, temperature, the oil content in the emulsion, and gravity on biodemulsificaion was studied. Finally, the mechanism of the demulsification process was discussed. According to previous studies, rhamnolipid biodemulsifier showed the highest biodemulsification efficiency (100%) in the removal of oil from an emulsion.

Advanced approaches for improving bioavailability and controlled release of anthocyanins

Anthocyanins are a group of phytochemicals responsible for the purple or red color of plants. Additionally, they are recognized to have health promoting functions including anti-cardiovascular, anti-thrombotic, anti-diabetic, antimicrobial, neuroprotective, and visual protective effect as well as anti-cancer activities. Thus, consumption of anthocyanin supplement or anthocyanin-rich foods has been recommended to prevent the risk of development of chronic diseases. However, the low stability and bioavailability of anthocyanins limit the efficacy and distribution of anthocyanins in human body. Thus, strategies to achieve target site-local delivery with good bioavailability and controlled release rate are necessary. This review introduced and discussed the latest advanced techniques of designing lipid-based, polysaccharide-based and protein-based complexes, nano-encapsulation and exosome to overcome the limitation of anthocyanins. The improved bioavailability and controlled release of anthocyanins have great significance for gastrointestinal tract absorption, transepithelial transportation and cellular uptake. The techniques of applying different biocompatible materials and modifying the solubility of anthocyanins complex could achieve target site-local delivery with negligible degradation and good bioavailability in human body.

In Silico Drug Screening Based Development of Novel Formulations for Onychomycosis Management

Onychomycosis is a prominent fungal infection that causes discoloration, thickening, and mutilation leading to the separation of the nail from the nail bed. Treatment modalities for onychomycosis may include oral, topical, or combination therapy with antifungals and at times may require chemical or surgical intervention. The burden of side effects of antifungals is enormous, and therefore using molecular docking-based drug selection in context with the target keratin protein would ensure better disease management. Ciclopirox, Amorolfine HCl, Efinaconazole, Tioconazole, and Tavaborole were submitted for assessment, revealing that Amorolfine HCl is the best fit. Consequently, two formulations (Nail lacquer and nanoemulgel) were developed from Amorolfine HCl to validate the in silico screening outcomes. The formulations were further fortified with over-the-counter ingredients vis-a-vis with vitamin E in nail lacquer and undecylenic acid in nanoemulgel for their prominent roles in improving nail health. Both the formulations were systematically designed, optimized, and characterized. Amorolfine HCl containing nanoemulgel (NEG) was developed using undecylenic acid as an oil phase and thioglycolic acid as a penetration enhancer. The quality parameters evaluated were particle size, the zeta potential for nanoemulsion (NE) (78.04 ± 4.724 nm and −0.7mV, respectively), in vitro cumulative drug release (96.74% for NE and 88.54% for NEG), and transungual permeation (about 73.49% for NEG and 54.81% for NE). Nail lacquer was evaluated for the drying time, non-volatile content, and blush test. In vitro cumulative drug release of the developed nail lacquer and comparator marketed formulations were around 81.5% and 75%, respectively. Similarly, the transungual drug permeation was 6.32 μg/cm² and 5.89 μg/cm², respectively, in 24 h. The in silico guided preparation of both formulations containing Amorolfine HCl and over the counter ingredients is amenable for therapeutic use against onychomycosis and will be evaluated in the in vivo model.

Comprehensive study of α-terpineol-loaded oil-in-water (O/W) nanoemulsion: interfacial property, formulation, physical and chemical stability

In this study, the interfacial ability of α-terpineol (α-TOH) was reported, followed by its trapping into oil-in-water (O/W) nanoemulsion as active-ingredient and the long-term observation of this nanosystem influenced by the storage-time (410-days) and temperature (5, 25, 50 °C). The results indicated that the α-TOH can reduce the interfacial tension on the liquid-liquid interface (ΔG°m = -1.81 KJ mol-1; surface density = 8.19 × 10-6 mol m-2; polar head group area = 20.29 Å2), in the absence or presence of surfactant. The O/W nanoemulsion loaded with a high amount of α-TOH (90 mg mL-1; 9α-TOH-NE) into the oil phase was successfully formulated. Among the physical parameters, the mean droplet diameter (MDD) showed a great thermal dependence influenced by the storage-temperature, where the Ostwald ripening (OR) was identified as the main destabilizing phenomena that was taking place on 9α-TOH-NE at 5 and 25 °C along with time. Despite of the physical instability, the integrity of both nanoemulsion at 5 °C and 25 °C was fully preserved up to 410th day, displaying a homogeneous and comparable appearance by visual observation. On contrary, a non-thermal dependence was found for chemical stability, where over 88% of the initial amount of the α-TOH nanoemulsified remained in both 9α-TOH-NE at 5 and 25 °C, up to 410th day. Beyond the key data reported for α-TOH, the importance of this research relies on the long-term tracking of a nanostructured system which can be useful for scientific community as a model for a robust evaluation of nanoemulsion loaded with flavor oils.

A Systematic Review on Nanoencapsulation Natural Antimicrobials in Foods: In Vitro versus In Situ Evaluation, Mechanisms of Action and Implications on Physical-Chemical Quality

Natural antimicrobials (NA) have stood out in the last decade due to the growing demand for reducing chemical preservatives in food. Once solubility, stability, and changes in sensory attributes could limit their applications in foods, several studies were published suggesting micro-/nanoencapsulation to overcome such challenges. Thus, for our systematic review the Science Direct, Web of Science, Scopus, and Pub Med databases were chosen to recover papers published from 2010 to 2020. After reviewing all titles/abstracts and keywords for the full-text papers, key data were extracted and synthesized. The systematic review proposed to compare the antimicrobial efficacy between nanoencapsulated NA (nNA) and its free form in vitro and in situ studies, since although in vitro studies are often used in studies, they present characteristics and properties that are different from those found in foods; providing a comprehensive understanding of primary mechanisms of action of the nNA in foods; and analyzing the effects on quality parameters of foods. Essential oils and nanoemulsions (10.9-100 nm) have received significant attention and showed higher antimicrobial efficacy without sensory impairments compared to free NA. Regarding nNA mechanisms: (i) nanoencapsulation provides a slow-prolonged release to promote antimicrobial action over time, and (ii) prevents interactions with food constituents that in turn impair antimicrobial action. Besides in vitro antifungal and antibacterial, nNA also demonstrated antioxidant activity-potential to shelf life extension in food. However, of the studies involving nanoencapsulated natural antimicrobials used in this review, little attention was placed on proximate composition, sensory, and rheological evaluation. We encourage further in situ studies once data differ from in vitro assay, suggesting food matrix greatly influences NA mechanisms.

Nanoemulsions: Formulation, characterization, biological fate, and potential role against COVID-19 and other viral outbreaks

Viral diseases are emerging as global threats. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), that causes coronavirus disease (COVID-19), has severe global impacts. Safety, dosage, and potency of vaccines recently approved for emergency use against SARS-CoV-2 need further evaluation. There is still no effective treatment against COVID-19; therefore, safe, and effective vaccines or therapeutics against SARS-CoV-2 are urgently needed. Oil-in-water nanoemulsions (O/W NEs) are emerging as sophisticated, protective, and therapeutic platforms. Encapsulation capacity, which offers better drug pharmacokinetics, coupled with the tunable surfaces present NEs as promising tools for pharmaceutical applications. The challenges facing drug discovery, and the advancements of NEs in drug delivery demonstrate the potential of NEs against evolving diseases, like COVID-19. Here we summarize current COVID-19 knowledge and discuss the composition, stability, preparation, characterization, and biological fate of O/W NEs. We also provide insights into NE structural-functional properties that may contribute to therapeutic or preventative solutions against COVID-19.

Biodegradable Amphoteric Surfactants in Titration-Ultrasound Formulation of Oil-in-Water Nanoemulsions: Rational Design, Development, and Kinetic Stability

Amphoteric amphiphilic compounds, due to their unique properties, may represent a group of safe and biocompatible surface-active agents for effective colloidal stabilization of nanoformulations. For this reason, the aim of this work was to develop and characterize the oil-in-water nanoemulsions based on two betaine-derived surfactants with high biodegradability, i.e., cocamidopropyl betaine and coco-betaine. In the first step, we investigated ternary phase diagrams of surfactant-oil-water systems containing different weight ratios of surfactant and oil, as the betaine-type surfactant entity (S), linoleic acid, or oleic acid as the oil phase (O), and the aqueous phase (W) using the titration-ultrasound approach. All the received nanoemulsion systems were then characterized upon droplets size (dynamic light scattering), surface charge (electrophoretic light scattering), and morphology (transmission electron as well as atomic force microscopy). Thermal and spinning tests revealed the most stable compositions, which were subjected to further kinetic stability analysis, including turbidimetric evaluation. Finally, the backscattering profiles revealed the most promising candidate with a size <200 nm for potential delivery of active agents in the future cosmetic, pharmaceutical, and biomedical applications.

Coupling Ifosfamide to nanoemulsion-based clove oil enhances its toxicity on malignant breast cancer and cervical cancer cells

The anticancer effects of chemotherapeutic agents may be accentuated, and their side effects minimized by combining them with essential oils in nanocarrier systems. This study aimed to incorporate ifosfamide (IF) into nanoemulsion-based clove oil (IF-CLV). The nano-emulsion (NE) formulas were characterized with Zetasizer. The cytotoxicity of the formulated NEs against cervical (HeLa) and breast (MCF-7) cancer cell lines was determined using MTT assay, light microscopy, and DAPI staining. The z – average diameters of NE-CLV and IF-CLV were 63.1±1.00 and 89.4±2.64 nm, while Zeta potential values were – 4.39±0.4 and – 11.65±1.1mV, respectively. Cytotoxicity studies revealed that relative to free IF, NE-CLV and IF-CLV were highly toxic on HeLa and MCF-7cells, in a dose-dependent manner. The half-maximal inhibitory concentration (IC50) values of NE-CLV against HeLa and MCF-7 have decreased 38 and 27 folds, while the corresponding IC50 values of IF-CLV have decreased 57 and 35 folds, respectively. These results suggest that the incorporation of IF into NE-based clove oil produces potent therapeutic effects against cancer cell lines.

Dermal Drug Delivery of Phytochemicals with Phenolic Structure via Lipid-Based Nanotechnologies

Phenolic compounds are a large, heterogeneous group of secondary metabolites found in various plants and herbal substances. From the perspective of dermatology, the most important benefits for human health are their pharmacological effects on oxidation processes, inflammation, vascular pathology, immune response, precancerous and oncological lesions or formations, and microbial growth. Because the nature of phenolic compounds is designed to fit the phytochemical needs of plants and not the biopharmaceutical requirements for a specific route of delivery (dermal or other), their utilization in cutaneous formulations sets challenges to drug development. These are encountered often due to insufficient water solubility, high molecular weight and low permeation and/or high reactivity (inherent for the set of representatives) and subsequent chemical/photochemical instability and ionizability. The inclusion of phenolic phytochemicals in lipid-based nanocarriers (such as nanoemulsions, liposomes and solid lipid nanoparticles) is so far recognized as a strategic physico-chemical approach to improve their in situ stability and introduction to the skin barriers, with a view to enhance bioavailability and therapeutic potency. This current review is focused on recent advances and achievements in this area.

Development of Chrysin Loaded Oil-in-Water Nanoemulsion for Improving Bioaccessibility

Chrysin (5,7-dihydroxyflavone) is a remarkable flavonoid exhibiting many health-promoting activities, such as antioxidant, anti-inflammatory, and anti-Alzheimer's disease (AD). Nevertheless, chrysin has been addressed regarding its limited applications, due to low bioaccessibility. Therefore, to improve chrysin bioaccessibility, a colloidal delivery system involving nanoemulsion was developed as chrysin nanoemulsion (chrysin-NE) using an oil-in-water system. Our results show that chrysin can be loaded by approximately 174.21 µg/g nanoemulsion (100.29 ± 0.53% w/w) when medium chain triglyceride (MCT) oil was used as an oil phase. The nanocolloidal size, polydispersity index, and surface charge of chrysin-NE were approximately 161 nm, 0.21, and -32 mV, respectively. These properties were stable for at least five weeks at room temperature. Furthermore, in vitro chrysin bioactivities regarding antioxidant and anti-AD were maintained as pure chrysin, suggesting that multistep formulation could not affect chrysin properties. Interestingly, the developed chrysin-NE was more tolerant of gastrointestinal digestion and significantly absorbed by the human intestinal cells (Caco-2) than pure chrysin. These findings demonstrate that the encapsulation of chrysin using oil-in-water nanoemulsion could enhance the bioaccessibility of chrysin, which might be subsequently applied to food and nutraceutical industries.

Prevalence of antimicrobial-resistant Streptococcus species among respiratory patients and meat products, and antibacterial effects of oregano oil nanoemulsion

Background and Aim: Antimicrobial-resistant Streptococcus species causes several diseases in humans with infection recurrence in some cases. Handling of food under unhygienic conditions resulted in transmission of pathogens to food leading to risks for consumers' health. This work studies the possible role of humans in transmission of human pathogens to food products. In this study, we focused on the presence of antimicrobial resistance Streptococcus pyogenes, Streptococcus mitis, and Streptococcus pneumoniae found in respiratory patients and in some meat products. We detected the risk factors for patient's infection and examined the antibacterial effect of oregano oil nanoemulsion (ONE) at different concentrations against the multi-drug resistance strains of streptococci. Materials and Methods: Microbiological culture and polymerase chain reaction were used to identify S. pyogenes, S. mitis, and S. pneumoniae in 120 throat swab samples and 200 meat products. The disk diffusion method was used for investigating the prevalence of resistance against 10 antimicrobials that are commonly used in the treatment of humans and animals. ONE at four concentrations (0.5%, 1.0%, 2.0%, and 3.0%) with an average particle size of 45.4 nm was identified using transmission electron microscopy. The effect of ONE on Streptococcus species isolates was examined using the well diffusion method. Risk factors for human infection were detected using statistical analysis. Results: S. pyogenes, S. mitis, and S. pneumoniae were detected in 14 (11.7%), 9 (7.5%), and 7 (5.8%), respectively, of 120 throat swabs of patients. These bacteria were also detected in 11 (5.5%), 8 (4%), and 6 (3%), respectively, of 200 meat products samples. Beef luncheon had the highest infection rate for the three species of streptococci. The majority of these isolates showed resistance to antimicrobials such as tetracycline and amoxicillin/clavulanic acid. ONE had an inhibitory effect on the growth of S. pyogenes, S. mitis, and S. pneumoniae, and its effect was significantly increased at a high concentration (3%), with a mean inhibition zone of 36.45±0.302 mm. Very young and old patients, those with chronic diseases, and those exposed to the infection several times were most susceptible to infection. Conclusion: ONE may be used as a therapeutic agent at safe and specific doses, and also in the food industry, to prevent the spoilage of food and protect human health.

Microbial surfactants in nanotechnology: recent trends and applications

The interest in nano-sized materials to develop novel products has increased exponentially in the last decade, together with the search for green methods for their synthesis. An alternative to contribute to a more sustainable approach is the use of microbial-derived molecules to assist nanomaterial synthesis. In this sense, biosurfactants (BSs) have emerged as eco-friendly substitutes in nano-sized materials preparation. The inherent amphiphilic and self-assembly character of BSs associated with their low eco-toxicity, biodegradability, biocompatibility, structural diversity, biological activity, and production from renewable resources are potential advantages over chemically-derived surfactants. In nanotechnology, these versatile molecules play multiple roles. In nanoparticle (NP) synthesis, they act as capping and reducing agents and they also provide self-assembly structures to encapsulation, functionalization, or templates and act as emulsifiers in nanoemulsions. Moreover, BSs can also play as active compounds owing to their intrinsic biological properties. This review presents the recent trends in the development of BS-based nanostructures and their biomedical and environmental applications. Fundamental aspects regarding their antimicrobial and anticancer activities are also discussed.

Innovative Delivery Systems Loaded with Plant Bioactive Ingredients: Formulation Approaches and Applications

Plants constitute a rich source of diverse classes of valuable phytochemicals (e.g., phenolic acids, flavonoids, carotenoids, alkaloids) with proven biological activity (e.g., antioxidant, anti-inflammatory, antimicrobial, etc.). However, factors such as low stability, poor solubility and bioavailability limit their food, cosmetics and pharmaceutical applications. In this regard, a wide range of delivery systems have been developed to increase the stability of plant-derived bioactive compounds upon processing, storage or under gastrointestinal digestion conditions, to enhance their solubility, to mask undesirable flavors as well as to efficiently deliver them to the target tissues where they can exert their biological activity and promote human health. In the present review, the latest advances regarding the design of innovative delivery systems for pure plant bioactive compounds, extracts or essential oils, in order to overcome the above-mentioned challenges, are presented. Moreover, a broad spectrum of applications along with future trends are critically discussed.

A Critical Review of the Use of Surfactant-Coated Nanoparticles in Nanomedicine and Food Nanotechnology

Surfactants, whose existence has been recognized as early as 2800 BC, have had a long history with the development of human civilization. With the rapid development of nanotechnology in the latter half of the 20th century, breakthroughs in nanomedicine and food nanotechnology using nanoparticles have been remarkable, and new applications have been developed. The technology of surfactant-coated nanoparticles, which provides new functions to nanoparticles for use in the fields of nanomedicine and food nanotechnology, is attracting a lot of attention in the fields of basic research and industry. This review systematically describes these "surfactant-coated nanoparticles" through various sections in order: 1) surfactants, 2) surfactant-coated nanoparticles, application of surfactant-coated nanoparticles to 3) nanomedicine, and 4) food nanotechnology. Furthermore, current progress and problems of the technology using surfactant-coated nanoparticles through recent research reports have been discussed.

Recent Advances on Nanoparticle Based Strategies for Improving Carotenoid Stability and Biological Activity

Carotenoids are natural pigments widely used in food industries due to their health-promoting properties. However, the presence of long-chain conjugated double bonds are responsible for chemical instability, poor water solubility, low bioavailability and high susceptibility to oxidation. The application of a nanoencapsulation technique has thus become a vital means to enhance stability of carotenoids under physiological conditions due to their small particle size, high aqueous solubility and improved bioavailability. This review intends to overview the advances in preparation, characterization, biocompatibility and application of nanocarotenoids reported in research/review papers published in peer-reviewed journals over the last five years. More specifically, nanocarotenoids were prepared from both carotenoid extracts and standards by employing various preparation techniques to yield different nanostructures including nanoemulsions, nanoliposomes, polymeric/biopolymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid nanoparticles, supercritical fluid-based nanoparticles and metal/metal oxide nanoparticles. Stability studies involved evaluation of physical stability and/or chemical stability under different storage conditions and heating temperatures for varied lengths of time, while the release behavior and bioaccessibility were determined by various in vitro digestion and absorption models as well as bioavailability through elucidating pharmacokinetics in an animal model. Moreover, application of nanocarotenoids for various biological applications including antioxidant, anticancer, antibacterial, antiaging, cosmetics, diabetic wound healing and hepatic steatosis were summarized.

Application of Advanced Emulsion Technology in the Food Industry: A Review and Critical Evaluation

The food industry is one of the major users of emulsion technology, as many food products exist in an emulsified form, including many dressings, sauces, spreads, dips, creams, and beverages. Recently, there has been an interest in improving the healthiness, sustainability, and safety of foods in an attempt to address some of the negative effects associated with the modern food supply, such as rising chronic diseases, environmental damage, and food safety concerns. Advanced emulsion technologies can be used to address many of these concerns. In this review article, recent studies on the development and utilization of these advanced technologies are critically assessed, including nanoemulsions, high internal phase emulsions (HIPEs), Pickering emulsions, multilayer emulsions, solid lipid nanoparticles (SLNs), multiple emulsions, and emulgels. A brief description of each type of emulsion is given, then their formation and properties are described, and finally their potential applications in the food industry are presented. Special emphasis is given to the utilization of these advanced technologies for the delivery of bioactive compounds.

Physicochemical characterization of a DMPC-based nanoemulsion for dry eye and compatibility test with soft contact lenses in vitro

INTRODUCTION

The use of contact lenses (CL) is often associated with hallmark symptoms of dry eye disease (DED) such as red eye and dryness. Even though lipid-based artificial tears are already marketed for DED, there is little evidence that supports their use while wearing soft CL.

METHODS

An oil in water (O/W) nanoemulsion was formulated with a highly-stable oily phase composed of castor oil and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). Physicochemical characterization of the DMPC-based nanoemulsion (DMPC-NE) was performed using the Zetasizer Nano ZSP, and its long-term stability was evaluated over 24 months; in addition, the in vitro cytotoxicity of DMPC-NE was determined by Neutral Red Uptake (NRU) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Finally, the physical compatibility of the DMPC-NE with soft CL was tested by measuring the power, diameter, thickness and UV transmittance of two different types of CL.

RESULTS

DMPC-NE had a mean particle size of 86.48 ± 4.22 nm, a polydispersity index of 0.22 ± 0.01 and a zeta potential of -33.23 ± 0.93 mV that remained with no changes after 24 months. DMPC-NE formulation, free of preservatives, showed no cytotoxicity and it was compatible with the physical properties of FDA-class II and -class IV CL.

CONCLUSION

DMPC-NE is a highly stable formulation for dry eye that is safe to be used while wearing soft CL.

An overview of nanoemulsion characterization via atomic force microscopy

Nanoemulsion-based systems are widely applied in food industries for protecting active ingredients against oxidation and degradation and controlling the release rate of active core ingredients under particular conditions. Visualizing the interface morphology and measuring the interfacial interaction forces of nanoemulsion droplets are essential to tailor and design intelligent nanoemulsion-based systems. Atomic force microscopy (AFM) is being established as an important technique for interface characterization, due to its unique advantages over traditional imaging and surface force-determining approaches. However, there is a gap in knowledge about the applicability of AFM in characterizing the droplet interface properties of nanoemulsions. This review aims to describe the fundamentals of the AFM technique and nanoemulsions, mainly focusing on the recent use of AFM to investigate nanoemulsion properties. In addition, by reviewing interfacial studies on emulsions in general, perspectives for the further development of AFM to study nanoemulsions are also discussed.

Fabrication of nanoparticles for bone regeneration: new insight into applications of nanoemulsion technology

Introducing synthetic bone substitutes into the clinic was a major breakthrough in the regenerative medicine of bone. Despite many advantages of currently available bone implant materials such as biocompatiblity and osteoconductivity, they still suffer from relatively poor bioactivity, osteoinductivity and osteointegration. These properties can be effectively enhanced by functionalization of implant materials with nanoparticles such as osteoinductive hydroxyapatite nanocrystals, resembling inorganic part of the bone, or bioactive polymer nanoparticles providing sustained delivery of pro-osteogenic agents directly at implantation site. One of the most widespread techniques for fabrication of nanoparticles for bone regeneration applications is nanoemulsification. It allows manufacturing of nanoscale particles (<100 nm) that are injectable, 3D-printable, offer high surface-area-to-volume-ratio and minimal mass transport limitations. Nanoparticles obtained by this technique are of particular interest for biomedical engineering due to fabrication procedures requiring low surfactant concentrations, which translates into reduced risk of surfactant-related in vivo adverse effects and improved biocompatibility of the product. This review discusses nanoemulsion technology and its current uses in manufacturing of nanoparticles for bone regeneration applications. In the first section, we introduce basic concepts of nanoemulsification including nanoemulsion formation, properties and preparation methods. In the next sections, we focus on applications of nanoemulsions in fabrication of nanoparticles used for delivery of drugs/biomolecules facilitating osteogenesis and functionalization of bone implants with special emphasis on biomimetic hydroxyapatite nanoparticles, synthetic polymer nanoparticles loaded with bioactive compounds and bone-targeting nanoparticles. We also highlight key challenges in formulation of nanoparticles via nanoemulsification and outline potential further improvements in this field.

Studies on the Effect of Oil and Surfactant on the Formation of Alginate-Based O/W Lidocaine Nanocarriers Using Nanoemulsion Template

The application of various nanocarrier systems was widely explored in the field of pharmaceuticals to achieve better drug encapsulation and delivery. The aim of this study was to encapsulate lidocaine in alginate-based o/w nanocarriers based on the type of oil (i.e., solid or liquid), using a nanoemulsion template prepared by ultrasound-assisted phase inversion temperature (PIT) approach. The nanoemulsion template was initially prepared by dissolving lidocaine in the oil phase and surfactant and alginate in the aqueous phase, and keeping the PIT at around 85 °C, accompanied by gradual water dilution at 25 °C, to initiate the formation of nanoparticles (o/w) with the aid of low frequency ultrasound. The composition and concentration of the oil phase had a major impact on the particle size and led to an increase in the size of the droplet. The lipids that showed a higher drug solubility also showed higher particle size. On the other hand, increasing the concentration of surfactant decreases the size of the droplet before the concentration of the surfactant exceeds the limit, after which the size of the particle increases due to the aggregates that could be produced from the excess surfactant. The method used produced nanoemulsions that maintained nano-sized droplets < 50 nm, over long-term storage. Our findings are important for the design of nanocarrier systems for the encapsulation of lipophilic molecules.