A metal-organic framework MIL-53(Fe) containing sliver ions with antibacterial property

Research progress on antibacterial applications of metal-organic frameworks and their biomacromolecule composites

With the extensive use of antibiotics, resulting in increasingly serious problems of bacterial resistance, antimicrobial therapy has become a global concern. Metal-organic frameworks (MOFs) are low-density porous coordination materials composed of metal ions and organic ligands, which can form composite materials with biomacromolecules such as proteins and polysaccharides. In recent years, MOFs and their derivatives have been widely used in the antibacterial field as efficient antibacterial agents. This review offers a detailed summary of the antibacterial applications of MOFs and their composites, and the different synthesis methods and antibacterial mechanisms of MOFs and MOF-based composites are briefly introduced. Finally, the challenges and prospects of MOFs-based antibacterial materials in the rapidly developing medical field were briefly discussed. We hope this review will provide new strategies for the medical application of MOFs-based antibacterial materials.

A Cu-Based Metal-Organic Framework Cu-Cip with Cuproptosis for Cancer Therapy and Inhibition of Cancer Cell Migration

Microflora within cancer cells plays a pivotal role in promoting metastasis of cancer. However, contemporary anticancer research often overlooks the potential benefits of combining anticancer and antibacterial agents. Consequently, a metal-organic framework Cu-Cip with cuproptosis and antibacterial properties was synthesized for cancer therapy. To enhance the anticancer effect of the material, Mn2+ was loaded into Cu-Cip, yielding Mn@Cu-Cip. The fabricated material was characterized using single-crystal X-ray diffraction, PXRD, and FT-IR. By interacting with overexpressed H2O2 to produce ROS and accumulating Cu ions in cancer cells, MOFs exhibited excellent anticancer performance. Moreover, the material displayed the function of damaging Staphylococcus aureus and Escherichia coli, revealing the admirable antibacterial properties of the material. In addition, the antibacterial ability could inhibit tumor cell migration. The Cu-based MOF revealed promising applications in the field of tumor treatment.

Dual-Mechanism Tuned Engineered Polyphenols with Cascade Photocatalytic Self-Fenton Reaction for Sustainable Biocidal Coatings

Traditional disposable personal protective equipment (PPE) only blocks pathogenic bacteria by mechanical filtration, with the risk of recontamination and transmission remaining. Herein, inspired by phenolic-enabled nanotechnology (PEN), we proposed engineered polyphenol coatings by plant-derived aromatic aldehydes and metal involvement, denoted as FQM, to obtain the desired photocatalysis-self-Fenton antibacterial performance. Experiments and theoretical analysis proved the dual mechanism of Fe-induced enhancement: (1) tuning of molecular structure realized improved optical properties; (2) Fe(III)/Fe(II) triggered photocatalytic cascade self-Fenton reaction. Mechanism study reveals FQM killing bacteria by direct-contact ROS attack and gene regulation. Further, the FQM was developed as the ideal antibacterial coating on different fabrics (cloth cotton, polyester, and N95 mask), killing more than 93% of bacteria after 5 cycles of use. Such photocatalysis-self-Fenton coatings based on engineered polyphenols endowed with desirable safety, sustainability, and efficient antibacterial features are promising solutions to meet the challenges of the currently available PPE.

Application and Development Prospect of Nanoscale Iron Based Metal-Organic Frameworks in Biomedicine

Metal-organic frameworks (MOFs) are coordination polymers that comprise metal ions/clusters and organic ligands. MOFs have been extensively employed in different fields (eg, gas adsorption, energy storage, chemical separation, catalysis, and sensing) for their versatility, high porosity, and adjustable geometry. To be specific, Fe2+/Fe3+ exhibits unique redox chemistry, photochemical and electrical properties, as well as catalytic activity. Fe-based MOFs have been widely investigated in numerous biomedical fields over the past few years. In this study, the key index requirements of Fe-MOF materials in the biomedical field are summarized, and a conclusion is drawn in terms of the latest application progress, development prospects, and future challenges of Fe-based MOFs as drug delivery systems, antibacterial therapeutics, biocatalysts, imaging agents, and biosensors in the biomedical field.

Superhydrophilic quaternized calcium alginate based aerogel membrane for oil-water separation and removal of bacteria and dyes

In recent years, frequent oil spills and increasing industrial wastewater discharge have caused serious water pollution problems. In addition, there are often microbial and dye pollutants in oil-containing wastewater. The development of materials that can simultaneously treat these three pollutants is very important for the safe treatment and recovery of wastewater. In this work, a modified calcium alginate-based aerogel membrane (CTW) was prepared through sol spraying, Ca²⁺ crosslinking and freeze drying by using tetrabutylammonium hydroxide (TBA) quaternary ammonium salt modified sodium alginate (SA) as raw material and waterborne polyurethane (WPU) as adhesive. The results show that CTW membrane has super hydrophilic and underwater super-oleophobic properties, and can realize the separation oil-water emulsions under gravity, with the separation efficiency of >99 %. CTW membrane can also remove bacteria and dye such as Congo red from water by filtration, with removal rates of 100 % and 99 % respectively. The filtration results of mixed wastewater show that CTW membrane can realize one-step separation of oil, bacteria and dye in wastewater, and can also be recycled, having potential application prospect.

Co-doped Fe-MIL-100 as an adsorbent for tetracycline removal from aqueous solution

In the study, Fe-MIL-100 was modified by adding Co²⁺ in the synthesis process; Co/Fe-MIL-100 was successfully synthesized and used to adsorb tetracycline. The addition of Co²⁺ increased the thermal stability of Fe-MIL-100 without changing the crystal structure. It was found that Co/Fe-MIL-100 exhibited satisfactory performance in tetracycline removal, the tetracycline removal efficiency reached almost 100% in the initial concentration range of 10-40 mg/L, and it still reached 82.38% under the condition of 60 mg/L tetracycline. Besides, the factors of tetracycline concentration, pH and inorganic anion on removal efficiency were explored. The coexistence of inorganic anion decreased the adsorption capacity of tetracycline due to the competitive adsorption. CO₃^2- had a more obvious inhibition effect on the adsorption efficiency of tetracycline than Cl^-. The fitting correlation coefficient of Langmuir model was higher and the kinetics better fitted by pseudo-second-order, respectively. As a result of its high removal efficiency and excellent recycling performance, it has great potential in application fields such as removing tetracycline from wastewater.

MIL-101 (Fe) @Ag Rapid Synergistic Antimicrobial and Biosafety Evaluation of Nanomaterials

Metal-organic frameworks (MOFs), which have become popular in recent years as excellent carriers of drugs and biomimetic materials, have provided new research ideas for fighting pathogenic bacterial infections. Although various antimicrobial metal ions can be added to MOFs with physical methods, such as impregnation, to inhibit bacterial multiplication, this is inefficient and has many problems, such as an uneven distribution of antimicrobial ions in the MOF and the need for the simultaneous addition of large doses of metal ions. Here, we report on the use of MIL-101(Fe)@Ag with efficient metal-ion release and strong antimicrobial efficiency for co-sterilization. Fe-based MIL-101(Fe) was synthesized, and then Ag+ was uniformly introduced into the MOF by the substitution of Ag+ for Fe3+. Scanning electron microscopy, powder X-ray diffraction (PXRD) Fourier transform infrared spectroscopy, and thermogravimetric analysis were used to investigate the synthesized MIL-101(Fe)@Ag. The characteristic peaks of MIL-101(Fe) and silver ions could be clearly seen in the PXRD pattern. Comparing the diffraction peaks of the simulated PXRD patterns clearly showed that MIL-101(Fe) was successfully constructed and silver ions were successfully loaded into MIL-101(Fe) to synthesize an MOF with a bimetallic structure, that is, the target product MIL-101(Fe)@Ag. The antibacterial mechanism of the MOF material was also investigated. MIL-101(Fe)@Ag exhibited low cytotoxicity, so it has potential applications in the biological field. Overall, MIL-101(Fe)@Ag is an easily fabricated structurally engineered nanocomposite with broad-spectrum bactericidal activity.

Recent advances in metal-organic framework-based materials for anti-staphylococcus aureus infection

The rapid spread of staphylococcus aureus (S. aureus) causes an increased morbidity and mortality, as well as great economic losses in the world. Anti-S. aureus infection becomes a major challenge for clinicians and nursing professionals to address drug resistance. Hence, it is urgent to explore high efficiency, low toxicity, and environmental-friendly methods against S. aureus. Metal-organic frameworks (MOFs) represent great potential in treating S. aureus infection due to the unique features of MOFs including tunable chemical constitute, open crystalline structure, and high specific surface area. Especially, these properties endow MOF-based materials outstanding antibacterial effect, which can be mainly attributed to the continuously released active components and the exerted catalytic activity to fight bacterial infection. Herein, the structural characteristics of MOFs and evaluation method of antimicrobial activity are briefly summarized. Then we systematically give an overview on their recent progress on antibacterial mechanisms, metal ion sustained-release system, controlled delivery system, catalytic system, and energy conversion system based on MOF materials. Finally, suggestions and direction for future research to develop and mechanism understand MOF-based materials are discussed in antibacterial application.