Search Results (1,546)

Cod liver oil is a rich source of polyunsaturated fatty acids (PUFAs) but is highly susceptible to oxidative degradation, limiting its use in topical formulations. This study aimed to develop stable cod liver oil nanoemulsions for topical application and to evaluated the influence of surfactant ratio (lecithin/PEG-15 hydroxystearate: 2.5:1 and 1:1, w/w), emulsification method (ultrasonication or high-pressure homogenization), and vitamin E acetate supplementation on their physicochemical properties and oxidative stability. Eight nanoemulsions were characterized in terms of droplet size, polydispersity, ζ-potential, vitamin E acetate encapsulation efficiency, oxidative stability, film-forming capacity and cytocompatibility. Among the investigated formulations, F4 (2.5:1 lecithin/PEG-15 hydroxystearate, high-pressure homogenization, with vitamin E acetate) exhibited the most favorable characteristics, including a mean droplet size of 67.95 nm, ζ-potential of −63.12 mV and vitamin E acetate encapsulation efficiency of 32.59%. The formulation demonstrated good physicochemical stability under thermal, mechanical and photostability testing, improved oxidative stability, transient film-forming behavior with an initial occlusive effect, and no cytotoxicity toward human dermal fibroblasts. These findings indicate that nanoemulsion performance depends on the combined influence of formulation composition and processing conditions, with F4 representing a promising topical carrier for cod liver oil intended for interaction with the stratum corneum. Full article

Sophorolipids (SLs) produced from Starmerella bombicola using four different secondary substrates such as refined, bleached, and deodorized palm olein (RBD PO), RBD palm kernel olein (RBD PKO), RBD coconut olein (RBD CO) and fatty acid methyl ester (FAME) waste are reported. Their interfacial characteristics at medium-chain triglyceride (MCT) oil-water interface and ability to form nano/submicron emulsions were studied. The effects of SLs from different sources, SL concentrations and blend ratios of SLs and soybean lecithin on characteristics of emulsions produced by ultrasonication were examined. Initially, emulsion formed using SLs coded (from F2 to F5) showed large droplets (d₃₂ > 1000 nm) and poor stability. They were then blended with soybean lecithin at a ratio of 3:1 to produce emulsions coded F6 to F9 with smaller droplets (d₃₂ < 400 nm) and great stability over a range of temperatures (from 40 °C to 90 °C) and pH values (from 3 to 9). However, highly acidic (pH 2) and low ionic strength (1 mM NaCl) processing caused the separation of the emulsions. These emulsions also displayed potential antimicrobial activities towards Bacillus cereus and Pseudomonas aeruginosa, as well as cytotoxic effects against the human epithelial colorectal adenocarcinoma cell line (Caco-2). These results illustrated that stable emulsions required a mixture of SLs and soybean lecithin. Full article

This study investigated the inhibitory effect of nanoemulsions (NEs) derived from various essential oils (EOs) and seed oils (SOs) against pathogenic bacteria isolated from rainbow trout (Oncorhynchus mykiss). The EOs of eucalyptus, mandarin, and basil were extracted by hydrodistillation, while the SOs of avocado and pumpkin were extracted by supercritical fluids. GC–MS analysis determined the chemical composition, revealing that limonene (70.88%), eucalyptol (57.85%), and camphor (24.61%) were the main components of the EOs. The SOs were rich in palmitic acid (avocado) and linoleic acids (pumpkin) and contained phytosterols such as β-sitosterol and stigmasterol. Avocado seed oil had the highest total phenolic content and antioxidant activity. Eight stable NEs, prepared from individual and mixed oils, were tested against Salmonella enterica subsp. salamae, Escherichia coli, Klebsiella variicola, Bacillus oceanisediminis, and Bacillus thuringiensis. Most NEs were effective against E. coli and B. oceanisediminis, with an additive effect for SOs mixtures and a minimum inhibitory concentration of 0.53 μL/mL (E. coli), 0.53 μL/mL (B. oceanisediminis), and 2.13 μL/mL (B. thuringiensis). The bacteriostatic and bactericidal activity was 1.62 and 6 h with E. coli and NE Mix AP. These findings suggest that nanoemulsions containing SOs are promising candidates for controlling bacterial contamination in fishery products. Full article

Essential oils have attracted considerable attention as natural antimicrobial agents for food preservation due to their broad-spectrum activity against foodborne microorganisms. Although numerous studies report strong antimicrobial effects under in vitro conditions, their effectiveness in real food systems is often substantially reduced. This review critically examines the discrepancy between in vitro antimicrobial activity and actual performance in food matrices. Particular attention is given to the influence of food matrix interactions, physicochemical instability, volatility, sensory limitations, and microbial adaptation on the efficacy of essential oils. A conceptual framework is presented to systematically summarize the major factors limiting antimicrobial performance in practical food applications. In addition, current strategies aimed at improving applicability, including encapsulation technologies, nanoemulsions, synergistic combinations, and active packaging systems, are discussed. Available evidence indicates that simplified experimental models frequently overestimate the practical efficacy of essential oils. More realistic and system-oriented evaluation approaches are therefore necessary to improve the translation of laboratory findings into food applications. Overall, essential oils remain promising candidates for natural food preservation, although their successful industrial application will depend on overcoming important technological and practical limitations. Full article

Maintaining wellbore stability in deep and ultra-deep formations demands plugging agents capable of sealing nano- to micro-scale pores under high-temperature conditions. A core–shell nano-plugging agent (CSP) was synthesized via emulsion polymerization using KH-570-modified nano-SiO₂ as the rigid core and a poly(styrene-co-butyl acrylate-co-methyl methacrylate) terpolymer as the deformable shell. CSP particles had a mean diameter of 196.5 nm (polydispersity index, PDI = 0.183) and an onset decomposition temperature of 342 °C. Compatibility tests at 180 °C confirmed that 3 wt% CSP caused no adverse changes in the rheology or emulsion stability of the oil-based drilling fluid (OBM). At 180 °C, CSP reduced the high-temperature high-pressure (HTHP) filtrate loss by 64.4% and the permeability plugging apparatus (PPA) filtrate loss by 66.1%. Sand-disk tests elevated the breakthrough pressure from 1.5 to 9.2 MPa. Core displacement on sandstone cores achieved a plugging rate of 98.30%, and pressure transmission tests on natural shale cores extended the 50% equalization time by 7.8-fold. Comparative evaluation confirmed that the core–shell architecture consistently outperformed nano-SiO₂ alone, polymer alone, and their physical blend. Low-temperature N₂ adsorption provided direct evidence of pore sealing, with the treated-shale Brunauer–Emmett–Teller (BET) surface area and total pore volume reduced by about 62% (12.6 to 4.8 m²/g and 0.0325 to 0.0121 cm³/g, respectively). Scanning electron microscopy of the shale surface before and after treatment further provided direct visual evidence of pore sealing, showing the open, porous matrix being converted into a dense, compacted filter cake. Filter-cake thickness measurements are consistent with a proposed three-stage plugging mechanism—bridging, deformation filling, and thermal compaction—driven by the complementary roles of the rigid core and the deformable shell. These findings indicate that CSP merits further evaluation as a high-temperature plugging agent for wellbore stabilization in deep shale formations. Full article

This review examines the bioactive compounds of ginger (Zingiber officinale Roscoe), with a particular focus on metabolites and antimicrobial peptides exhibiting antimicrobial activity. The chemical composition, biological properties, and mechanisms of action of the major ginger-derived compounds are discussed, with emphasis on their antibacterial, antifungal, anti-inflammatory, and antibiofilm potential. Particular attention is given to their antimicrobial spectrum and to potential synergistic interactions with other natural bioactive compounds that may enhance their efficacy against pathogenic microorganisms. Despite their promising therapeutic properties, the application of ginger-derived molecules against skin-associated pathogens remains challenging due to their limited stability, poor bioavailability, and the protective effects of microbial biofilms, which reduce treatment effectiveness and contribute to persistent infections. Current strategies designed to overcome these limitations, including chemical modification, liposomes, nanoemulsions, and hydrogel-based delivery systems, are reviewed. In addition, this review highlights the potential of microalgae-based encapsulation systems as innovative and sustainable platforms for the delivery of ginger bioactives. Owing to their diverse biochemical composition and structural characteristics, microalgae represent a promising source of natural biomaterials for the development of diverse encapsulation strategies. These emerging systems may potentially improve the stability, controlled release, bioavailability, and antibiofilm efficacy of ginger-derived compounds, supporting the development of novel formulations for the management of biofilm-associated skin infections. Full article

Background: Oil-in-water nanoemulsions (NEs) represent versatile platforms for the delivery of hydrophobic compounds and find a wide range of applications in different fields such as food, cosmetics, agriculture, pharmaceutics, and oil and gas industries. Various methodologies can be applied for the preparation of NEs as low-energy and high-energy methods. Among them, high-energy ultrasonication (HEU) is a popular technique in research laboratories or small manufacturing facilities. However, a clear gap remains in understanding how, and to what extent, experimental parameters and the chemical and physical characteristics of the components affect the formation and properties of NEs through HEU. Methods: In this work, a comprehensive screening of factors (oil viscosity and density, surfactant type, processing parameters, and formulation composition) affecting NEs formation and quality was performed and an artificial neural network (ANN) was applied to determine the relative relevance of each parameter. Results: Oil viscosity revealed to be the primary factor affecting droplet size (Z_avg) and polydispersity index (PDI), with high-viscosity oils leading to poor emulsification into nanosized droplets. Higher processing temperatures improved NE formation by reducing viscosity during sonication. Ultrasound amplitude and pulse mode influenced NE characteristics, particularly under challenging conditions. Surfactant type and oil content had, instead, minor effects on the NEs’ features. ANN modelling accurately predicted NEs’ properties and identified critical viscosity limits for successful nanosized emulsification (Z_avg < 300 nm and PDI < 0.4). Conclusions: These findings provide a predictive basis for rational NE design under HEU, serving as a guide for researchers working in different fields. Full article

Oil-in-water nanoemulsions (NE) can increase the water solubility of plant-derived bioactive molecules as drug candidates. Machine learning-guided NE design can prevent the expensive, time-consuming trial-and-error process. NE composition data was aggregated into a dataset; a predictive machine learning model identified improved self-nanoemulsifying system formulations (olive oil and combinations of Tween 20, Tween 80, glycerol, and soy lecithin). Predictive power was assessed by estimating successful self-nanoemulsification through transmittance and Dynamic Light Scattering. NEs were loaded with an organic extract containing anacardic acid. Encapsulation efficiency was measured by UHPLC. Antiproliferative activity was evaluated on human hepatic cancer (Hep G2) and normal-like human embryonic kidney (HEK-293) cell lines. The model showed an accuracy of 81%. The best-performing formulation, consisting of 10% olive oil, 60% Tween 20, and 30% glycerol, exhibited an average particle size of 162.8 ± 26 nm, a polydispersity index of 0.234 ± 0.03, and high encapsulation efficiency. While HEK-293 cells remained unaffected, naked NE exhibited a selective growth inhibitory effect on the Hep G2 cell line. Loaded NE increased the cytotoxic effect on Hep G2 (IC50: 5.9 ± 1.27 µM). Machine learning-guided NE formulation was a successful carrier for the plant extract and the molecule of interest, providing a proof of concept for how artificial intelligence can shorten the development pipeline for NE drug delivery systems. Full article

The antimicrobial effect of Eucalyptus radiata essential oil nanoemulsion (EON) on Staphylococcus aureus and spoilage microorganisms was evaluated on fresh beef chunks during cold storage at days 0, 2, 4, 6, and 8. For this purpose, nanoemulsion was prepared using 2% eucalyptus oil combined with high methoxyl pectin, glycerol, and Tween 80, employing high shear force. Then the following were evaluated: (1) the essential oil’s chemical profile and in vitro antioxidant and antimicrobial capacities; (2) the nanoemulsion characteristics; and (3) the microbial counts of the beef treatments. The results showed that the essential oil’s primary components were o-cymene (45.4%), 2-bornene (26.29%), 1,8-cineole (11.31%), and α-pinene (9.25%). The EON had a particle size of 52.04 nm and a zeta potential of −9.16 mV. The in vitro studies revealed that both the essential oil and its nanoemulsion demonstrated significant antibacterial activity. Similarly, in in situ examinations, when the meat samples were spiked with S. aureus (0.1 × 10⁸ CFU/mL), the EON-treated meat samples had significantly (p ≤ 0.05) lower microbial counts than the untreated meat samples throughout the storage period; the difference between the treatments ranged between 1.62 and 2.44 log CFU/g. Additionally, the EON exhibited excellent antimicrobial efficacy against spoilage microorganisms on beef pieces during shelf life. On day 4, the maximum inhibitory activity was observed against total coliform, Pseudomonas spp., and yeast in reductions of 1.96, 2.09, and 2.18 log CFU/g in microbial counts, respectively. Moreover, application of meat samples with the EON delayed spoilage by 4 days. Therefore, the results of this study showed that coating beef chunks with the EON enhanced both product safety and shelf life. Full article

Celastrol, one of the top five traditional natural products with high potential for modern drug development, exerts potent broad-spectrum biological activities, yet its poor aqueous solubility, low bioavailability, potential toxicity, and limited selectivity severely compromise its drug-likeness. Advanced drug delivery strategies, mainly including multifunctional polymer/lipid/protein-based organic nanoparticles, metal/silica-based inorganic nanoparticles, vesicles represented by liposomes, and nanoemulsions, are expected to overcome these druggability hurdles of celastrol via oral, transdermal or intravenous administration. This review summarizes recent progress in a series of celastrol formulations, including novel dosage forms and delivery routes accompanied with consequential pharmacological effects and mechanisms of action, which have the potential to bring about better druggability conducive to future medical treatment. Full article

Background: Photodynamic therapy (PDT) is a promising minimally invasive approach for melanoma; however, many photosensitizers lose activity in aqueous media due to aggregation-induced quenching effects. Objectives: The aim of this study was to develop and characterize castor oil–based nanoemulsions containing chlorophyll (NFs-Chl) and to evaluate their in vitro photodynamic potential against melanoma cells (B16-F10), as well as their selectivity compared with human keratinocytes (HaCaT). Methods: NFs-Chl were prepared by spontaneous emulsification. Physicochemical characterization was carried out using dynamic light scattering (DLS), UV–Vis spectroscopy, FTIR, and Raman spectroscopy. In vitro assays included MTT for cell viability (IC₅₀ determination), real-time cell proliferation (RealTime-Glo™), and cell migration analysis (scratch assay). All photodynamic treatments were performed under irradiation at 660 nm. Results: NFs-Chl exhibited homogeneous nanometric sizes (≈24–31 nm) and a low polydispersity index (≈0.25–0.40), indicating a narrow size distribution. UV–Vis spectra confirmed the preservation of the characteristic absorption peaks of chlorophyll after encapsulation. In B16-F10 cells, NFs-Chl associated with PDT significantly reduced cell viability and metabolic activity over 48 h. Furthermore, NFs-Chl inhibited the migratory capacity of B16-F10 cancer cells. Cell migration assays revealed a clear inhibition of B16-F10 cell migration following treatment with NFs-Chl + PDT. Conclusions: Encapsulation of chlorophyll into castor oil nanoemulsions protected the photosensitizer, improved its cellular delivery, and enhanced its photodynamic cytotoxic effect against melanoma cells, while relatively preserving normal keratinocytes in vitro. Full article

Usnic acid (UA), a prominent lichen secondary metabolite, exhibits a unique dual therapeutic profile in dermatology, though its clinical translation is limited by systemic hepatotoxicity and poor solubility. This review comprehensively evaluates the topical efficacy, molecular mechanisms, and advanced formulation strategies of UA enantiomers and UA-rich extracts. A literature search across PubMed, Scopus, and Google Scholar identified 36 original publications focusing on anti-melanoma activity, photoprotection, and tissue regeneration. In vitro studies demonstrate that UA induces apoptosis in resistant melanoma cell lines (A375, HTB-140) via extrinsic/intrinsic pathways, with (−)-UA effectively overcoming doxorubicin resistance. Conversely, in non-cancerous models, low concentrations of UA accelerate wound and burn healing by upregulating vascular endothelial growth factor (VEGF), stimulating fibroblast proliferation, and optimizing extracellular matrix remodeling while preventing hypertrophic scarring. To mitigate skin sensitization and systemic risks, advanced drug delivery systems—including liposomes, nanoemulsions, chitosan nanogels, and electrospun scaffolds—have been developed, significantly enhancing skin permeability and localized dermal retention. Ultimately, the development of bio-functionalized smart dressings and targeted nano-formulations represents the most viable path toward unlocking the full clinical potential of UA in modern dermatological and oncological care. Full article

Mounting acaricide resistance in Tetranychus mexicanus (McGregor) (Acari: Tetranychidae), among the most damaging phytophagous mites in tropical and subtropical crops, has intensified the search for botanical alternatives. An oil-in-water nanoemulsion of Thymus vulgaris essential oil (TVEO-NE) was developed and evaluated for lethal and sublethal effects on adult females of T. mexicanus. TVEO, composed mainly of thymol (45%) and p-cymene (37%), was formulated by low-energy emulsification yielding stable dispersions (~200 nm; PDI < 0.25; zeta potential of −22.2 mV). At 30.0 mg a.i./mL, TVEO-NE caused 68.3% corrected mortality at 72 h and suppressed fecundity by ~44–52%; vehicle controls exerted only moderate effects, identifying the essential oil as the primary bioactive driver. Morphological examination revealed collapse of female idiosomata and disruption of excretory pellet architecture, corroborating the bioassay data. Molecular docking against a cathepsin L homology model revealed that thymol and p-cymene interact exclusively via hydrophobic contacts and display substantially lower ChemPLP fitness scores than the reference cysteine protease inhibitor E64, indicating weak predicted binding affinity and arguing against enzyme inhibition as the primary mechanism. Taken together, bioassay, morphological, and docking are consistent with supporting membrane partitioning as a plausible primary mode of action, positioning TVEO-based nanoemulsions as promising botanical tools for T. mexicanus management. Full article

Flavonoids are a structurally diverse class of plant-derived polyphenolic compounds widely recognized for their pleiotropic biological activities, including antioxidant, anti-inflammatory, and anticancer effects. In oncology, these compounds have demonstrated the ability to modulate key signaling pathways involved in cell proliferation, apoptosis, angiogenesis, and metastasis, highlighting their potential as multitarget therapeutic agents. However, their clinical translation remains significantly limited by unfavorable pharmacokinetic properties, such as poor aqueous solubility, extensive first-pass metabolism, rapid systemic clearance, and consequently low oral bioavailability. In this context, nanotechnology has emerged as a promising strategy to overcome these limitations. This review provides a comprehensive and critical analysis of current nanocarrier-based delivery systems for flavonoids, including polymeric nanoparticles, lipid-based nanocarriers (liposomes, solid lipid nanoparticles, and nanoemulsions), micelles, and cyclodextrin complexes, emphasizing their role in improving drug stability, enhancing cellular uptake, and enabling targeted delivery to tumor tissues through both passive mechanisms, such as the enhanced permeability and retention effect, and active targeting approaches. In addition, recent in vitro and in vivo studies demonstrating the superior antitumor efficacy of nanoencapsulated flavonoids compared to free compounds are discussed. Finally, the major translational challenges, safety considerations, and future perspectives for the clinical application of flavonoid-based nanomedicines in cancer therapy are highlighted. Full article

Excessive application of chemical preservatives has raised increasing concerns regarding food safety and human health, prompting the search for safer natural alternatives. Lavender essential oil (LEO), a plant-derived antimicrobial agent, has been considered a promising substitute for synthetic preservatives, but its high volatility and poor water solubility limit its practical application. In this study, LEO nanoemulsions were fabricated via high-pressure homogenization using sodium caseinate (SC) and tea polyphenols (TPs) as composite emulsifiers. The preparation process was optimized using a three-factor, three-level orthogonal design, and the physicochemical properties, storage stability, and antibacterial activity were systematically investigated. The optimal preparation conditions were determined as an SC/TP mass ratio of 2:1, homogenization pressure of 70 MPa, and 7 homogenization cycles. The optimized nanoemulsion exhibited a droplet size of 130–210 nm, zeta potential of −30.89 mV, and encapsulation efficiency of 98.61%, with typical shear-thinning behavior and excellent storage stability. The percentage of free LEO remained below 7.5% within 15 days, indicating high stability, and the release behavior followed a zero-order kinetic model. The prepared nanoemulsion showed significant antibacterial activity against Staphylococcus aureus and Escherichia coli, with a minimum inhibitory concentration (MIC) of 62.5 μg/mL for both strains. This study confirms that the SC/TP composite interface can effectively stabilize LEO nanoemulsions, providing a theoretical basis for the development of natural and efficient food preservatives. Full article