Synthesis, Characterization of [Co(BDC)(Phen)H2O] and [Co(BDC)(DABCO)] MOFs, π..π Interactions, Hirshfeld Surface Analysis and Biological Activity

DFT study of free radical scavenging mechanisms in UiO-66-(OH)2 and UiO-66-NH2 MOFs

This study employs density functional theory (DFT) to investigate three common free radical scavenging mechanisms (hydrogen atom transfer (HAT), single electron transfer proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET)) in UiO-66-(OH)2 and UiO-66-NH2 metal-organic framework (MOF) nanoparticles under gas, benzene and aqueous phase conditions. The reaction processes between UiO-66-(OH)2/UiO-66-NH2 and hydroxyl radicals (˙OH) were simulated to elucidate detailed radical capture pathways, and the computational results were validated by macroscopic DPPH radical scavenging experiments. The results indicate that: (1) among the three mechanisms, HAT consistently exhibits the lowest bond dissociation energy across all phases, suggesting MOF nanoparticles preferentially undergo hydrogen atom transfer over electron transfer during radical scavenging; (2) compared to gas phase and nonpolar solvent (benzene), polar solvent (water) significantly lowers the energy barriers for both electron transfer and hydrogen transfer, thus enhancing reactivity across all mechanisms; (3) UiO-66-(OH)2 exhibits a radical scavenging rate constant of 1.0 × 109 M-1 s-1, higher than 7.63 × 108 M-1 s-1 for UiO-66-NH2; (4) DPPH assays reveal that UiO-66-(OH)2 exhibits an 8% greater radical scavenging efficiency than UiO-66-NH2, in agreement with DFT predictions and confirming the antioxidative benefit of hydroxyl functionalization. This study proposes a combined DFT and experimental screening workflow for radical scavengers, offering an efficient and economical approach to rapidly identify novel MOF-based radioprotective radical scavengers.

Nuclease-Mimetic Nanomaterials: From Fundamentals to Bioapplications

With the rapid development of nanozymes and nanomedicine, designing novel nanostructures directly acting on deoxyribonucleic acid (DNA) has great therapeutic potential because DNA is the carrier of genetic information and plays a vital role on life activities of the organism. Specifically, DNA cleavage is an important step in most of these DNA engineering technologies. While nucleases play crucial roles in the cell metabolism by efficient DNA cutting, the practical applications of natural nucleases suffer from some intrinsic shortcomings such as high cost and intolerance to harsh environments. In the past 20 years, great varieties of engineered nanostructures with DNA cleavage (nuclease-mimetic nanomaterials, abbreviated as nuclease mimics) have been developed rapidly and widely used in biomedical fields. In view of the significant progress of nuclease-mimetic nanomaterials, the possible DNA cleavage mechanism mediated by nuclease-mimetic nanomaterials is systematically discussed in this review, and the classification of nuclease-mimetic nanomaterials is illustrated. Their potential biomedical applications, especially in anti-biofilms and cancer treatment, are also comprehensively summarized. Finally, the current opportunities and challenges are discussed to stimulate the research of understanding and development of nuclease-mimetic nanomaterials.

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.

Revolutionizing environmental cleanup: the evolution of MOFs as catalysts for pollution remediation

The global problem of ecological safety and public health necessitates, the development of new sustainable ideas for pollution remediation. In recent development, metal-organic frameworks (MOF) are the emerging technology with remarkable potential, which have been employed in environmental remediation. MOFs are networks that are created by the coordination of metals or polyanions with ligands and contain organic components that can be customized. The interesting features of MOFs are a large surface area, tuneable porosity, functional diversity, and high predictability of pollutant adsorption, catalysis, and degradation. It is a solid material that occupies a unique position in the war against environmental pollutants. One of the main benefits of MOFs is that they exhibit selective adsorption of a wide range of pollutants, including heavy metals, organics, greenhouse gases, water and soil. Only particles with the right combination of pore size and chemical composition will achieve this selectivity, derived from the high level of specificity. Besides, they possess high catalytic ability for the removal of pollutants by means of different methods such as photocatalysis, Fenton-like reactions, and oxidative degradation. By generating mobile active sites within the framework of MOFs, we can not only ensure high affinity for pollutants but also effective transformation of toxic chemicals into less harmful or even inert end products. However, the long-term stability of MOFs is becoming more important as eco-friendly parts are replaced with those that can be used repeatedly, and systems based on MOFs that can remove pollutants in more than one way are fabricated. MOFs can reduce waste production, energy consumption as compared to the other removal process. With its endless capacities, MOF technology brings a solution to the environmental cleansing problem, working as a flexible problem solver from one field to another. The investigation of MOF synthesis and principles will allow researchers to fully understand the potential of MOFs in environmental problem solving, making the world a better place for all of us.

Novel Tannic Acid-Modified Cobalt-Based Metal-Organic Framework: Synthesis, Characterization, and Antimicrobial Activity

Metal-organic frameworks (MOFs) are a class of hybrid inorganic-organic materials with typical porous structures and a unique morphology. Due to their diversity, they are extensively used in a wide range of applications such as environmental, catalysis, biomedicine, etc. In this study, a novel cobalt-based MOF modified with tannic acid (Co-TPA/TA) (TPA: terephthalic acid; TA: tannic acid) as a promising material for antimicrobial agents was synthesized and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, inductively coupled plasma-optical emission spectrometry, and thermogravimetric analysis and compared with an as-synthesized cobalt-based framework. Co-TPA/TA demonstrated good antimicrobial efficiency under optimum conditions against yeast Candida albicans ATCC 10231, Gram-negative Escherichia coli ATCC 8739, and Gram-positive Staphylococcus aureus ATCC 6538 with an inhibition zone ranging from 14 to 20 mm. Reduced ATP levels, generation of reactive oxygen species, membrane damage from cobalt ion release, and development of an alkaline microenvironment could all be contributing factors to the possible antimicrobial pathways. The novel framework can be obtained using simple, affordable, and easily accessible commercial ligands and is considered to have the potential to be used as an antimicrobial material in the future.

Current status and prospects of MIL-based MOF materials for biomedicine applications

This article mainly reviews the biomedicine applications of two metal-organic frameworks (MOFs), MIL-100(Fe) and MIL-101(Fe). These MOFs have advantages such as high specific surface area, adjustable pore size, and chemical stability, which make them widely used in drug delivery systems. The article first introduces the properties of these two materials and then discusses their applications in drug transport, antibacterial therapy, and cancer treatment. In cancer treatment, drug delivery systems based on MIL-100(Fe) and MIL-101(Fe) have made significant progress in chemotherapy (CT), chemodynamic therapy (CDT), photothermal therapy (PTT), photodynamic therapy (PDT), immunotherapy (IT), nano-enzyme therapy, and related combined therapy. Overall, these MIL-100(Fe) and MIL-101(Fe) materials have tremendous potential and diverse applications in the field of biomedicine.