Search Results (153)

Background/Objectives: Plant-derived bioactive compounds like syringic acid, a phenolic acid from the shikimic acid pathway, have shown potential against chronic diseases, including diabetes, cardiovascular disorders, cancer, and cerebral ischemia. However, its poor water solubility and rapid systemic elimination result in low oral bioavailability, limiting therapeutic potential. This study aimed to enhance its oral bioavailability using MIL-100(Fe), a metal–organic framework (MOF) known for high surface area and drug-loading capacity. Methods: MIL-100(Fe) was synthesized using an optimized method and loaded with syringic acid through impregnation at 12, 24, 36, and 48 h. Characterization included PXRD, FTIR, BET, SEM, and DLS. Acute oral toxicity was evaluated following OECD 423 guidelines, and bioavailability was assessed in Sprague Dawley rats. Results: The 1:2 MIL-100(Fe) to syringic acid ratio achieved the highest drug loading at 64.42 ± 0.03% (12 h). PXRD and FTIR confirmed successful loading (notably at 1239.2 cm⁻¹), and TGA indicated thermal stability at ~350 °C. SEM revealed octahedral particles with an average size of 270.67 ± 2.60 nm. BET showed reduced surface area post-loading. In vitro drug release exhibited media-dependent profiles. Toxicity tests indicated no adverse effects at 2000 mg/kg. Oral administration of SYA@MIL-100(Fe) resulted in a 10.997-fold increase in relative bioavailability versus oral syringic acid and a 12.82-fold increase compared to intraperitoneal administration. Conclusions: MIL-100(Fe) is a safe and effective oral carrier for syringic acid, significantly enhancing its bioavailability. This platform shows strong potential for delivering phenolic compounds in pharmaceutical applications. Full article

The development of efficient antibiotic-releasing materials derived from sustainable and recyclable compounds represents a key area within biomedical materials science, particularly in the treatment of antibacterial infections. Herein, a Fe³⁺/terephthalate-based metal–organic framework (MIL-53) and a novel advanced material made of MIL-53 with biogenic hydroxyapatite (1) were prepared by solvothermal reactions, and these were studied in detail as a Penicillin-G-releasing material. After loading Penicillin G on 1 and MIL-53, the antibiotic percentage release was studied, and the antimicrobial effectiveness of each material was evaluated against two bacterial ATCC strains (E. coli and S. aureus) and various Penicillin-G-resistant uropathogenic strains such as E. coli isolates (HHM 25, ERV 6, and FGI 4). Functional, structural, and morphological characteristics of these materials were thoroughly studied by analytical tools (FTIR, XRD, BET, SEM-EDS, and XPS). The Penicillin G load did not exceed 50% in both materials. The Penicillin G adsorption mechanism involves several types of interactions with the materials. The release of the antibiotic was more efficient from MIL-53, where the load did not exceed 20%. The release was analyzed using mathematical models. They indicated that when Penicillin G is released from MIL-53, the process follows diffusion through a uniform matrix; however, 1 is more porous, which helps with the release by diffusion of Penicillin G, and 1 exhibits more than a 90% inhibition of the growth of bacteria and strains like MIL-53. This suggests a valuable approach to antibiotic activity against resistant pathogens. The use of composite materials derived from the Fe-MOF with a sustainable matrix of hydroxyapatite as antibiotic-releasing materials has been unexplored until now. Full article

Aerogel sponges of bio-based polymers loaded with metal–organic frameworks (MOFs) are highly promising for environmental applications, but a central challenge is to improve their stability and efficiency for removal processes. Here, the effective incorporation of the MOFs MIL-100(Fe) and ZIF-8 in composite aerogels of chitosan–pectin–lactic acid is reported. The presence of pectin was critical to loading the MOFs efficiently and homogeneously, while the incorporation of lactic acid induced a large increase in the Young’s modulus and provided structural preservation in aqueous solutions. The presence of MOFs enhanced the removal of two dyes, methyl orange (MO) and methylene blue (MB), under batch and flow conditions, with removal efficiencies of methyl orange of about 85% and 90% when loaded with ZIF-8 and MIL-100(Fe), respectively. Bentonite, celite 545, and two ionenes were loaded for comparison. Factors beyond charge-to-charge electrostatic interactions influenced the removal, since no correlations were obtained between the electrical charges of dyes, fillers, and polymers. The kinetic data were analyzed by adapting the Langmuir kinetic model, incorporating absorption and desorption processes, which allowed the recovery of the respective rate constants. Full article

Arsenic (As) and cadmium (Cd) in rice grains are major global food safety concerns. Iron (Fe) can help reduce both, but current Fe treatments suffer from poor stability, low leaf absorption, and fast soil immobilization, with unclear underlying mechanisms. To address these issues, an Fe-based metal–organic framework (MIL-88) was modified with sodium alginate (SA) to form MIL-88@SA. Its stability as a foliar inhibitor and its leaf absorption were tested, and its effects on As and Cd accumulation in rice were compared with those of soluble Fe (FeCl₃) and chelating Fe (HA + FeCl₃) in a field study on As–Cd co-contaminated rice paddies. Compared with the control, MIL-88@SA outperformed or matched the other Fe treatments. A single foliar spray during the tillering stage increased the rice yield by 19% and reduced the inorganic As and Cd content in the grains by 22.8% and 67.8%, respectively, while the other Fe treatments required two sprays. Its superior performance was attributed to better leaf affinity and thermal stability. Laser ablation inductively coupled plasma–mass spectrometry (LA–ICP–MS) and confocal laser scanning microscopy (CLSM) analyses revealed that Fe improved photosynthesis and alleviated As–Cd stress in leaves, MIL-88@SA promoted As and Cd redistribution, and Fe–Cd co-accumulation in leaf veins enhanced Cd retention in leaves. Full article

In this study, a pH-responsive nanophotosensitizer (MT@Ce6) was rationally developed by strategic integration of MIL-101 (Fe)-NH₂ metal–organic framework with tannic acid (TA) and chlorin e6. This nanocomposite exhibits pH-responsive degradation in acidic microenvironments, facilitating Fe³⁺ release and subsequent reduction to Fe²⁺ that catalyzes Fenton reaction-mediated hydroxyl radical (•OH) generation. This cascade reaction shifts reactive oxygen species (ROS) predominance from transient singlet oxygen (¹O₂) to the long-range penetrative •OH, achieving robust biofilm disruption and over 90% eradication of methicillin-resistant Staphylococcus aureus (MRSA) under 660 nm irradiation. In vivo evaluations revealed accelerated wound healing with 95% wound closure within 7 days, while species-selective antibacterial studies demonstrated a 2.3-fold enhanced potency against Gram-positive bacteria due to their unique peptidoglycan-rich cell wall architecture. These findings collectively establish a microenvironment-adaptive nanoplatform for precision antimicrobial interventions, providing a translational strategy to address drug-resistant infections. Full article

In this study, we report the synthesis and characterization of a novel NH₂-MIL-101(Fe) magnetic composite, developed via in situ formation of NH₂-MIL-101(Fe) in the presence of Fe₃O₄ nanoparticles embedded within a chloropropyl-modified mesoporous silica layer. This hybrid composite retains the high adsorption capacity of NH₂-MIL-101(Fe) while benefiting from the easy magnetic separation enabled by Fe₃O₄ nanoparticles. The mesoporous silica forms a protective porous coating around the magnetic nanoparticles, significantly enhancing its chemical stability and preventing clumping. Beyond protection, the mesoporous silica layer provides a high-surface-area scaffold that promotes the uniform in situ growth of NH₂-MIL-101(Fe). Functionalization of the silica surface with chloride groups enables strong electrostatic interactions between the magnetic component and metal organic framework (MOF), ensuring a homogeneous and stable hybrid structure. The new composite’s capacity to remove Pb(II) and Cd(II) ions from aqueous solutions was systematically investigated. The adsorption data showed a good fit with the Langmuir isotherm model for both ions, the maximum adsorption capacities calculated being 214.6 mg g⁻¹ for Pb(II) and 181.6 mg g⁻¹ Cd(II). Furthermore, the kinetic behavior of the adsorption process was accurately described by the pseudo-second-order model. These findings confirm the effectiveness of this composite for the removal of Pb(II) and Cd(II) ions from aqueous solutions, demonstrating its potential as an efficient material for environmental remediation. The combination of magnetic recovery, high adsorption capacity, and stability makes this novel composite a promising candidate for heavy metal removal applications in water treatment processes. Full article

Iron-based metal–organic frameworks (Fe-MOFs) are promising for biomedical and environmental applications due to their porosity, tunable chemistry, and biocompatibility. This study examines how particle size, morphology, and ligand composition affect the properties and cytotoxicity of MIL-101(Fe) and MIL-88A. MIL-101(Fe) (octahedral) and MIL-88A (rod-like) were synthesized with a controlled size (~200 nm to ~5 μm). Both showed a high crystallinity and stability. Cytotoxicity assays in A549 cells revealed size- and structure-dependent effects: smaller particles of MIL-88A caused greater toxicity (32.5% viability) than MIL-101(Fe) (66.1% viability at 100 μg/mL), while larger particles were less toxic. MIL-88A also induced higher reactive oxidative species (ROS) levels and degraded more rapidly, releasing more Fe ions. Toxicity predication analysis indicated the higher inherent toxicity of MIL-88A’s ligand (fumaric acid) compared to MIL-101(Fe)’s terephthalic acid. These results demonstrate that structural and chemical factors collectively influence Fe-MOFs’ biocompatibility and highlight the importance of rational design for safer MOF applications. Full article

The aim of this study is to investigate a green and efficient hydrothermal synthesis method for obtaining a high-purity MIL-100(Fe) metal–organic framework (MOF) without using hazardous HF acid or other toxic reagents. The influence of various synthesis conditions (reactant ratios and reaction times) and washing protocols on the MOF’s properties and crystallinity was investigated. Additionally, the adsorption capacities of the synthesized MIL-100(Fe) for hydrogen (H₂), carbon dioxide (CO₂), and water vapor were evaluated at different temperatures and pressures. By analyzing the adsorption behavior, this research study aims to assess the potential of this material for thermal or specific gas storage applications. MF-S1 synthesis, using less iron and water, produces the purest MIL-100(Fe), as confirmed by XRD and FTIR. MF-S1-W2, with additional washing, is ideal for gas adsorption due to its crystallinity, purity, and high surface area. It effectively stores hydrogen (0.25 wt.% at 5 °C), CO₂ (32.6 wt.% at 5 °C), and water vapor (47.5 wt.% at 30 °C). Full article

NiFe₂O₄ and TiO₂ are widely studied for photoelectrochemical (PEC) applications due to their unique properties. Nitrogen-doped graphene (NG) and metal–organic frameworks (MOFs), such as MIL-100(Fe) (where MIL stands for Materials of Lavoisier Institute), are commonly incorporated to enhance PEC performance by offering a high surface area and facilitating efficient charge transport. Composite systems are commonly employed to overcome the limitations of individual PEC catalysts. In this study, a highly efficient NiFe₂O₄/NG@MIL-100(Fe)/TiO₂ photoanode was developed to enhance photoelectrochemical water-splitting performance. The composite was synthesized via a hydrothermal method with a two-step heating process. X-ray diffraction confirmed the expected crystal structures, with peak broadening in NiFe₂O₄ indicating reduced crystallite size and increased lattice strain. X-ray photoelectron spectroscopy of the Ni 2p and Fe 2p regions validated the successful integration of NiFe₂O₄ into the composite. Electrochemical analysis demonstrated excellent performance, with linear sweep voltammetry achieving a peak photocurrent density of 3.5 mA cm⁻² at 1.23 V (vs RHE). Electrochemical impedance spectroscopy revealed a reduced charge-transfer resistance of 50 Ω, indicating improved charge transport. Optical and electronic properties were evaluated using UV-Vis spectroscopy and Tauc plots, revealing a direct bandgap of 2.1 eV. The composite exhibited stable photocurrent under amperometric J-t testing for 2000 s, demonstrating its durability. These findings underscore the potential of NiFe₂O₄/NG@MIL-100(Fe)/TiO₂ as a promising material for renewable energy applications, particularly in photoelectrochemical water splitting. Full article

Electrochemical reduction is a promising strategy for the dechlorination of halogenated organic compounds, offering advantages such as enhanced electron transfer efficiency and increased hydrogen atom concentration. It has garnered significant attention for application in mitigating halogenated disinfection by-products (DBPs) in drinking water, owing to its high efficiency and simple operation. In this study, trichloroacetic acid (TCAA), a representative DBP, was selected as the target contaminant. A novel composite cathode comprising a metal–organic framework MIL-53(Fe)@C supported on an Nd magnet (MIL-53(Fe)@C-MAG) and its dechlorination performance for TCAA were systematically investigated. The innovative aspect of this study is the magnetic attachment of the MOF catalyst to the carbonized cathode surface treated through carbonization, which fundamentally differs from conventional solvent-based adhesion methods. Compared to the bare electrode, the MIL-53(Fe)@C-MAG achieved a TCAA removal efficiency exceeding 96.03% within 8 h of contact time. The structural characterization revealed that the α-Fe⁰ crystalline phase serves as the primary active center within the MIL-53(Fe)@C catalyst, facilitating efficient electron transfer and TCAA degradation. The scavenger experiments revealed that TCAA reduction involves a dual pathway: direct electron transfer and atomic hydrogen generation. The modified MIL-53(Fe)@C-MAG electrode exhibited robust electrolytic performance over a broad pH range of 3–7, with TCAA removal efficiency showing a positive correlation with current density within the range of 10–50 mA/cm². Furthermore, the electrode maintained exceptional stability, retaining more than 90% removal efficiency after five consecutive operational cycles. The versatility of the system was further validated by the rapid and efficient dechlorination of various chlorinated DBPs, demonstrating the broad applicability of the electrode. The innovative magnetic composite electrode demonstrates a significant advancement in electrochemical dechlorination technology, offering a reliable and efficient solution for the purification of drinking water contaminated with diverse halogenated DBPs. These results provide valuable insights into the development of electrolysis for dechlorination in water treatment applications. Full article

The third-generation semiconductor single-crystal silicon carbide (SiC), as a typical difficult-to-machine material, improves the chemical reaction rate on the SiC surface during the polishing process, which is key to realizing efficient chemical mechanical polishing (CMP). In this paper, a new core-shell structure Fe₃O₄@MIL-100(Fe) magnetic catalyst was successfully synthesized, which can effectively improve the reaction rate during the SiC polishing procesSs. The catalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), and was used as a heterogeneous photocatalyst for chemical mechanical polishing, and the polishing results of SiC were optimized using response surface methodology (RSM). The experimental results show that the surface roughness of SiC can reach the minimum value of 0.78 nm when the polishing pressure is 0.06 MPa, the polishing speed is 60 rpm, and the polishing flow rate is 12 mL/min. The results of the study provide theoretical support for the visible photocatalysis-assisted CMP of SiC. Full article

This study successfully prepared MIL-101(Fe)@MoS₂ composite photocatalysts via hydrothermal methods to address the efficient removal of refractory organic dyes in dye wastewater. Characterization using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) confirmed that molybdenum disulfide (MoS₂) was uniformly loaded onto the surface of MIL-101(Fe), forming a heterojunction that significantly enhanced light absorption capacity and charge separation efficiency. In a visible-light-driven photo-Fenton system, this material exhibited excellent degradation performance for Congo red (CR). At an initial CR concentration of 50 mg/L, a catalyst dosage of 0.2 g/L, 4 mL of added H₂O₂, and pH 7, CR was completely degraded within 30 min, with the total organic carbon (TOC) removal reaching 72.5%. The material maintained high degradation efficiency (>90%) across a pH range of 3–9, overcoming the traditional Fenton system’s dependency on acidic media. Radical-trapping experiments indicated that superoxide radicals (·O₂⁻) and photogenerated holes (·h⁺) were the primary active species responsible for degradation, revealing a synergistic catalytic mechanism at the heterojunction interface. Recyclability tests showed that the material retained 90.8% degradation efficiency after five cycles, and an X-ray photoelectron spectroscopy (XPS) analysis demonstrated the stable binding of Fe and Mo, preventing secondary pollution. This study provides a scientific basis for developing efficient, stable, and wide-pH adaptable photo-Fenton catalytic systems, contributing significantly to the advancement of green water treatment technologies. Full article

The continuous increase in global energy consumption has caused a considerable increase in CO₂ emissions and environmental problems. To address these challenges, adsorbents and catalytic materials that can effectively reduce the CO₂ levels in the atmosphere should be developed. Metal–organic frameworks (MOFs) have emerged as promising materials for CO₂ capture owing to their high surface areas and tunable structures. Herein, the CO₂ adsorption properties of MIL-100(Fe) and UiO-66(Zr) were investigated. Both MOFs exhibited excellent thermal stability and high CO₂ adsorption capacities at 300 K, and they maintained good adsorption properties at 500 K compared to those of activated carbon fiber owing to their high adsorption potentials. A slight change in the UiO-66(Zr) structure and no change in the MIL-100(Fe) structure were observed under the CO₂ atmosphere at 500 K. At that time, CO emissions and changes in the carboxyl and OCO functional groups were observed on MIL-100(Fe), suggesting a mechanism of CO₂ reduction to CO on the bare Fe(II) sites. These findings confirm the potential of MOFs for the thermo-catalytic reduction of CO₂ to achieve effective CO₂ capture and conversion. Full article

With the rapid increase in polyethylene terephthalate (PET) usage in recent years, recycling has become indispensable in mitigating environmental damage and safeguarding natural resources. In this context, this study presents a methodology for valorizing PET waste through phase transfer catalytic hydrolysis conducted at a low temperature (80 °C) and atmospheric pressure, with the goal of recovering the terephthalic acid (TPA) monomer. The recovered TPA monomer was subsequently utilized as a precursor for the synthesis of metal–organic frameworks (MOFs). Tributylhexadecyl phosphonium bromide (3Bu6DPB) was selected as the phase transfer catalyst due to its efficiency and sustainability. The process parameters, including the concentration of NaOH, the wt.% of catalyst to PET, and the concentration of PET in the solution, were varied to optimize the hydrolysis reaction. The Taguchi design methodology with an L9 (3^3) orthogonal array was employed to analyze the influence of these factors on the depolymerization time. The analysis of variance (ANOVA) results revealed that the concentration of NaOH was the most significant factor, contributing to 93.3% of the process efficiency, followed by the wt.% of the catalyst to PET (6.5%). The findings also demonstrated that the concentration of NaOH had the greatest impact (Δ = 4.27, rank = 1), while the concentration of PET had the smallest effect (Δ = 0.16, rank = 3). The optimal conditions for PET depolymerization were achieved in 75 min with 20 g/100 mL of NaOH, 12 wt.% of catalyst to PET, and 5 g/100 mL of PET. The recovered TPA monomer was further employed as an organic ligand to synthesize Fe(III)-TPA MOFs under mild conditions (80 °C for 24 h). The X-ray diffraction (XRD) analysis revealed the simultaneous formation of MOF-235(Fe) and MIL-101(Fe), two multifunctional materials with diverse properties and applications. This study highlights an efficient approach for producing low-cost MOFs while promoting urban waste recycling, contributing to an integrated strategy for PET recycling and resource valorization. Full article

Idesia polycarpa Maxim. is a woody oil crop with great potential for edible oil production. While crude oil is rich in pigments, traditional bleaching methods have limited effectiveness in improving its color. In this study, a metal-organic framework (MOF) material, MIL-88B(Fe), was synthesized and used for the bleaching of Idesia polycarpa Maxim. oil. The adsorption selectivity of MIL-88B(Fe) and the adsorption process of carotenoids and chlorophyll were investigated. The results demonstrated that the synthesized MIL-88B(Fe) exhibited excellent bleaching capability, achieving a bleaching rate of 97.67% in 65 min. It showed a strong adsorption effect on pigments, particularly carotenoids. The content of lutein decreased from 118.27 mg/kg to 0.01 mg/kg after 65 min of bleaching. The squalene and phytosterol contents in the oil were minimally affected by the bleaching process, while the free fatty acid content slightly increased due to the high reaction temperature and the adsorbent properties. The adsorption process of MIL-88B(Fe) was best described by a pseudo-first-order kinetic model, indicating that the adsorption was a spontaneous and endothermic chemical process. Moreover, MIL-88B(Fe) demonstrated good safety and reusability, making it a promising novel adsorbent for the bleaching of Idesia polycarpa Maxim. oil and other oils with a high pigment content for the vegetable oil industry. Full article