Search Results (909)

Conventional amine-based solvents such as monoethanolamine (MEA) and diethanolamine (DEA) are widely used for CO₂ removal from natural gas but this technology suffers from drawbacks including high regeneration energy, solvent degradation, and corrosion issues. To overcome these limitations, this study investigates the use of newly synthesized hydrophobic protic ionic liquids (HPILs) composed of ammonium cations coupled with the bis(trifluoromethane)sulfonylimide ([Tf₂N]⁻) anion for CO₂ absorption using the pressure-drop method. The results show that CO₂ solubility increases with pressure but decreases with temperature. Among the studied ionic liquids (ILs), [BEHA][Tf₂N] exhibits the highest CO₂ capacity at 298.15 K within the pressure range of 1–20 bar, which is consistent with its free volume (V_f) value. Furthermore, a comparison study indicates that all ILs demonstrate superior CO₂ selectivity over methane (CH₄) at 298.15 K. The recyclability study shows that [BEHA][Tf₂N] maintains its structural integrity over two CO₂ absorption cycles at 20 bar across all tested temperatures. Full article

Background: The use of preservative agents in eye drop solutions may worsen symptoms of ocular surface disease, which is a highly prevalent syndrome worldwide. Preservatives are often used in pharmacotherapy of glaucoma, another disease concerning tens of millions of people around the globe. These numbers are predicted by the World Health Organization and are predicted to increase with time due to constant aging of populations. Methods: PubMed and Scopus databases were searched for articles investigating the topic of ocular surface disease in relation with glaucoma pharmacotherapy, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The aim of this review is to summarize the effect of various solvents used in drug formulations and ways to quantify their impact on the ocular surface. Discussion and Conclusions: Topical ophthalmic preservative-free formulations are better tolerated and less burdensome for all patients. They should be considered especially for glaucoma patients, who are expected to take medications for years, up to decades or a lifetime in many cases. Due to the chronicity of dry eye disease and the lack of reliable ways for lacrimal and meibomian gland renewal, primary prophylaxis is of uttermost importance. Unfortunately, despite the development of many measuring devices, the standardization of diagnostic methods poses a challenge due to high variability of results which are influenced by a myriad of factors—local, internal, and external. Full article

Background and Objectives: This study investigated the antioxidant, lipid-lowering, and hepatoprotective effects of two fenugreek seed varieties, Trigonella foenum-graecum (TFG) and Trigonella corniculata (TC), and analyzed their bioactive potential using various solvents, doses, and biochemical parameters. Materials and Methods: Antioxidant analyses, including ferric-reducing antioxidant power (FRAP), total phenolic content (TPC), and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assays, were conducted, and interventional studies were performed on rats divided into groups receiving disease + standard basal diet (G₀), standard basal diet only (G₁), and disease + standard basal diet supplemented with TC or TFG at 400 mg/kg/day (G₂, G₃) and 800 mg/kg/day (G₄, G₅). Biochemical blood tests assessing lipid profiles and liver function parameters, coupled with histopathological examination of the liver and heart tissues, were also performed. Results: Antioxidant assessments indicated that TFG exhibited greater free radical scavenging ability, higher total phenolic content, and stronger ferric-reducing power than TC did. In the in vivo experiments, both TFG and TC significantly enhanced lipid profiles by reducing total cholesterol, low-density lipoprotein cholesterol (LDL-c), very-low-density lipoprotein cholesterol VLDL-c, and triglycerides while boosting high-density lipoprotein cholesterol (HDL-c) levels (p < 0.001). Liver function tests indicated significant decreases in bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels with dose and plant effects, particularly at 800 mg/kg (G₅). Histopathological examination revealed that TFG at a dose of 800 mg/kg led to an almost normal liver structure and intact myocardial fibers with minimal inflammation, whereas TC groups displayed slight vacuolation of hepatocytes and some inflammatory responses. Conclusions: In conclusion, TFG shows the superior functional food properties of TFG in managing oxidative stress and hyperlipidemia in comparison to TC. Future studies should aim to elucidate the molecular mechanisms, optimize dosing regimens, and evaluate long-term safety and efficacy to support clinical applications. Full article

The development of advanced delivery systems for bioactive factors is a critical focus in regenerative medicine and tissue engineering. In this study, we present a waterborne polyurethane (WPU)-based scaffold fabricated through a fully aqueous electrospinning process, providing a solvent-free and green method for delivering secretome derived from human mesenchymal stromal cells (MSCs). We optimized the electrospinning parameters to enable efficient secretome incorporation while preserving fiber morphology, sterility, and biocompatibility. The resulting membranes exhibited a uniform nanofibrous architecture, supported high cell viability, and demonstrated effective secretome loading and release, detected following release of vascular endothelial growth factor (VEGF)-A over 24 h. Overall, our findings highlight the potential of WPU nanofibrous scaffolds as sustainable and functional platforms for the delivery of MSC-derived bioactive factors in biomedical applications. Full article

Rice bran, a rice milling by-product, is a rich source of bioactives such as tocopherols and γ-oryzanol, with promising antioxidant properties. This study compared three extraction techniques—Soxhlet, maceration, and supercritical CO₂ (SC-CO₂)—to identify the method offering the best balance of rice bran oil (RBO) recovery, composition, and sustainability. Although all methods yielded similar oil quantities (~9.5–10.8%), SC-CO₂ extraction achieved superior preservation of bioactives, with the highest tocopherol (116.9 µg/g) and γ-oryzanol (13.2 mg/g) levels. Antioxidant capacity, assessed via FRAP, ABTS, and DPPH assays, was consistently higher in SC-CO₂-extracted oil. The fatty acid profile further confirmed the advantages of SC-CO₂ extraction, with the oil showing a high proportion of unsaturated fatty acids (86.3%) and low saturated content (13.6%). In contrast, Soxhlet- and maceration-extracted oils contained higher saturated fractions (56.5% and 60.1%, respectively) and lower unsaturated content, reflecting the impact of thermal and solvent exposure on the lipid composition. Environmental impacts were quantified through cradle-to-gate life cycle assessment (LCA), showing that SC-CO₂ extraction led to the lowest ecological burden due to its solvent-free process and lower energy demand. Normalizing impacts on both oil yield and bioactive content further highlighted its advantages. These findings place SC-CO₂ extraction as a green, efficient alternative for valorizing rice bran, yielding a high-quality, antioxidant-rich oil suitable for food and cosmetic applications. The integrated chemical and environmental evaluation underscores the potential for a sustainable bioeconomy, effectively turning agricultural residue into functional ingredients. Full article

Background/Objectives: Dihydroquercetin, known for its broad biological activities, is a key component in dietary supplements and functional foods. This study aims to identify its novel pure solid forms, advancing understanding of its physicochemical properties and polymorphism. Methods: Systematic screening, preparation, and characterization efforts identified five solvates: dihydroquercetin monohydrate (1:1, S1 and S2), sesquihydrate (1:1.5, S3), dihydrate (1:2, S4), and ACN solvate (1:1, S5), along with one solvent-free phase (S6). Results: The crystal structures of the five solvates were successfully elucidated for the first time. A comprehensive suite of techniques, including single-crystal and powder X-ray diffraction, DSC, TG, and FT-IR, were employed to characterize the solvates and polymorphs. Hirshfeld surface analysis, void map analysis, intermolecular energy calculations, and energy framework methods were utilized to investigate the characteristics of the solvates. The crystal transformation relationships among these forms were also explored. Conclusions: Results demonstrate that O···H interactions dominate the intermolecular forces, accounting for over 35% of the total interactions. Full article

Dry reforming of methane (DRM) is a promising method for turning two major greenhouse gases, CO₂ and CH₄, into syngas (H₂ + CO). This syngas has the right H₂/CO ratio for making valuable chemicals and liquid fuels. However, there are significant challenges that make it tough to implement commercially. One big issue is that the process requires a lot of energy because it is highly endothermic, needing temperatures over 700 °C. This high heat can quickly deactivate the catalyst due to carbon build-up (coking) and the thermal sintering of metal nanoparticles. Researchers increasingly recognize mechanochemistry—a non-thermal, solid-state technique employing mechanical force to drive chemical transformations—as a sustainable, solvent-free strategy to address these DRM challenges. This mini-review critically assesses the dual role of mechanochemistry in advancing DRM. First, we examine its established role in creating advanced catalysts at lower temperatures. Here, mechanochemical methods help produce well-dispersed nanoparticles, enhance strong interactions between metal and support, and develop bimetallic alloys that resist coke formation and show great stability. Second, we delve into the exciting possibility of using mechanochemistry to directly engage in the DRM reaction at near-ambient temperatures, which marks a major shift from traditional thermocatalysis. Lastly, we discuss the key challenges ahead, like scalability and understanding the mechanisms involved, while also outlining future directions for research to fully harness mechanochemistry for converting greenhouse gases sustainably. Full article

This study explores the antioxidant, antibacterial, and cytocompatibility properties of aqueous Pinus pinaster bark extract (PBE). PBE was prepared using two solvent systems—100% distilled water and 1% DMSO in aqueous solution—at a solid-to-liquid ratio of 1:20 (w/v), following ISO guidelines. Extract characterization included yield determination, FTIR analysis, quantification of total phenolic (TPC) and flavonoid (TFC) contents, and assessment of antioxidant activity using four complementary methods: free radical scavenging (DPPH and ABTS), metal ion reduction (FRAP), and a competitive reaction assay (ORAC). The phenolic compound profile was further examined by HPLC-DAD. The results indicated that the two extracts exhibited comparable values across all evaluated parameters when expressed per gram of PBE. The TPC and TFC were approximately 400 mg GAE (gallic acid equivalents)/g PBE and 92 mg CE (catechin equivalents)/g PBE, respectively. Antioxidant capacity values were about 880, 1030, 3210, and 585 mg TE (Trolox equivalents)/g PBE for the DPPH, ABTS, ORAC, and FRAP assays, respectively. Furthermore, in both extracts, the phenolic and flavonoid contents exhibited strong positive correlations with antioxidant activity across all four chemical assays. The 100% aqueous extract was additionally evaluated for antibacterial activity and cytocompatibility with eukaryotic cells. Compared to the control, the extract demonstrated IC₅₀ values of 0.304, 0.678, and 0.845 mg/mL PBE for the inhibition of Staphylococcus aureus, Escherichia coli, and fibroblast cells, respectively. Antioxidant and antibacterial activities showed a positive association within concentration ranges that remained non-cytotoxic to fibroblasts. Overall, these findings indicate that the aqueous PBE retains cytocompatibility across a wide concentration range while maintaining both antioxidant and antibacterial activities, underscoring its potential for biological applications involving direct contact with eukaryotic cells. Full article

Microalgae are considered a potential source of fatty acid esters that are suitable for biodiesel production. However, a principal bottleneck in lipids extraction is related to the selection of appropriate solvents in order to obtain an efficient process. In this work, a simple methodology based on Hansen Solubility Parameters (HSP) was developed, aiming to solvent screening towards selective extraction of lipid compounds: main parameters that were considered for an optimum solvent included the partitioning of free fatty acids and other non-desired solutes, e.g., pigments and phospholipids, as well as the minimum water dissolution. The method takes into account the affinity of a candidate solvent with desired and non-desired solutes along with their relative differences. A large number of solvents (>5000) were scanned by this method for their capacity to selectively extract fatty acid esters from microalgae biomass, and hexane proved to be among the optimum solvents. This prediction was supported by the Snyder’s polarity index as well as ab initio quantum mechanical Density Functional Theory (DFT) calculations of the Gibbs free energy of solvation and partition coefficients. Moreover, model validation carried out by liquid–liquid extraction of algal liquor with hexane and other solvents, and measurement of lipids allocation using paper chromatography and spectroscopy. Low lipids yield was observed, while the extract was enriched in fatty acid esters. A critical discussion is provided regarding the low yield ratios and potential implications due to overestimation of lipids content in microalgae. Full article

The Raman spectrum of adenine and the surface-enhanced Raman spectrum (SERS) upon adsorption of adenine on an Ag₈ cluster in aqueous solution were calculated using the DFT/PBE0/Def2-TZVP method with the IEF-PCM solvent model. TD-DFT calculations were performed to determine the excitation wavelengths of adenine and the Ag₈•A complex, thereby selecting excitation wavelengths compatible with available experimental Raman spectroscopy instruments. In addition, excitation wavelengths with the maximum oscillator strength were chosen to propose characteristic spectra for experimental studies. The calculated Raman activities were converted into Raman scattering intensities, and the enhancement factor EF_int was determined. The results show that an excitation wavelength of 325 nm gives the strongest and most distinct SERS signal, 532 nm provides stable signals suitable for commercial instruments, while 442 nm significantly reduces several characteristic vibrational bands. Moreover, the Ag₈ cluster exhibits excellent enhancement of the Raman signal for adenine. This study provides a basis for selecting excitation wavelengths and characteristic vibrational modes to identify adenine, supporting the development of label-free biosensors based on silver clusters. Full article

Background/Objectives: Conventional solidification methods for liquid self-nanoemulsifying drug delivery systems face significant limitations. This includes complex manufacturing processes, high costs, and environmental concerns. This study aimed to develop and optimize a thermoresponsive self-nanoemulsifying drug delivery system (T-SNEDDS) for dapagliflozin as a sustainable alternative solidification technique. Methods: Oil and surfactant were selected based on solubility and emulsification studies. The Box–Behnken approach was used to examine the impacts of three independent variables (pluronic F127, propylene glycol, and dapagliflozin concentrations) on liquefying temperature and time. Optimized T-SNEDDS was characterized in terms of particle size, zeta potential, and dissolution performance. Stability assessment included centrifugation testing and a six-month storage evaluation. The green pharmaceutical performance was comparatively evaluated against five conventional solidification methods using ten adapted parameters. Results: Imwitor 308 and Cremophor EL were selected as optimal excipients for SNEDDS formulation. In addition, Pluronic F127 and propylene glycol were used to induce solidification during storage. The optimized formulation (8.60% w/w Pluronic F127, 10% w/w propylene glycol, and 5% w/w dapagliflozin) exhibited a liquefying temperature of 33.5 °C with a liquefying time of 100.3 s and a particle size of 96.64 nm. T-SNEDDS significantly enhanced dissolution efficiency of dapagliflozin (95.7%) compared to raw drug (42.4%) and marketed formulation (91.3%). Green pharmaceutical evaluation revealed that T-SNEDDS achieved the highest score compared to conventional approaches. Conclusions: T-SNEDDS represents a superior sustainable approach for SNEDDS solidification that offers enhancement in drug dissolution while addressing manufacturing, environmental, and economic challenges through its solvent-free and single-step preparation process with excellent scalability potential. Full article

Cationic polyelectrolytes, characterized by positively charged functional groups, play an essential role in industries ranging from food solutions, water treatment, medical, cosmetic, textiles and agriculture due to their electrostatic interactions, biocompatibility, and functional versatility. This paper critically examines the transition from petroleum-based synthetic polymers such as poly(diallyldimethylammonium chloride) and cationic polyacrylamides to sustainable natural alternatives derived from agri-forestry resources like starch derivatives and cellulose. Through a cradle-to-gate life cycle assessment, we highlight the superior renewability, biodegradability, and lower carbon footprint of bio-based polycations, despite challenges in agricultural sourcing and processing. This study examines cationization processes by comparing the environmental limitations of traditional chemical methods, such as significant waste production and limited scalability, with those of second-generation reactive extrusion (REX), which enables solvent-free and rapid modification. REX also allows for adjustable degrees of substitution and ensures uniform charge distribution, thereby enhancing overall functional performance. Groundbreaking research and optimization achieved through the integration of artificial intelligence and machine learning for parameter regulation and targeted mechanical energy management underscore REX’s strengths in precision engineering. By methodically addressing current limitations and articulating future advancements, this work advances sustainable innovation that contributes to a circular economy in materials science. Full article

The cashew apple (Anacardium occidentale L.) is rich in antioxidant bioactive constituents that have anti-aging and wound healing properties. The objective of this study is to evaluate the biological activities of cashew apple extract (CAE) and to improve the issue involving the instability of ascorbic acid, the principal active compound, by encapsulating the extract in liposomes in order to enhance its stability and skin permeation for cosmetic applications. CAE was obtained from fresh cashew apple via ethanol maceration, solvent evaporation, and freeze-drying. Ascorbic acid content, total phenolic content (TPC), total flavonoid content (TFC), and total caffeoylquinic acid content (TCQAC) were determined. The ascorbic acid content and its tautomer in the extract were quantified using the LC-MS/MS method. Biological activities, including antioxidant, anti-tyrosinase, fibroblast collagen synthesis, cytoprotection against oxidative stress, wound healing, and cytotoxicity, were assessed. CAE was encapsulated in liposomes to enhance the stability of its inherent ascorbic acid and improve its skin in comparison to free-CAE. The CAE and liposomal-CAE were incorporated and formulated into a solution, and their physicochemical stability was assessed after storage. CAE appeared as a brown, viscous liquid with a characteristic sweet, fruity scent. Each gram of CAE contained 0.90 ± 0.05 mg of ascorbic acid, TPC, 81.40 ± 7.14 mg of gallic acid equivalents (GAE), TFC, 3.73 ± 0.30 mg of rutin equivalents (RE), and TCQAC, 4.48 ± 0.05 mg of chlorogenic acid equivalents (CGAE). CAE exhibited antioxidant properties (IC₅₀ = 282.19 ± 11.16 and 963.66 ± 3.95 µg/mL for DPPH and ABTS assay, respectively) and weak anti-tyrosinase activity (IC₅₀ = 4213.77 ± 138.97 µg/mL). It was non-cytotoxic to fibroblast and monocyte cells at a concentration of less than 1 mg/mL. In vitro wound healing assays demonstrated that CAE stimulated collagen production in a dose-dependent manner at CAE concentrations above 250 µg/mL. Additionally, CAE exhibited cytoprotective effects against H₂O₂-induced oxidative stress and did not induce inflammatory responses in immune cells. The liposomal formulation containing CAE achieved high encapsulation efficiency (79.75–84.55%) based on ascorbic acid content. In skin permeation studies, CAE-loaded liposomes demonstrated an enhancement ratio approximately two-fold greater than that of free-CAE. Stability testing over 3 months showed that the ascorbic acid content in CAE-loaded liposomes remained significantly higher than that in the free-CAE under both refrigerated and long-term conditions (30 °C/75% RH). CAE demonstrated potential anti-aging properties for improving aging skin. Liposomal incorporation markedly improved ascorbic acid stability and skin permeability. Full article

Lycopene is a carotenoid with strong antioxidant properties, but its therapeutic potential is limited by its poor aqueous solubility. Developing formulations that enhance its solubility and stability may improve its bioavailability and effectiveness. This study aimed to prepare amorphous lycopene–PVP K30 systems via ball milling, a solvent-free and mild technique, and to evaluate their physicochemical properties, solubility, and antioxidant activity. Formulations containing 5%, 10%, and 15% lycopene (w/w) were obtained and characterized using X-ray powder diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopy. Density Functional Theory calculations were performed to gain molecular-level insights into lycopene–polymer interactions and hydrogen-bond formation. Solubility was determined by high-performance liquid chromatography, and antioxidant activity was evaluated using the DPPH radical scavenging assay. The amorphous dispersions exhibited enhanced solubility compared to crystalline lycopene, with the 10% system showing the highest initial solubility and antioxidant capacity, while the 5% formulation demonstrated superior stability over 24 h. Ball milling proved to be an efficient method for producing amorphous lycopene–PVP K30 dispersions with improved dissolution and bioactive performance. The results indicate that lycopene loadings between 5 and 10% offer the most favorable balance between solubility, stability, and antioxidant activity, supporting their potential use in pharmaceutical formulations. Full article

The fabrication of highly loaded and uniformly dispersed metal oxide nanoparticles (NPs) is much desired but still remains a great challenge. Herein, the NiO NPs exclusively confined in mesoporous silica SBA-15 were obtained by using nickel nitrate hydrate as a precursor through a facile solvent-free preparation method, which comprised manual grinding of Ni(NO₃)₂·6H₂O with SBA-15 and subsequent air calcination. Characterization results from X-ray diffraction (XRD) and transmission electron microscope (TEM) revealed that aggregation-free NiO nanoparticles with sizes of 3–5 nm were obtained at loading as high as 20 wt.% (weight%). Further increasing the NiO loading to 30 wt.% led to partial agglomeration of discrete nanoparticles to rod-like particles, while no external particles were observed. By comparing the sample derived from nickel acetate with exclusively external NiO particles, it was established that the pore confinement provided NiO nanoparticles with high thermal stability. Lastly, the catalytic performance of the prepared sample was evaluated in the model reaction of ammonia decomposition to CO_x-free H₂, and the stable NH₃ conversion of 93.7% was achieved at the weight hourly space velocity (WHSV) value of 30,000 mL·g⁻¹·h⁻¹ and at high temperature of 650 °C for 60 h, demonstrating the great potential of the solvent-free method in preparing thermally stable and robust supported catalysts. Full article