Search Results (1,149)

Magnesium alloys exhibit promising application prospects in medical orthopedic implants. However, their practical applications are limited by rapid corrosion, suboptimal osseointegration, and implant-related infections. Although conventional drug-eluting polymer coatings can provide various biological functions, the uncontrolled drug release often compromises long-term therapeutic efficacy. In this study, a self-healing Mg-poly(ε-caprolactone) (PCL)@OHF coating is designed and prepared on WE43 Mg by spin coating to achieve ultrasound-triggered release of osthole. OHF consists of osthole-loaded hollow mesoporous silica nanoparticles (HMSs) modified with Pluronic F127. Drug release studies show that the nanocapsules respond to ultrasound stimulation, with the cumulative release increasing from 39.94% to 75.93% after 7 days. Furthermore, the coating demonstrates intrinsic self-healing capacity upon thermal treatment at 50 °C. Electrochemical and immersion tests reveal that the composite coating provides good barrier protection for the WE43 Mg alloy, evidenced by a decrease in corrosion current density from 2.04 × 10⁻⁶ to 5.94 × 10⁻⁷ A/cm². In vitro biological assays confirm the antibacterial efficacy against Staphylococcus aureus and Escherichia coli, as well as the ability to promote osteogenic differentiation. The results reveal a surface modification strategy that combines self-healing, anticorrosion, and on-demand drug release, offering a promising approach for advanced orthopedic implants. Full article

Selenium nanoparticles (SeNPs) represent promising bioactive agents due to their reduced toxicity and multifunctional biological properties. In this study, SeNPs were synthesized via an eco-friendly phytosynthesis approach using Curcuma longa extract, yielding curcumin-functionalized selenium nanoparticles (cur–SeNPs). The composites (cur–SeNPs), either in native extract form or isolated, were incorporated into siloxane hybrid matrices prepared by the sol–gel method from tetraethyl orthosilicate: dimethyldimethoxysilane precursors, with polyvinylpyrrolidone (PVP) as a structural modifier. The host matrices were differentiated by the ratios between the precursors of the siloxane network, 3:1 for CS0–CS4, respectively, 1:1 for CS5, modified with PVP in the case of CS2 and CS3. These were loaded with cur–SeNPs–T in the cases of CS1, CS2, CS5 or with cur–SeNPs for CS3 and CS4. FTIR, XRD, SEM, and EDX analyses confirmed the formation of amorphous siloxane networks with well-dispersed SeNPs (up to ~12 wt%). PVP incorporation generated ordered mesoporous structures, increasing total pore volume sixfold and enlarging the average pore diameter to 9.26 nm. Studies about selenium ion release demonstrate that mesoporosity significantly enhances diffusion-controlled release. Antimicrobial assays against Staphylococcus aureus, Escherichia coli, and Candida albicans reveal a synergistic effect between curcuminoids and SeNPs, particularly in matrices with higher nanoparticle loading. The sol–gel technique for obtaining hybrid materials is very versatile regarding the supports on which the resulting materials or the compounds hosted in these host networks can be deposited. The dynamics of the development of hybrid materials is also reflected in the multitude of applications in various fields such as bio-medical, electronics, agriculture or food. Results obtained in this work highlight the potential of the developed systems for antimicrobial coatings on glass substrates and targeted delivery applications. Full article

Hybrid supramolecular–nanocomposite hydrogels based on polyethylene glycol (PEG), β-cyclodextrin–adamantane host–guest interactions, and silica nanoparticles represent an important class of hierarchical soft materials with tunable viscoelastic and transport properties. This review critically analyzes recent progress in cyclodextrin–silica hybrid PEG hydrogels, focusing on the mechanistic coupling between stiffness, stress relaxation, and molecular transport arising from the interplay between reversible supramolecular crosslinks and nanoparticle-induced confinement effects. Particular attention is given to how host–guest exchange kinetics regulate dynamic bond rearrangement and affinity-mediated retention of hydrophobic cargo, while silica nanoparticles enhance mechanical reinforcement and modify diffusion pathways through tortuosity and interfacial polymer–particle interactions. The analysis highlights how nanoparticle size, loading level, and surface functionalization influence relaxation spectra and network topology, as well as how environmental stimuli may affect supramolecular bond stability and overall material performance. Comparison with alternative inorganic fillers and mesoporous silica architectures further clarifies the specific advantages of silica in achieving balanced mechanical stability and controlled transport behavior. Overall, current evidence indicates that hybrid CD–silica networks enable partial decoupling of stiffness, relaxation dynamics, and diffusion, although complete independence remains constrained by fundamental polymer physics relationships. These insights support the development of predictive structure–property frameworks for advanced biomedical and controlled release applications. Full article

A one-pot green combustion route was developed for the synthesis of ashy single-crystalline NiO nanoparticles using date molasses as a biogenic fuel and complexing medium. The obtained DM–NiO showed phase-pure cubic NiO with an average crystallite size of about 18 nm, a mesoporous texture with a BET surface area of 68.9 m² g⁻¹, a pore volume of 0.59 cm³ g⁻¹, an average pore diameter of 17.6 nm, and a mean particle size of 43.6 ± 8.13 nm. Optical characterization revealed defect-mediated light absorption with an energy gap of 3.11 eV, supporting solar-light-driven activity. In the photocatalytic degradation of pyronin Y, the catalyst exhibited strong pH dependence, reaching its best H₂O₂-free performance at pH 11 with a pseudo-first-order rate constant of 0.0072 min⁻¹, nearly six times higher than that at pH 3. The introduction of H₂O₂ markedly intensified the process, and at 9 mM H₂O₂, the rate constant increased to 0.048 min⁻¹, representing more than a sixfold enhancement over photocatalysis alone, while complete disappearance of the main visible absorption band was achieved within 38 min under solar illumination. Radical trapping experiments identified photogenerated holes and hydroxyl radicals as the dominant oxidative species. The catalyst also retained high activity over four successive cycles, with degradation efficiencies decreasing only slightly from 91.8% to 85.7%. These results demonstrate that date-molasses-assisted combustion synthesis provides a sustainable route to defect-active mesoporous NiO with highly enhanced solar photo-Fenton-like performance for dye-contaminated wastewater treatment. Full article

Energy-efficient microwave technologies for the synthesis of zeolites and zeolite-like materials are considered. The use of microwave radiation in the process of material synthesis has a number of advantages, but also some disadvantages in comparison with the traditional hydrothermal synthesis method. The advantages and disadvantages of microwave synthesis of zeolites and zeolite-like materials are presented in the review. The use of microwave synthesis makes it possible to significantly reduce synthesis time, reduce energy costs, and obtain particles with a narrow distribution, usually in the nanoscale range (50–500 nm). The groups of zeolites considered include LTA, BEA, MOR, MFI, MEL, FAU, F, P, T, FER, ANA, MTT, ZSM–22, ZSM-48, SOD, SSZ-11, SSZ-13, SSZ-51, SSZ-54, and others. Among the zeolite-like materials synthesized using microwave radiation, mesoporous silicates MCM-41, SBA-15, alumophosphates, and metallaluminophosphates (AlPO-5, AlPO-11, AlPO-18, SAPO-5, SAPO-11, SAPO-34, SAPO-35) are considered. The proposed methods (microwave processing) significantly expand the range of methods for synthesizing new materials. These methods can reduce the synthesis temperature and affect the structure of the resulting materials. The proposed methods increase the likelihood of obtaining new nanomaterials and hybrid materials, as well as improving the properties of existing ones. Full article

Hydrogen peroxide (H₂O₂) plays a very vital role in industrial and biological processes, but its high concentration may cause health hazards. Therefore, accurate detection of H₂O₂ is crucial for chemical and biological sensing applications. In this work, a ratiometric fluorescent probe was developed using a core–shell structural silica nanoparticle for the detection of H₂O₂. Firstly, a silica core structure with red fluorescence emission was constructed by encapsulating a Schiff base compound (SD). Afterwards, a mesoporous silica shell was fabricated, and the AIE featured fluorophore with a H₂O₂ response character was covalently linked on the surface of the mesoporous shell layer. As recognition sites on the shell, blue-emitting TB molecules specifically identified H₂O₂ through their phenylboronic acid ester group. The blue fluorescence of core–shell structural nanoprobes would be quenched in the presence of H₂O₂, while red fluorescence remained unchanged, ensuring the high sensitivity and specificity of the ratio sensing. This design has demonstrated significant potential for the reliable monitoring of hydrogen peroxide in biological and environmental applications. Full article

Red Amaranth (RA) Azo dye is a persistent pollutant in wastewater and stands as a toxicological risk, which has led to the development of effective methods for its removal and photocatalytic degradation. Therefore, CeO₂ nanoparticles were synthesized by a controlled precipitation method, and Ultraviolet-Visible (UV–Vis) analysis and Tauc plots yielded a band gap of ~3.24 eV. The CeO₂ nanoparticles showed the fluorite cubic phase, and nearly spherical particles with an average size of ~10 nm. Nitrogen physisorption revealed a type IV isotherm with a Brunauer–Emmett–Teller (BET) surface area of 85.27 m²·g⁻¹ and a total pore volume of 0.27 cm³·g⁻¹, indicating a mesoporous structure and high surface accessibility. The chemical behavior showed Ce and O, consistent with phase purity. Photocatalytic performance was evaluated in 20 ppm aqueous solution of RA under 365 nm UV irradiation (LED 100 W), with a temperature of ~20 °C and a 15 min dark adsorption step. Concentration decay was followed at λ_max = 520 nm by Lambert–Beer. The degradation efficiency η and pseudo-first-order kinetic were obtained from ln(C₀/C_t) vs. time. In addition, chemical oxygen demand (COD) tests were performed on RA solution before and after photodegradation, showing a COD reduction of ~85% (from 19.8 to 3 mg O₂·L⁻¹), which corroborates mineralization beyond chromophore bleaching. Under [C₀ = 20 mg·L⁻¹] and [m_cat = 1.0 g·L⁻¹], CeO₂ achieved [RA = 90% at 180 min, k = 0.0125 min⁻¹]. These results demonstrate that CeO₂ is an effective photocatalyst for RA degradation under UV-A irradiation, integrating adsorption, kinetic behavior, and mineralization performance into a coherent structure–property relationship. Full article

The rational design of supported ruthenium catalysts for sustainable energy applications requires precise control over metal nanoparticle size, dispersion, and metal–support interactions. This study investigates the influence of mesoporous silica support topology—SBA-15 (2D hexagonal, cylindrical pores), SBA-12 (3D hexagonal structure), and SBA-3 (2D hexagonal)—on the structure and catalytic performance of 1 wt% ruthenium catalysts in CO₂ methanation and gas-phase toluene hydrogenation. Comprehensive characterization by nitrogen physisorption, low- and high-angle X-ray diffraction (XRD), H₂ temperature-programmed reduction (H₂-TPR), CO chemisorption, and transmission electron microscopy (TEM) revealed that support pore architecture dictates ruthenium particle size (1.2 nm for Ru/SBA-15, 2.8 nm for Ru/SBA-3, 4.3 nm for Ru/SBA-12) and dispersion (80%, 35%, 23%, respectively) through geometric confinement effects. Catalytic testing demonstrated contrasting structure–activity relationships: CO₂ methanation exhibited strong structure sensitivity with turnover frequency (TOF) increasing with particle size (Pearson’s r = 0.96), favoring Ru/SBA-3 and Ru/SBA-12 with near-optimal 3–4 nm particles, while toluene hydrogenation showed weaker structure sensitivity, with Ru/SBA-12 achieving the highest TOF owing to its larger particle size and higher crystallinity. These findings underscore the critical importance of tailoring mesoporous support topology to match reaction-specific structure sensitivity, providing fundamental insights for the design of bifunctional catalysts for hydrogenation reactions. Full article

Nanoparticle-catalysed microwave-aided multicomponent reactions (MCRs) have been demonstrated to be competent and environmentally benign tools for the quick synthesis of a wide spectrum of fused heterocyclic systems. The distinctive physicochemical properties of nanoparticles, including a substantial surface area, readily modifiable surface functionality, and heightened catalytic activities, when coupled with microwave irradiation, have enabled a marked improvement in reaction rates, product yields, and selectivity compared to conventional heating methods. This review highlights recent advancements in microwave-assisted MCRs facilitated by diverse nanomaterials, such as magnetic nanocatalysts, metal and metal oxide nanoparticles, mesoporous silica systems, and nanohybrids. It emphasises catalyst design, catalytic efficacy, scope, recyclability, and alignment with green chemistry principles in both solvent-free and aqueous environments, as well as the utilisation of recyclable catalysts. In summary, microwave-assisted multi-component reactions catalysed by nanoparticles are ecofriendly and versatile methods for the sustainable synthesis of such fused heterocycles containing bioactive pyridine, pyrazole, phenazine, pyrimidine, pyran, imidazole, and relevant pyridine derivatives, possessing potential in medicinal and material chemistry. Full article

Water pollution from the sugar industry is a significant environmental problem as it generates effluents containing organic compounds, solids, nutrients, and chemicals such as H₃PO₄, SO₂, and Ca (OH)₂. Mesoporous silica nanoparticles (MSNs) are a promising option for its treatment, due to their high surface area, and ease of functionalization using organically modified silanes (ORMOSIL) improving its adsorption of contaminants. The objective of this study is to remove anions (Cl⁻, SO₄²⁻, NO₂⁻, NO₃⁻) from the wastewater of a sugar mill in Campeche, Mexico and improve its physicochemical parameters (conductivity, turbidity, dissolved oxygen) using MSNs functionalized with 3-aminopropyltriethoxysilane (MSNs-APTES) or 3-(2-aminoethylamino)propyltrimethoxysilane (MSNs-3-2-A). The synthesized materials were characterized by FTIR and XPS analyses, which confirmed the incorporation of amino functional group and that MSNs-APTES exhibited a stronger N1s signal, indicating greater surface accessibility of amino groups. However, a partial surface masking under complex aqueous conditions was revealed. In contrast, MSNs-3-2-A showed lower apparent surface exposure of amino groups maintaining a more stable functional presence after exposure, likely due to its diamine structure promoting more confined interactions within the mesoporous framework. The results of removing anions and physicochemical parameters of wastewater exposed to MSNs indicate that treatments with MSNs-APTES and MSNs-3-2-A were able to significantly reduce the concentrations of SO₄²⁻, NO₂⁻ and NO₃⁻ anions, but not able to reduce the chloride ion. A decrease in turbidity and an increase in dissolved oxygen were also observed. Then, both materials proved to be functional and stable in contact with wastewater, demonstrating their potential for environmental remediation, particularly for the removal of anionic contaminants from sugar industry effluents. Full article

Mesoporous bioactive glass nanoparticles (MBGNs) are promising for bone tissue engineering; however, surgical site infection and oxidative stress often compromise regeneration. To address this, MBGNs co-doped with cerium (Ce), zinc (Zn), and strontium (Sr) were synthesized using a microemulsion-assisted sol-gel route (xCe-yZn-Sr-MBGNs; x = 0, 1, 2; y = 0, 0.5, 1). The resulting spherical nanoparticles (150–200 nm) exhibited a mesoporous structure with a specific surface area of (~340–425 m²/g), sustained ion release, and apatite formation in simulated body fluid. In vitro evaluations with MC3T3-E1 pre-osteoblasts demonstrated dose-dependent cytocompatibility, specifically in the co-doped formulations; however, higher Ce concentrations (2Ce-yZn-Sr-MBGNs) reduced viability following prolonged exposure. Crucially, the 1Ce-1Zn-Sr-MBGNs significantly enhanced osteogenic differentiation, as evidenced by a two-fold increase in osteogenic marker gene expression and a ~45% increase in calcium mineral deposition compared to undoped MBGNs within 14 days. Moreover, these particles accelerated cell migration, achieving ~70% scratch-wound closure within 24 h. Furthermore, 1Ce-1Zn-Sr-MBGNs displayed strong radical scavenging capacity and potent antibacterial activity against S. aureus and P. aeruginosa. These findings indicated that 1Ce-1Zn-Sr-MBGNs exhibited multiple therapeutic effects, including antibacterial, radical-scavenging, and osteogenic effects. By optimizing dopant ratios, these multifunctional nanomaterials emerge as promising candidates for next-generation bone grafts or implant coatings. Within the scope of this study, they demonstrated the capacity to simultaneously address three critical challenges in bone healing: controlling infection, mitigating oxidative stress, and promoting mineralized tissue formation. While these in vitro results provide a robust foundation, further in vivo validation is warranted to confirm their efficacy within complex physiological environments. Full article

The manipulation of the electrocatalyst nanoarchitecture, particularly transition metal compounds, regarding size, shape, facets, and composition, significantly enhances the electrocatalytic activity in energy transformations. This study introduces a novel methodology for the precipitation of mesoporous nanoparticles of nickel tungstate (meso-NiWO₄) using direct chemical deposition from a template of Brij^®78 surfactant liquid crystal. Physicochemical analyses revealed the formation of amorphous meso-NiWO₄ nanoparticles with dual sizes of 10 ± 3 and 120 ± 8 nm and a specific surface area of 34.2 m²/g, exceeding that of nickel tungstate deposited in the absence of surfactant (bare-NiWO₄, 4.0 m²/g). The meso-NiWO₄ nanoparticles exhibit improved electrocatalytic stability, reduced charge-transfer resistance (R_ct = 1.11 ohm), and a current mass activity of ~365 mA/cm² mg at 1.6 V vs. RHE during the electrolysis of urea in alkaline solution. Furthermore, by employing meso-NiWO₄ in a two-electrode urea electrolyzer, a remarkable 4.8-fold increase in the cathodic hydrogen concurrent production rate was achieved (373.40 µmol/h at a bias potential of 2.0 V), compared to that of the bare-NiWO₄ catalyst. The exceptional urea oxidation electroactivity and the enhanced hydrogen evolution rate arise from substantial specific surface area and mesoporous structure, facilitating effective charge transfer and mass transport through the meso-NiWO₄ catalyst. Using the surfactant liquid crystal template for electrocatalyst synthesis enables a one-pot deposition of diverse nanoarchitectures and compositions with high surface area at ambient conditions for an improved electrocatalytic and hydrogen green production process. Full article

Background/Objectives: Upon systemic delivery, macrophages take up a significant portion of nanoparticles and may become saturated. The saturation of macrophages may pose risks to overall immune function and signaling pathways. While some information is available on the survival and functionality of macrophages upon saturation with nanoparticles, there is limited understanding of the molecular-level changes that can occur and their corresponding influences on macrophage phenotypes, gene expression, and immune signaling pathways. Methods: In this study, RAW 264.7 macrophages were saturated with silica nanoparticles (SNPs) of different sizes (50 and 100 nm), porosities (nonporous, mesoporous), densities (solid, mesoporous, and hollow), and surface compositions (hydrophobicity) at their maximum non-toxic concentrations. The saturated macrophages were evaluated for changes in gene expression and immune signaling pathways by RNA sequencing, weighted gene co-expression network analysis (WGCNA), and Hallmark and KEGG pathway analyses. Results: Our results show that in the range studied, the particle size did not have a significant effect on the gene expression profile. Porous SNPs of comparable sizes resulted in increased and unique changes in the gene expression profile compared to nonporous SNPs. Major immune signaling pathways, including TNF-alpha signaling via NF-κB pathways, mTORC1 signaling, and p53 pathways, were modulated in SNP-saturated macrophages. This modulation depended on the physicochemical properties of the particles. The Th1/Th2 multiplex immunoassay revealed that the uptake of SNPs increases the amount of the TNF-alpha cytokine compared to the nontreated controls, whereas no changes in IL-6 and IL-12p70 pro-inflammatory cytokines were observed. Conclusions: Our results demonstrate that physicochemical properties of SNPs, such as porosity, size, surface functionality, and density, influence the modulation of gene expression and macrophage immune signaling pathways. These results, along with others, can provide guidance on the selection of silica nanoparticles for the safe and effective systemic delivery of bioactive agents. Full article

Background: Quercetin (Q) can reduce cellular oxidative stress, though it is susceptible to degradation in physiological conditions. Through adsorption and protection of Q, mesoporous silica nanoparticles (MSNs) could enhance its bioactivity. This work aimed to determine the effect of Q loading in MSN and in its aminated (A-MSN), carboxylated (C-MSN) or thiolated (T-MSN) derivatives on its Caco-2-cytoprotective effect against H₂O₂-induced oxidative stress. Methods: The mesoporous silica materials were characterized (FT-IR, ζ-potential, TGA), and their cytotoxicity was assessed; then, they were loaded with Q and incubated with Caco-2 cells prior to oxidative stress induction, and the cytoprotective effect was evaluated through measurement of cell viability. Results: None of the nanoparticles showed toxicity to Caco-2 cells. A-MSN showed the highest Q loading capacity (5.26% ± 0.06%), due to hydrogen-bonding interactions. C-MSN clearly enhanced the Q cellular uptake compared to the other nanoparticles. Oxidative stress decreased Caco-2 cell viability, which was prevented by 100 µM free Q after 18 h incubation. In contrast, higher cell viability than in non-stressed cells was observed with the same Q concentration loaded across all nanoparticle types. Conclusions: Despite the high instability of free quercetin under cell culture conditions, it exerted a time-dependent cytoprotective effect against H₂O₂-induced oxidative stress that was enhanced upon loading into nanoparticles. Prior release of the Q molecule in the medium is ineffective, and the presence of the loaded material is required. Full article

The solubilization of poorly water-soluble drugs remains a critical challenge in pharmaceutical research. The formulation of solid dispersions employing mesoporous silica nanoparticles (MSN) constitutes a key strategy for enhancing the hydrophilicity and oral bioavailability of Biopharmaceutics Classification System (BCS) Class II drugs. Although several commercial mesoporous silica excipients have been approved for pharmaceutical use, there remains room for improvement regarding drug loading capacity, stability, and controllability of drug release. Methods: for this purpose, dendritic mesoporous silica nanoparticles (DMSN) with a radial dendritic structure and pH-responsive degradation properties were designed and synthesized using celecoxib (CEL) as the model drug, featuring a pore size of 21.51 nm. CEL was loaded onto DMSN and seven commercial solid dispersion excipients using the solvent evaporation method. Results: owing to its high surface area, pore volume, and radial structure, DMSN achieved 39.72% drug loading in an amorphous state, markedly improving wettability, dissolution, and physical stability. Accelerated stability tests showed that DMSN inhibited recrystallization, outperforming traditional solid dispersions. Pharmacokinetic studies in rats demonstrated that the oral bioavailability of CEL-DMSN was 1.29-fold higher than that of commercial celecoxib capsules. Conclusions: in conclusion, these results confirmed the potential of DMSN in enhancing the stability, promoting oral absorption, and reducing gastrointestinal irritation of poorly soluble drugs. Full article