Synthesis, characterization, crystal structure and antimicrobial studies of a novel Cu(II) complex based on itaconic acid and nicotinamide

Multifunctional metal-organic frameworks as promising nanomaterials for antimicrobial strategies

Bacterial infections pose a serious threat to human health. While antibiotics have been effective in treating bacterial infectious diseases, antibiotic resistance significantly reduces their effectiveness. Therefore, it is crucial to develop new and effective antimicrobial strategies. Metal-organic frameworks (MOFs) have become ideal nanomaterials for various antimicrobial applications due to their crystalline porous structure, tunable size, good mechanical stability, large surface area, and chemical stability. Importantly, the performance of MOFs can be adjusted by changing the synthesis steps and conditions. Pure MOFs can release metal ions to modulate cellular behaviors and kill various microorganisms. Additionally, MOFs can act as carriers for delivering antimicrobial agents in a desired manner. Importantly, the performance of MOFs can be adjusted by changing the synthesis steps and conditions. Furthermore, certain types of MOFs can be combined with traditional photothermal or other physical stimuli to achieve broad-spectrum antimicrobial activity. Recently an increasing number of researchers have conducted many studies on applying various MOFs for diseases caused by bacterial infections. Based on this, we perform this study to report the current status of MOF-based antimicrobial strategy. In addition, we also discussed some challenges that MOFs currently face in biomedical applications, such as biocompatibility and controlled release capabilities. Although these challenges currently limit their widespread use, we believe that with further research and development, new MOFs with higher biocompatibility and targeting capabilities can provide diversified treatment strategies for various diseases caused by bacterial infections.

Functionalization of a porous copper(ii) metal-organic framework and its capacity for loading and delivery of ibuprofen

A porous copper(ii) metal-organic framework (MOF) of 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine(N3ttb) and 5-nitroisophthalic acid (npd) formulated as [Cu(npd)(N3ttb)]·(DMF)(H2O) 1 (DMF = dimethylformamide) was synthesized and characterized by elemental analyses, spectroscopic techniques, single crystal X-ray crystallography, and scanning electron microscopy. Single crystal X-ray crystallographic analysis of the copper(ii) metal-organic framework reveals a monoclinic crystal system with space group P21/c. The copper(ii) ion is in a five-coordinate geometry consisting of three meridional nitrogen atoms of 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine and two oxygen atoms of 5-nitroisophthalic acid to form a square pyramidal structure. The compound was functionalized with ethylenediamine (ED) to form [Cu(npd)(N3ttb)]-ED 2 that was characterized by FT-IR, PXRD, SEM-EDX and BET and the drug loading capacity was investigated and compared with that of as-synthesized MOFs. The amount of ibuprofen loaded was 916.44 mg g-1 (15.27%) & 1530.20 mg g-1 (25.50%) over 1 and 2, respectively. The results indicate that the functionalized MOFs 2 have a higher loading capacity for ibuprofen than 1 by 613.76 mg g-1 (10.23%), which could be ascribed to the acid-base interactions in the functionalized molecules. The results show that [Cu(npd)(N3ttb)]-ED 2 is a better drug transporter than [Cu(npd)(N3ttb)]·(DMF)(H2O) 1 due to the presence of an amine functional group that interacts with the acid group on the ibuprofen through non-covalent bonds interactions.

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.

Metal-Organic-Framework-Based Materials for Antimicrobial Applications

To address the serious threat of bacterial infection to public health, great efforts have been devoted to the development of antimicrobial agents for inhibiting bacterial growth, preventing biofilm formation, and sterilization. Very recently, metal-organic frameworks (MOFs) have emerged as promising materials for various antimicrobial applications owing to their different functions including the controlled/stimulated decomposition of components with bactericidal activity, strong interactions with bacterial membranes, and formation of photogenerated reactive oxygen species (ROS) as well as high loading and sustained releasing capacities for other antimicrobial materials. This review focuses on recent advances in the design, synthesis, and antimicrobial applications of MOF-based materials, which are classified by their roles as component-releasing (metal ions, ligands, or both), photocatalytic, and chelation antimicrobial agents as well as carriers or/and synergistic antimicrobial agents of other functional materials (antibiotics, enzymes, metals/metal oxides, carbon materials, etc.). The constituents, fundamental antimicrobial mechanisms, and evaluation of antimicrobial activities of these materials are highlighted to present the design principles of efficient MOF-based antimicrobial materials. The prospects and challenges in this research field are proposed.

A new one-dimensional CuII complex with a three-dimensional supramolecular architecture incorporating benzene-1,3-dicarboxylate and 1-[(1H-benzotriazol-1-yl)methyl]-1H-imidazole

Subtle modifications of N-donor ligands can result in complexes with very different compositions and architectures. In the complex catena-poly[[bis{1-[(1H-benzotriazol-1-yl)methyl]-1H-imidazole-κN³}copper(II)]-μ-benzene-1,3-dicarboxylato-κ³O¹,O^1':O³], {[Cu(C₈H₄O₄)(C₁₀H₉N₅)₂(H₂O)]·2H₂O}_n, each Cu^II ion is six-coordinated by two N atoms from two crystallographically independent 1-[(1H-benzotriazol-1-yl)methyl]-1H-imidazole (bmi) ligands, by three O atoms from two symmetry-related benzene-1,3-dicarboxylate (bdic^2-) ligands and by one water molecule, leading to a distorted CuN₂O₄ octahedral coordination environment. The Cu^II ions are connected by bridging bdic^2- anions to generate a one-dimensional chain. The bmi ligands coordinate to the Cu^II ions in monodentate modes and are pendant on opposite sides of the main chain. In the crystal, the chains are linked by O-H...O and O-H...N hydrogen bonds, as well as by π-π interactions, into a three-dimensional network. A thermogravimetric analysis was carried out and the fluorescence behaviour of the complex was also investigated.