Search Results (2,495)

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

Combining montmorillonite (MMT), a layered silicate clay, with carbon quantum dots (CQD) is a promising strategy to develop hybrid nanomaterials with enhanced and tunable properties. In this work, we explore the structure–property relationships in montmorillonite–carbon quantum dot (MCQD) hybrid nanomaterials synthesized through two distinct routes. In Route 1, pre-synthesized CQDs using citric acid and urea as precursors were physically mixed with MMT, giving rise to MCQD-R1 hybrid nanomaterials. In Route 2, MMT was added in situ in the CQD reaction medium before thermal treatment, with contact times from 1 to 16 h, generating MCQD-R2-1 and MCQD-R2-16, respectively. Structural and spectroscopy techniques were employed to investigate the resulting hybrids. PXRD analysis revealed that the synthesis conditions preserved the crystalline structures of both CQD and MMT clay. The FT-IR indicated that in the MCQD-R1, the interactions with CQD occur primarily via the interlayer water molecules in MMT, whereas in the MCQD-R2-16 samples, the establishment of new chemical bonds involving the carbonyl group of CQD takes place. UV-Vis spectroscopy shows improved colloidal stability of MCQD-R2 hybrids compared to pristine CQDs. Finally, hemolysis assays demonstrated hemolytic activity below 5%, indicating good biocompatibility of the synthesized hybrid nanomaterials. Full article

In the aspect of water purification, a photoactive hybrid material based on reduced graphite oxide (RGO) with covalently, coordinatively, and through van der Waals interactions bonded zirconium(IV) phthalocyanine (PcZr) is proposed. In the material, the phthalocyanine complex plays the role of photosensitizer, while RGO is considered a carrier, ensuring high surface area and supporting PcZr activation. The central metal atom of PcZr directly interacts with lateral active oxygen-containing surface groups of graphite oxide, mainly –OH and –COOH. Thus, the proposed method of synthesis under solvothermal conditions allowed obtaining a relatively high concentration of the dye (0.2 wt.%) in the system based on a partially reduced and exfoliated graphite oxide. Optical studies confirmed the presence of PcZr through absorption and luminescence spectra. Additionally, effective generation of reactive oxygen species was demonstrated by testing the transformation of a dye indicator (diphenylisobenzofuran). Photocatalytic activity of the system was confirmed by photooxidizing selected organic dyes (methylene blue, Rhodamine B, Brilliant Green, and Eriochrome Black T) in a water medium, tested in slightly acidic conditions under red light. The greatest overall decrease in absorption during the photodegradation test was observed for Brilliant Green, reaching 88% after 3 h of irradiation. Full article

A novel 4H-benzo[h]chromene derivative was efficiently synthesized and structurally characterized as a β-enaminonitrile. Single-crystal X-ray diffraction confirmed its molecular structure, revealing a stable crystal lattice stabilized by intermolecular N–H···N hydrogen bonds and π–π stacking. The compound was evaluated for its inhibitory activity against both wild-type EGFR (EGFR^WT) and the resistant T790M mutant (EGFR^T790M). It exhibited moderate activity against EGFR^WT (IC₅₀ = 3.27 ± 0.72 μM) but demonstrated significantly enhanced potency against EGFR^T790M (IC₅₀ = 1.92 ± 0.05 μM), showing a low resistance factor compared to the reference drugs Erlotinib and Gefitinib. Comparative molecular docking studies against both wild-type and T790M mutant structures suggested that the compound maintains a stable binding mode involving key interactions with the hinge region residue Met769, rationalizing its ability to circumvent the T790M resistance mechanism. These findings identify the 4H-benzo[h]chromene scaffold as a promising lead for developing novel inhibitors to overcome EGFR^T790M-mediated resistance. Full article

This study investigates the effect of pyrite content on the flocculation and sedimentation of clay-based tailings composed of kaolin, quartz, and pyrite in seawater at pH 8. A high-molecular-weight anionic hydrolyzed polyacrylamide (SNF 704) was used in batch settling tests, supported by floc characterization with FBRM, zeta potential measurements, and molecular dynamics (MD) simulations. Results showed that increasing pyrite content reduced the maximum floc size and increased the fraction of unflocculated fines, particularly at 10 g/t dosage. Although the fractal dimension remained nearly constant (1.92–1.97 at 10 g/t and 2.05–2.08 at 30 g/t), floc density increased linearly with pyrite proportion due to its higher specific gravity. Zeta potential analysis confirmed strong polymer–pyrite interactions, with charge inversion from +5.3 to −4.5 mV, while MD simulations indicated that adsorption occurs mainly through aliphatic chain segments, in contrast to hydrogen bonding observed for quartz and kaolinite. These findings demonstrate that pyrite affects flocculation dynamics both by its density and by specific polymer–surface interactions, directly influencing floc size, density, and sedimentation performance in seawater thickening systems. Full article

Hydrogels are three-dimensional polymeric networks capable of retaining large amounts of water. Polyvinyl alcohol (PVA)-based hydrogels exhibit autonomous self-healing through reversible physical interactions within the hydrogel matrix, including hydrogen bonding, crystallite formation, and dynamic crosslinking. However, their long self-healing times and low strength limit practical application. Herein, we propose an effective strategy to simultaneously achieve excellent self-repairing and high mechanical strength. The tensile strength of uncut PVA hydrogel was 1.21 MPa; after cutting and rejoining for 12 h at room temperature (RT), it recovered 94% of the original uncut strength. To accelerate self-healing, hydrogels were treated at 40, 50, and 60 °C for 20, 40, and 60 min. Under optimal conditions (60 °C for 60 min), 96% recovery was achieved. Mechanical properties were further improved by silica (Si) nanoparticles of various sizes (~12, ~85, and ~200 nm). Si-loaded hydrogels, particularly ~12 nm, demonstrated increased mechanical properties, reaching a tensile strength of 1.45 MPa and a self-healing recovery of 95% of the uncut hydrogel strength. Ultra-small (~12 nm) Si nanoparticles enhanced the overall mechanical properties by acting as an efficient nucleating agent and did not hinder the existing self-healing mechanism. The developed strategy will pave the way for novel techniques in hydrogel research and will advance applications such as soft robotics and wound dressing. Full article

Human immunodeficiency virus (HIV-1) and SARS-CoV-2 continue to co-burden global health, motivating discovery of broad-spectrum small molecules. Conessine, a steroidal alkaloid, has reported membrane-active and antimicrobial properties but remains underexplored as a dual antiviral chemotype. To interrogate conessine’s multi-target antiviral potential against key enzymatic and entry determinants of HIV-1 and SARS-CoV-2 and to benchmark performance versus approved comparators. Eight targets were modeled: HIV-1 reverse transcriptase (RT, 3V81), protease (PR, 1HVR), integrase (IN, 3LPT), gp120–gp41 trimer (4NCO); and SARS-CoV-2 main protease (M^pro, 6LU7), papain-like protease (PL^pro, 6W9C), RNA-dependent RNA polymerase (RdRp, 7BV2), spike RBD (6M0J). Ligands (conessine; positive controls: dolutegravir for HIV-1, nirmatrelvir for SARS-CoV-2) were prepared with standard protonation, minimized, and docked using AutoDock Vina v 1.2.0exhaustiveness 4; 20 poses). Binding modes were profiled in 2D/3D. Protocol robustness was verified by re-docking co-crystallized ligands (RMSD ≤ 2.0 Å). Atomistic MD (explicit TIP3P, OPLS4, 300 K/1 atm, NPT; 50–100 ns) assessed pose stability (RMSD/RMSF), pocket compaction (Rg, volume), and interaction persistence; MM/GBSA provided qualitative energy decomposition. ADMET was predicted in silico. Conessine showed coherent, hydrophobically anchored binding across both viral panels. Best docking scores (kcal·mol⁻¹) were: HIV-1—PR −6.910, RT −6.672, IN −5.733; SARS-CoV-2—spike RBD −7.025, M^pro −5.745, RdRp −5.737, PL^pro −5.024. Interaction maps were dominated by alkyl/π-alkyl packing to catalytic corridors (e.g., PR Ile50/Val82, RT Tyr181/Val106; M^pro His41/Met49; RBD L455/F486/Y489) with occasional carbon-/water-mediated H-bonds guiding orientation. MD sustained low ligand RMSD (typically ≤1.6–2.2 Å) and damped RMSF at catalytic loops, indicating pocket rigidification; MM/GBSA trends (≈ −30 to −40 kcal·mol⁻¹, dispersion-driven) supported persistent nonpolar stabilization. Benchmarks behaved as expected: dolutegravir bound strongly to IN (−6.070) and PR (−7.319) with stable MD; nirmatrelvir was specific for M^pro and displayed weaker, discontinuous engagement at PL^pro/RdRp/RBD under identical settings. ADMET suggested conessine has excellent permeability/BBB access (high logP), but liabilities include poor aqueous solubility, predicted hERG risk, and CYP2D6 substrate dependence.Conessine operates as a hydrophobic, multi-target wedge with the most favorable computed engagement at HIV-1 PR/RT and the SARS-CoV-2 spike RBD, while maintaining stable poses at M^pro and RdRp. The scaffold merits medicinal-chemistry optimization to improve solubility and de-risk cardiotoxicity/CYP interactions, followed by biochemical and cell-based validation against prioritized targets. Full article

As a chitosan (CTS)-based drug carrier (DC) for doxorubicin (DOX) delivery, poly(2-hydroxyethyl methacrylate-co-2-hydroxy-4-N-methacrylamidobenzoic acid) [poly(HEMA-co-2-HMBA)] (PHCH) was successfully grafted onto chitosan to fabricate DOX-loaded microparticles, and their in vitro release behavior was systematicaly investigated. Morphological characteristics were analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), while DOX loading was validated through Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), comparing pure and drug-loaded microparticles. The maximum loading capacity (~91%) was attributed to the presence of abundant carboxylic acid groups, which imparted pH responsiveness during in vitro DOX release. Furthermore, density functional theory (DFT) calculations revealed that hydrogen bonding interactions between DOX and the functional groups of the microparticles strongly influenced encapsulation efficiency (EE%), drug loading (DL%), and release behavior. The fabricated microparticles exhibited pH-dependent DOX release, with accelerated and more complete release at tumor microenvironment pH 5.5 compared to physiological pH 7.4. These results demonstrate that PHCH grafted CTS microparticles are promising candidates for controlled and site-specific anticancer drug delivery. Full article

The development of highly selective, sensitive and recyclable chemosensors for CN⁻ is critical due to the widespread use of cyanide derivatives in industrial processes and its extreme toxicity to environmental and biological systems. Herein, we report the synthesis and characterization of a water-soluble arene ruthenium metalla-assembly specifically designed to operate in aqueous solutions and under environmentally relevant conditions. The arene ruthenium assembly incorporates functionalized building blocks that enable a selective multi-site recognition of cyanide according to pH by either nucleophilic addition or hydrogen bond interactions. The system exhibits a distinct colorimetric response upon cyanide binding, resulting in a rapid “turn-on” color change. An excellent selectivity and reversibility for cyanide recognition is observed over multiple cycles, with a detection limit in the low micromolar range, thus laying the ground for the future development of sensing technology with supramolecular metal-based assemblies. Full article

A growing scientific interest in bioactive compounds from sea cucumbers is contributing to a broader recognition even in regions where their consumption is not common. This study evaluated the biological potential of a Holothuria forskali extract obtained through different extraction methods, including water extraction, ethanol–water extraction, and enzymatic hydrolysis. The hydrolysate (H), rich in low-molecular-weight peptides, yielded the highest antioxidant (30.6 ± 0.6 mg VitC Eq/g sample for ABTS and 10.7 ± 0.1 mg GAEs/g sample for Folin-reactive substances) and ACE-inhibitory (82.6%) activities. Based on these results, the hydrolysate was selected for encapsulation in two nanostructured delivery systems for comparative purposes: chitosan nanoparticles (NPs) and rapeseed lecithin liposomes (LPs). Both nanostructures were characterized in terms of size, ζ-potential, and polydispersity and subjected to simulated in vitro gastrointestinal digestion (GIDv) to assess their stability and mucoadhesive properties. After digestion, antioxidant activity increased in both systems, particularly in liposomes. Although encapsulation initially reduced ACE-inhibitory activity, gastrointestinal digestion restored or enhanced it, especially in liposomal formulations (≈37% inhibition). The mucoadhesive potential of the nanostructures after DGIv, focusing on their interactions with mucin, was assessed. Liposomal digests significantly increased viscosity in the presence of mucin, while chitosan nanoparticles decreased it, suggesting the formation of soluble complexes with reduced hydrodynamic volume. Electrostatic and hydrogen bonding interactions between chitosan and mucin were particularly evident in the NPH formulation. The rheological synergism parameter (Δη) revealed more negative values for NPs and NPHs, indicating stronger mucoadhesive interactions compared to controls and suggesting their suitability for mucosal delivery. These findings support the use of H. forskali hydrolysates as a source of functional bioactive compounds and highlight the potential of chitosan-based nanocarriers for enhancing their stability, bioaccessibility, and mucoadhesive properties in functional food or nutraceutical applications. Full article

Rubberized concrete is a novel green building material that enhances many features when rubber particles are incorporated into cement mortar, simultaneously yielding economic benefits through the recycling of waste tires. This study applies styrene–butadiene latex (SBL) for toughening treatment. The investigation delves into the mechanism by which SBL improves the interface between rubber and cement, encompassing macroscopic mechanical properties, microscopic structural characteristics, and nano-scale interfacial interactions. Macroscopic mechanical tests reveal a significant increase in flexural strength, shear strength, and compressive strength of the composite concrete upon the introduction of SBL and rubber. Specifically, the compressive strength improved by 8.8%, shear strength by 13.7%, and flexural strength by 18.9% at 28 days. Through electron microscopy observation of corresponding polymer cement concrete sections, observations reveal that SBL reinforces both interfaces and elucidates its bonding impact at the micro-level interface. Molecular dynamics (MD) modeling of SBL/rubber/CSH is employed at the nanoscale to compute and examine the local structure, dynamic behavior, and binding energy of the interface. The findings indicate that SBL mitigates interface impacts, enhances interface hydrogen bonds, van der Waals interactions, $\mathrm{C}\mathrm{a}-\mathrm{H}$ coordination bonds, and stability, consequently improving interfacial adhesion and fortifying the feeble interface bonding between organic polymers (rubber) and inorganic silicates (CSH). Full article

Constructing a zinc delivery system is crucial for scientific zinc supplementation. In this study, gelatin-based zinc-loaded hydrogels were constructed with the assistance of sodium alginate and a ZnSO₄ solution soaking method. The zinc loading capacity, texture properties, rheological properties, microstructure, and pH sensitivity of hydrogels under different ratios of gelatin to sodium alginate were investigated. Results showed that the loading of zinc by hydrogel was successfully achieved through a ZnSO₄ solution soaking method, and increasing the ZnSO₄ concentration was conducive to zinc loading and hydrogel structure strengthening. Adding sodium alginate further enhanced the zinc loading capacity of hydrogel. When the concentration of ZnSO₄ was 25 wt%, the zinc loading of hydrogel containing only gelatin and hydrogel with a 7:3 ratio of gelatin to sodium alginate was 29 mg/g and 52 mg/g, respectively. In addition, sodium alginate also endowed the hydrogel with a certain pH sensitivity. When the ratio of gelatin to sodium alginate was 7:3, the hydrogel showed obvious pH response behavior. Spectroscopy results revealed that zinc sulfate strengthened the hydrogel structure by inducing hydrophobic interactions and the formation of hydrogen bonds, while Zn²⁺ was bound to oxygen atoms through coordination bonds in hydrogel. These results could provide new ideas for the construction of zinc-loaded hydrogels. Full article

Recently, 3-hydroxy-4-pyridinones have been extensively studied as chelating bidentate agents of metal ions for various biomedical applications. This study reports the structural characterization and density functional theory (DFT) analysis of centrosymmetric calcium complex based on 4-(3-hydroxy-2-methyl-4-oxopyridin-1(4H)-yl) acetic acid (1). The structure of complex 1 was determined by X-ray crystallography. The 3-hydroxy-4-pyridinone ligand in the studied complex is bound to the calcium ion in the desired monodentate, non-bridging manner. The calcium ion has a coordination number of six and adopts a distorted octahedral geometry. Analyzed geometric characteristics corresponding to hydrogen bonds in the crystal. The theoretical study of intra- and intermolecular interactions utilized DFT with the PBE0-D3/def2-TZVP (Gaussian Inc., Wallingford, CT, USA) level of theory. The charge redistribution in the ligand was studied in comparison with the free acid molecule. Full article

Background: Solid dispersions (SDs) of etodolac (ETD), a poorly water-soluble drug model, were developed to enhance its solubility and dissolution rate by employing various preparation methods and hydrophilic or amphiphilic polymers. Methods: Polyvinylpyrrolidone-poly(vinyl acetate) copolymers (PVP/VA), hydroxypropyl methylcellulose (HPMC) and poloxamer were used as carriers, while cryo-milling and lyophilization were utilized as routine methods to SDs preparation. Obtained SDs were characterized by drug content, solubility, dissolution rate and moisture content. The physical structure of SDs was estimated via scanning electron microscopy (SEM), whereas differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were employed to assess the potential drug-carrier interactions. Results: SD formulations demonstrated enhanced solubility of ETD in aqueous media, including water and buffers (pH 5.5 and 7.4). DSC analysis confirmed that PVP/VA and poloxamer ensured better ETD dissolution and protection against recrystallization. Furthermore, FTIR indicated the formation of hydrogen bonds between ETD and polymer, particularly in lyophilized dispersions. Conclusions: The optimized SD formulation for ETD contained PVP/VA and/or poloxamer as carriers and was obtained via lyophilization. This SD formulation exhibited the most favorable properties, enhanced the solubility and dissolution of ETD in aqueous media and effectively reduced its crystallinity. Full article

The development of advanced drug delivery systems is essential for improving therapeutic efficacy, particularly in the treatment of neurodegenerative disorders such as Alzheimer’s disease. This study investigates zinc-modified mordenite zeolite (MR-ZN) as a novel platform for the controlled delivery of donepezil (DPZ), a cholinesterase inhibitor. Natural mordenite was modified with zinc, enhancing its surface area from 62.1 to 85.4 m²/g and improving its adsorption properties. Donepezil was successfully loaded at two doses (10 mg and 23 mg), achieving high loading efficiencies of 95% and 94%, respectively. Adsorption kinetics followed a pseudo-second-order model (R² > 0.99), indicating that chemisorption predominates through coordination between DPZ functional groups and Zn²⁺ sites, while complementary physisorption via hydrogen bonding and van der Waals interactions also contributes to molecular stabilization within the zeolite framework. In vitro release studies under simulated gastrointestinal conditions demonstrated sustained and pH-responsive release profile with 80% and 82% of donepezil released after 24 h for 10 mg and 23 mg formulations, respectively. Density Functional Theory (DFT) calculations revealed favorable adsorption energy (−26.4 kJ/mol), while Bader and Electron Localization Function (ELF) analyses confirmed hydrogen bonding and electrostatic interactions without compromising the zeolite framework. These findings validate MR-ZN as structurally stable, efficient, cost-effective and biocompatible matrix for oral drug delivery. The combination of experimental data and theoretical modeling supports its potential to improve bioavailability and therapeutic performance in neurodegenerative treatment. Full article