Antibacterial Cu or Zn-MOFs Based on the 1,3,5-Tris-(styryl)benzene Tricarboxylate

A new MOF@bioactive glass composite reinforced with silver nanoparticles - a new approach to designing antibacterial biomaterials

Multifunctional materials that combine antimicrobial properties with the ability to stimulate bone formation are needed to overcome the problem of infected bone defects. As a novel approach, a new composite based on bioactive glass nanoparticles in a simple system of SiO2-CaO (BG) coated with NH4[Cu3(μ3-OH)(μ3-4-carboxypyrazolato)3] (Cu-MOF) with additionally anchored silver nanoparticles (AgNPs) was proposed. Ag@Cu-MOF@BG obtained by the spin coating approach in the form of a disc was characterized using PXRD, ATR-FTIR, XPS, ICP-OES, and TEM. Importantly, the material retained its bioactivity, although ion exchange in the bioactive glass administered as a disc is limited. Hydroxyapatite (HA) formation was identified in TEM images after 7 days of immersion of the composite in a physiological-like buffer (pH 7.4, 37 °C). The Cu and Ag contents of Ag@Cu-MOF@BG were as low as 0.013 and 0.018 wt% respectively, but the slow release of the AgNPs ensured its antibacterial nature. Ag@Cu-MOF@BG exhibited antibacterial activity against all tested bacteria (E. coli, S. aureus, P. aeruginosa, and K. pneumoniae) with the diameter of the inhibition zones of their growth between 8 and 10 mm and the reduction index determined to be ≥3. Moreover, the biocompatibility of the new composite has been demonstrated, as shown by cell culture assays with human dermal fibroblasts (HDFs). The results from the migration test also proved that the HDF cell's phenotypic properties were not changed, and the cell adhesion and migration ability were the same as in control indirect assays.

Metal-organic framework-based advanced therapeutic tools for antimicrobial applications

The escalating concern over conventional antibiotic resistance has emphasized the urgency in developing innovative antimicrobial agents. In recent times, metal-organic frameworks (MOFs) have garnered significant attention within the realm of antimicrobial research due to their multifaceted antimicrobial attributes, including the sustained release of intrinsic or exogenous antimicrobial components, chemodynamically catalyzed generation of reactive oxygen species (ROS), and formation of photogenerated ROS. This comprehensive review provides a thorough overview of the synthetic approaches employed in the production of MOF-based materials, elucidating their underlying antimicrobial mechanisms in depth. The focal point lies in elucidating the research advancements across various antimicrobial modalities, encompassing intrinsic component release system, extraneous component release system, auto-catalytical system, and energy conversion system. Additionally, the progress of MOF-based antimicrobial materials in addressing wound infections, osteomyelitis, and periodontitis is meticulously elucidated, culminating in a summary of the challenges and potential opportunities inherent within the realm of antimicrobial applications for MOF-based materials. STATEMENT OF SIGNIFICANCE: Growing concerns about conventional antibiotic resistance emphasized the need for alternative antimicrobial solutions. Metal-organic frameworks (MOFs) have gained significant attention in antimicrobial research due to their diverse attributes like sustained antimicrobial components release, catalytic generation of reactive oxygen species (ROS), and photogenerated ROS. This review covers MOF synthesis and their antimicrobial mechanisms. It explores advancements in intrinsic and extraneous component release, auto-catalysis, and energy conversion systems. The paper also discusses MOF-based materials' progress in addressing wound infections, osteomyelitis, and periodontitis, along with existing challenges and opportunities. Given the lack of related reviews, our findings hold promise for future MOF applications in antibacterial research, making it relevant to your journal's readership.

Studying Fluorescence Sensing of Acetone and Tryptophan and Antibacterial Properties Based on Zinc-Based Triple Interpenetrating Metal-Organic Skeletons

Two triple interpenetrating Zn(II)-based MOFs were studied in this paper. Named [Zn6(1,4-bpeb)4(IPA)6(H2O)]n (MOF-1) and {[Zn3(1,4-bpeb)1.5(DDBA)3]n·2DMF} (MOF-2), {1,4-bpeb = 1,4-bis [2-(4-pyridy1) ethenyl]benze, IPA = Isophthalic acid, DDBA = 3,3'-Azodibenzoic acid}, they were synthesized by the hydrothermal method and were characterized and stability tested. The results showed that MOF-1 had good acid-base stability and solvent stability. Furthermore, MOF-1 had excellent green fluorescence and with different phenomena in different solvents, which was almost completely quenched in acetone. Based on this phenomenon, an acetone sensing test was carried out, where the detection limit of acetone was calculated to be 0.00365% (volume ratio). Excitingly, the MOF-1 could also be used as a proportional fluorescent probe to specifically detect tryptophan, with a calculated detection limit of 34.84 μM. Furthermore, the mechanism was explained through energy transfer and competitive absorption (fluorescence resonance energy transfer (FRET)) and internal filtration effect (IFE). For antibacterial purposes, the minimum inhibitory concentrations of MOF-1 against Escherichia coli and Staphylococcus aureus were 19.52 µg/mL and 39.06 µg/mL, respectively, and the minimum inhibitory concentrations of MOF-2 against Escherichia coli and Staphylococcus aureus were 68.36 µg/mL and 136.72 µg/mL, respectively.