Ag@MUT-16 nanocomposite as a Fenton-like and plasmonic photocatalyst for degradation of Quinoline Yellow under visible light

A new cobalt-based metal-organic framework with the chemical formula of [Co2(DClTPA)2(DABCO)]·(DMF)4 (MUT-16) containing 1,4-diazabicyclo[2.2.2]octane (DABCO) and 2,5-dichloroterephthalic acid (DClTPA) has been designed and prepared through a solvothermal method. MUT-16 (MUT = Materials from University of Tehran) crystallized in a tetragonal system with I41/acd space group, based on single-crystal X-ray analysis. The Ag@MUT-16 nanocomposite was prepared using Ag nanoparticles (NPs) loaded into/onto porous MUT-16via photoreduction route (PR). The MUT-16 and Ag@MUT-16 were characterized using various techniques, such as PXRD, FT-IR, FE-SEM, TEM, EDX, N2 adsorption-desorption isotherms, TGA, DRS, PL, EIS, and Mott-Schottky measurements. The Ag@MUT-16 nanocomposite showed photocatalytic activity of 87.75% in the degradation of Quinoline Yellow (QY) after 30 min under visible light irradiation. The distinctive characteristics of the Ag@MUT-16 nanocomposite, such as the Fenton-like effect of Co2+ ions, surface plasmon resonance (SPR) of Ag NPs, Schottky junction at interfaces between Ag NPs and MUT-16, and reduction of electron-hole recombination through electron trapping by Ag NPs as co-catalyst, all play significant roles in the photocatalytic degradation of Quinoline Yellow (QY).

Recent advances and potential applications for metal-organic framework (MOFs) and MOFs-derived materials: Characterizations and antimicrobial activities

Microbial infections, particularly those caused by antibiotic-resistant pathogens, pose a critical global health threat. Metal-Organic Frameworks (MOFs), porous crystalline structures built from metal ions and organic linkers, initially developed for gas adsorption, have emerged as promising alternatives to traditional antibiotics. This review, covering research up to 2023, explores the potential of MOFs and MOF-based materials as broad-spectrum antimicrobial agents against bacteria, viruses, fungi, and even parasites. It delves into the historical context of antimicrobial agents, recent advancements in MOF research, and the diverse synthesis techniques employed for their production. Furthermore, the review comprehensively analyzes the mechanisms of action by which MOFs combat various microbial threats. By highlighting the vast potential of MOFs, their diverse synthesis methods, and their effectiveness against various pathogens, this study underscores their potential as a novel solution to the growing challenge of antibiotic resistance.

Magnetic UiO-66-NH2 Core-Shell Nanohybrid as a Promising Carrier for Quercetin Targeted Delivery toward Human Breast Cancer Cells

In this study, a magnetic core-shell metal-organic framework (MOF) nanocomposite, Fe3O4-COOH@UiO-66-NH2, was synthesized for tumor-targeting drug delivery by incorporating carboxylate groups as functional groups onto ferrite nanoparticle surfaces, followed by fabrication of the UiO-66-NH2 shell using a facile self-assembly approach. The anticancer drug quercetin (QU) was loaded into the magnetic core-shell nanoparticles. The synthesized magnetic nanoparticles were comprehensively evaluated through multiple techniques, including FT-IR, PXRD, FE-SEM, TEM, EDX, BET, UV-vis, ZP, and VSM. Drug release investigations were conducted to investigate the release behavior of QU from the nanocomposite at two different pH values (7.4 and 5.4). The results revealed that QU@Fe3O4-COOH@UiO-66-NH2 exhibited a high loading capacity of 43.1% and pH-dependent release behavior, maintaining sustained release characteristics over a prolonged duration of 11 days. Furthermore, cytotoxicity assays using the human breast cancer cell line MDA-MB-231 and the normal cell line HEK-293 were performed to evaluate the cytotoxic effects of QU, UiO-66-NH2, Fe3O4-COOH, Fe3O4-COOH@UiO-66-NH2, and QU@Fe3O4-COOH@UiO-66-NH2. Treatment with QU@Fe3O4-COOH@UiO-66-NH2 substantially reduced the cell viability in cancerous MDA-MB-231 cells. Cellular uptake and cell death mechanisms were further investigated, demonstrating the internalization of QU@Fe3O4-COOH@UiO-66-NH2 by cancer cells and the induction of cancer cell death through the apoptosis pathway. These findings highlight the considerable potential of Fe3O4-COOH@UiO-66-NH2 as a targeted nanocarrier for the delivery of anticancer drugs.

Engineered Catalyst Based on MIL-68(Al) with High Stability for Hydrogenation of Carbon Dioxide and Carbon Monoxide at Low Temperature

Today, the importance of decreasing and converting COx gases from the atmosphere into value-added chemicals by catalytic hydrogenation reactions has become one crucial challenge. In the current work, to facilitate the hydrogenation of COx, several mesoporous alumina catalysts with high efficiency and stability were synthesized using the MIL-68(Al) platform, a nanoporous MOF with a high surface area as a precatalyst, encapsulating nickel or nickel-iron nanoparticles (NPs). After removing the organic linker of MIL-68(Al) by calcination in air, two types of catalysts, promoted and unpromoted, were obtained with various loads of nickel and iron. A set of analyses (PXRD, BET-N2, TEM, FE-SEM, ICP-OES, EDX-map, CO2-TPD, H2-TPR, and H2-TPD) were performed to evaluate the physicochemical properties of catalysts. Based on the analysis results, the promoted catalyst had smaller particles and pores due to the effective and uniform distribution of nickel NPs. Also, H2-TPR and CO2-TPD results in samples containing Fe promoter demonstrated the facilitation of the reduction process and the adsorption and activation of CO2, respectively. The results of CO2 methanation indicated an improved catalytic performance for promoted samples, especially at low temperatures (200-300 °C), compared to unpromoted catalysts. 5Fe·15Ni@Al2O3 MIL-68(Al) catalyst displayed the best performance compared to other catalysts, with a conversion of 92.4% and selectivity of 99.6% at 350 °C and GHSV = 2500 h-1. Moreover, the 5Fe·15Ni@Al2O3 MIL-68(Al) catalyst facilitated the CO2 methanation reaction by reducing the activation energy to 42.5 kJ mol-1 compared with other reported catalysts. Both types of catalysts performed 100% hydrogenation of CO to CH4 with full selectivity at 250 °C and exhibited high stability for at least 100 h at 300 °C. Notably, such high significant catalytic performance is only achieved by the usage of the "MOFs templating strategy" due to the high surface area for the effective distribution of NPs, the strong metal-support interaction, and the formation of nickel aluminate species, preventing the sintering of NPs.

Flexible Curcumin-Loaded Zn-MOF Hydrogel for Long-Term Drug Release and Antibacterial Activities

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sectors. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes with antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings, such as poor water solubility, poor chemical stability, and fast metabolic rate, limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to their biomimetic structure, soft porous microarchitecture, and favorable biomechanical properties. The drug loading/releasing efficiencies can also be controlled via using highly crystalline and porous metal-organic frameworks (MOFs). Herein, a flexible hydrogel composed of a sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Raman spectroscopy, and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to comply with human skin mechanically. The as-prepared hydrogel could capture efficient CCM for slow drug release and effectively kill bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings.

Metal-Organic Frameworks and Their Biodegradable Composites for Controlled Delivery of Antimicrobial Drugs

Antimicrobial resistance (AMR) is a growing global crisis with an increasing number of untreatable or exceedingly difficult-to-treat bacterial infections, due to their growing resistance to existing drugs. It is predicted that AMR will be the leading cause of death by 2050. In addition to ongoing efforts on preventive strategies and infection control, there is ongoing research towards the development of novel vaccines, antimicrobial agents, and optimised diagnostic practices to address AMR. However, developing new therapeutic agents and medicines can be a lengthy process. Therefore, there is a parallel ongoing worldwide effort to develop materials for optimised drug delivery to improve efficacy and minimise AMR. Examples of such materials include functionalisation of surfaces so that they can become self-disinfecting or non-fouling, and the development of nanoparticles with promising antimicrobial properties attributed to their ability to damage numerous essential components of pathogens. A relatively new class of materials, metal-organic frameworks (MOFs), is also being investigated for their ability to act as carriers of antimicrobial agents, because of their ultrahigh porosity and modular structures, which can be engineered to control the delivery mechanism of loaded drugs. Biodegradable polymers have also been found to show promising applications as antimicrobial carriers; and, recently, several studies have been reported on delivery of antimicrobial drugs using composites of MOF and biodegradable polymers. This review article reflects on MOFs and polymer-MOF composites, as carriers and delivery agents of antimicrobial drugs, that have been studied recently, and provides an overview of the state of the art in this highly topical area of research.

Porous organic polymers for drug delivery: hierarchical pore structures, variable morphologies, and biological properties

Porous organic polymers have received considerable attention in recent years because of their applicability as biomaterials. In particular, their hierarchical pore structures, variable morphologies, and tunable biological properties make them suitable as drug-delivery systems. In this review, the synthetic and post forming/control methods including templated methods, template-free methods, mechanical methods, electrospun methods, and 3D printing methods for controlling the hierarchical structures and morphologies of porous organic polymers are discussed, and the different methods affecting their specific surface areas, hierarchical structures, and unique morphologies are highlighted in detail. In addition, we discuss their applications in drug encapsulation and the development of stimuli (pH, heat, light, and dual-stimuli)-responsive materials, focusing on their use for targeted drug release and as therapeutic agents. Finally, we present an outlook concerning the research directions and applications of porous polymer-based drug delivery systems.

Embedding an extraordinary amount of gemifloxacin antibiotic in ZIF-8 framework with one-step synthesis and measurement of its H2O2-sensitive release and potency against infectious bacteria

GEM@ZIF-8 has DLC = 69.82% and DLE = 89.03%, with controlled release dependent on H2O2 concentration, and it shows significant antibacterial activity.

Recovery of syringic acid from aqueous solution by magnetic Fe–Zn/ZIF and its slow release from the CA-coated carrier based on the 3Rs concept

The excessive utilization of syringic acid (SA) has caused severe environmental pollution and economic waste.