MOFs-Based Materials with Confined Space: Opportunities and Challenges for Energy and Catalytic Conversion

Metal-Organic Frameworks (MOFs) are a very promising material in the fields of energy and catalysis due to their rich active sites, tunable pore size, structural adaptability, and high specific surface area. The concepts of "carbon peak" and "carbon neutrality" have opened up huge development opportunities in the fields of energy storage, energy conversion, and catalysis, and have made significant progress and breakthroughs. In recent years, people have shown great interest in the development of MOFs materials and their applications in the above research fields. This review introduces the design strategies and latest progress of MOFs are included based on their structures such as core-shell, yolk-shell, multi-shelled, sandwich structures, unique crystal surface exposures, and MOF-derived nanomaterials in detail. This work comprehensively and systematically reviews the applications of MOF-based materials in energy and catalysis and reviews the research progress of MOF materials for atmospheric water harvesting, seawater uranium extraction, and triboelectric nanogenerators. Finally, this review looks forward to the challenges and opportunities of controlling the synthesis of MOFs through low-cost, improved conductivity, high-temperature heat resistance, and integration with machine learning. This review provides useful references for promoting the application of MOFs-based materials in the aforementioned fields.

The Promise and Potential of Metal-Organic Frameworks and Covalent Organic Frameworks in Vaccine Nanotechnology

The immune system's complexity and ongoing evolutionary struggle against deleterious pathogens underscore the value of vaccination technologies, which have been bolstering human immunity for over two centuries. Despite noteworthy advancements over these 200 years, three areas remain recalcitrant to improvement owing to the environmental instability of the biomolecules used in vaccines─the challenges of formulating them into controlled release systems, their need for constant refrigeration to avoid loss of efficacy, and the requirement that they be delivered via needle owing to gastrointestinal incompatibility. Nanotechnology, particularly metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), has emerged as a promising avenue for confronting these challenges, presenting a new frontier in vaccine development. Although these materials have been widely explored in the context of drug delivery, imaging, and cancer immunotherapy, their role in immunology and vaccine-related applications is a recent yet rapidly developing field. This review seeks to elucidate the prospective use of MOFs and COFs for biomaterial stabilization, eliminating the necessity for cold chains, enhancing antigen potency as adjuvants, and potentializing needle-free delivery of vaccines. It provides an expansive and critical viewpoint on this rapidly evolving field of research and emphasizes the vital contribution of chemists in driving further advancements.

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.

Preparation of fluorescent sensor based on Zn metal-organic framework for detection and determination of raloxifene as an anticancer drug

Breast cancer is the second leading cause of death for women worldwide. Raloxifene (RLX) is a somewhat effective drug in lowering cholesterol, preventing and treating invasive breast cancer in postmenopausal women with osteoporosis, and does not interfere with breast tissue. Nevertheless, considering the possibility of risk in biological function due to excessive use of anticancer drugs and the adverse effects of drugs in wastewater on plants, animals, and aquatic, it is useful to determine the concentration of RLX in water and human body fluids. Here, a fluorescent metal-organic framework (MOF) nanoparticle based on trinuclear zinc clusters called Zn-MOF was presented, which is a high-performance and fast-response fluorescent chemosensor that can be used to detect RLX based on the fluorescence quenching medium in water. FTIR, XRD, SEM, and EDS analyses were used to identify the functional group and determine the structure and morphology of Zn-MOF. pH range 3-10. The prepared nanoparticles showed symmetric emission with excitation at a wavelength of 310.0 nm. The performance of the proposed fluorescent nanosensor was proportional to the quenching of the fluorescent signal with increasing RLX concentration at 404.0 nm; the quenching fluorescence response was linear in RLX concentration from 0.7 to 350 ng/mL with a significant detection limit equal to 0.485 nM.

Improving the functionality of biodegradable food packaging materials via porous nanomaterials

Non-biodegradability and disposal problems are the major challenges associated with synthetic plastic packaging. This review article discusses a new generation of biodegradable active and smart packaging based on porous nanomaterials (PNMs), which maintains the quality and freshness of food products while meeting biodegradability requirements. PNMs have recently gained significant attention in the field of food packaging due to their large surface area, peculiar structures, functional flexibility, and thermal stability. We present for the first time the recently published literature on the incorporation of various PNMs into renewable materials to develop advanced, environmentally friendly, and high-quality packaging technology. Various emerging packaging technologies are discussed in this review, along with their advantages and disadvantages. Moreover, it provides general information about PNMs, their characterization, and fabrication methods. It also briefly describes the effects of different PNMs on the functionality of biopolymeric films. Furthermore, we examined how smart packaging loaded with PNMs can improve food shelf life and reduce food waste. The results indicate that PNMs play a critical role in improving the antimicrobial, thermal, physicochemical, and mechanical properties of natural packaging materials. These tailor-made materials can simultaneously extend the shelf life of food while reducing plastic usage and food waste.

How Effective are Metal Nanotherapeutic Platforms Against Bacterial Infections? A Comprehensive Review of Literature

The emergence of multidrug-resistant bacteria has been deemed a global crisis that affects humans worldwide. Novel anti-infection strategies are desperately needed because of the limitations of conventional antibiotics. However, the increasing gap between clinical demand and antimicrobial treatment innovation, as well as the membrane permeability obstacle especially in gram-negative bacteria fearfully restrict the reformation of antibacterial strategy. Metal-organic frameworks (MOFs) have the advantages of adjustable apertures, high drug-loading rates, tailorable structures, and superior biocompatibilities, enabling their utilization as drug delivery carriers in biotherapy applications. Additionally, the metal elements in MOFs are usually bactericidal. This article provides a review of the state-of-The-art design, the underlying antibacterial mechanisms and antibacterial applications of MOF- and MOF-based drug-loading materials. In addition, the existing problems and future perspectives of MOF- and MOF-based drug-loading materials are also discussed.

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.

Antibacterial Activity of Two Zn-MOFs Containing a Tricarboxylate Linker

Metal-organic frameworks (MOFs) can be used as reservoirs of metal ions with relevant antibacterial effects. Here, two novel Zn-based MOFs with the formulas [Zn₄(μ₄-O)(μ-FA)L₂] (GR-MOF-8) and [Zn₄(μ₄-O)L₂(H₂O)] (GR-MOF-9) (H₃L: 5-((4-carboxyphenyl)ethynyl) in isophthalic acid and FA (formate anion) were solvothermally synthetized and fully characterized. The antibacterial activity of GR-MOF-8 and 9 was investigated against Staphylococcus aureus (SA) and Escherichia Coli (EC) by the agar diffusion method. Both bacteria are among the most relevant human and animal pathogens, causing a wide variety of infections, and are often related with the development of antimicrobial resistances. While both Zn-based materials exhibited antibacterial activity against both strains, GR-MOF-8 showed the highest inhibitory action, likely due to a more progressive Zn release under the tested experimental conditions. This is particularly evidenced in the inhibition of SA, with an increasing effect of GR-MOF-8 with time, which is of great significance to ensure the disappearance of the microorganism.

MOFs and MOF-Derived Materials for Antibacterial Application

Bacterial infections pose a serious threat to people's health. Efforts are being made to develop antibacterial agents that can inhibit bacterial growth, prevent biofilm formation, and kill bacteria. In recent years, materials based on metal organic frameworks (MOFs) have attracted significant attention for various antibacterial applications due to their high specific surface area, high enzyme-like activity, and continuous release of metal ions. This paper reviews the recent progress of MOFs as antibacterial agents, focusing on preparation methods, fundamental antibacterial mechanisms, and strategies to enhance their antibacterial effects. Finally, several prospects related to MOFs for antibacterial application are proposed, aiming to provide possible research directions in this field.

Metal organic framework-based antibacterial agents and their underlying mechanisms

Bacteria, as the most abundant living organisms, have always been a threat to human life until the development of antibiotics. However, with the wide use of antibiotics over a long time, bacteria have gradually gained tolerance to antibiotics, further aggravating threat to human beings and environmental safety significantly. In recent decades, new bacteria-killing methods based on metal ions, hyperthermia, free radicals, physical pricks, and the coordination of several multi-mechanisms have attracted increasing attention. Consequently, multiple types of new antibacterial agents have been developed. Among them, metal organic frameworks (MOFs) appear to play an increasingly important role. The unique characteristics of MOFs make them suitable multiple-functional platforms. By selecting the appropriate metastable coordination bonds, MOFs can act as reservoirs and release antibacterial metal ions or organic linkers; by constructing a porous structure, MOFs can act as carriers for multiple types of agents and achieve slow and sustained release; and by designing their composition and the pore structure precisely, MOFs can be endowed with properties to produce heat and free radicals under stimulation. Importantly, in combination with other materials, MOFs can act as a platform to kill bacteria effectively through the synergistic effect of multiple types of mechanisms. In this review, we focus on the recent development of MOF-based antibacterial agents, which are classified according to their antibacterial mechanisms.

An Efficient Ultrasound-Assisted Synthesis of Cu/Zn Hybrid MOF Nanostructures With High Microbial Strain Performance

Metal organic frameworks (MOFs) are a promising choice for antibacterial and antifungal activity due to their composition, unique architecture, and larger surface area. Herein, the ultrasonic method was used to synthesize the Cu/Zn-MOF material as an effective hybrid nanostructure with ideal properties. SEM images were used to investigate the product's morphology and particle size distribution. The XRD pattern revealed that the Cu/Zn hybrid MOF nanostructures had a smaller crystalline size distribution than pure Cu and Zn-MOF samples. Furthermore, the BET technique determined that the hybrid MOF nanostructures had a high specific surface area. TG analysis revealed that the hybrid MOF structures were more thermally stable than pure samples. The final product, with remarkable properties, was used as a new option in the field of antibacterial studies. Antibacterial activity was assessed using MIC and MBC against Gram negative and Gram positive strains, as well as antifungal activity using MIC and MFC. The antimicrobial properties of the synthesized Cu/Zn hybrid MOF nanostructures revealed that they were more effective than commercial drugs in some cases. This study's protocol could be a new strategy for introducing new hybrid nanostructures with specific applications.

Recent Research on Hybrid Hydrogels for Infection Treatment and Bone Repair

The repair of infected bone defects (IBDs) is still a great challenge in clinic. A successful treatment for IBDs should simultaneously resolve both infection control and bone defect repair. Hydrogels are water-swollen hydrophilic materials that maintain a distinct three-dimensional structure, helping load various antibacterial drugs and biomolecules. Hybrid hydrogels may potentially possess antibacterial ability and osteogenic activity. This review summarizes the recent progress of different kinds of antibacterial agents (including inorganic, organic, and natural) encapsulated in hydrogels. Several representative hydrogels of each category and their antibacterial mechanism and effect on bone repair are presented. Moreover, the advantages and disadvantages of antibacterial agent hybrid hydrogels are discussed. The challenge and future research directions are further prospected.

Porous Cu-MOF nanostructures with anticancer properties prepared by a controllable ultrasound-assisted reverse micelle synthesis of Cu-MOF

The ultrasonic assisted reverse micelle method (UARM) was used to synthesize Cu-MOF from Cu(NO₃)₂·3H₂O and 2,6-pyridine dicarboxylic acid in a 1:1 molar proportion. It has been characterized using FT-IR, XRD, nitrogen adsorption analysis, SEM and TEM–EDX. The morphology of Cu-MOFs was spherical, with an average particle size distribution of less than 100 nm. Using BET analysis, the surface area of Cu-MOF was found to be 284.94 m²/g. The porous morphology of Cu-MOF was also suggested by SEM and TEM analyses. It has anticancer properties against MCF-7 breast cancer cells. Cytotoxicity testing was performed on MCF-7 breast cancer cells using the MTT cell viability assay, and cell proliferation and viability were found to be approximately 24% higher than the control.

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.

Zn(II) metal-organic architectures from ether-bridged tetracarboxylate linkers: assembly, structural variety and catalytic features

Semi-flexible aromatic polycarboxylic acids are gaining impetus in crystal engineering of functional coordination polymers (CPs). This work opens up the use of two ether-bridged tetracarboxylic acids, 3-(2,5-dicarboxyphenoxy)phthalic acid (H4dpa) and...

Prospects of Exploring the Metal-Organic Framework for Combating Antimicrobial Resistance

Infectious diseases are a major public health concern globally. Infections caused by pathogens with resistance against commonly used antimicrobial drugs or antibiotics (known as antimicrobial resistance, AMR) are becoming extremely difficult to control. AMR has thus been declared as one of the top 10 global public health threats, as it has very limited solutions. The drying pipeline of effective antibiotics has further worsened the situation. There is no absolute treatment, and the limitations of existing methods warrant further development in antimicrobials. Recent developments in the nanomaterial field present them as promising therapeutics and effective alternative to conventional antibiotics and synthetic drugs. The metal-organic framework (MOF) is a recent addition to the antimicrobial category with superior properties. The MOF exerts antimicrobial action on a wide range of species and is highly biocompatible. Additionally, their porous structures allow the incorporation of biomolecules and drugs for synergistic antimicrobial action. This review provides an inclusive summary of the molecular events responsible for resistance development and current trends in antimicrobials to combat antibiotic resistance and explores the potential role of the MOF in tackling the drug-resistant microbial species.

Enhanced Antibacterial Potential of Amoxicillin against Helicobacter pylori Mediated by Lactobionic Acid Coated Zn-MOFs

H. pylori (Helicobacter pylori) causes a common chronic infectious disease and infects around 4.4 billion people worldwide. H. pylori was classified as a member of the primary class of stomach cancer (stomach adenocarcinoma). Hence, this study was conducted to design a novel lactobionic acid (LBA)-coated Zn-MOFs to enhance bactericidal activity of Amoxicillin (AMX) against H. pylori. The synthesized Zn-MOFs were characterized by various techniques which included Dynamic Light Scattering (DLS), Fourier Transform Infrared (FT-IR) Spectroscopy, Powder X-ray diffraction, scanning electron microscope, and atomic force microscope. They were capable of encapsulating an increased amount of AMX and investigated for their efficacy to enhance the antibacterial potential of their loaded drug candidate. Interestingly, it was found that LBA-coated Zn-MOFs significantly reduced the IC₅₀, MIC, and MBIC values of AMX against H. pylori. Morphological investigation of treated bacterial cells further authenticated the above results as LBA-coated Zn-MOFs-treated cells underwent complete distortion compared with non-coated AMX loaded Zn-MOFs. Based on the results of the study, it can be suggested that LBA-coated Zn-MOFs may be an effective alternate candidate to provide new perspective for the treatment of H. pylori infections.

Metal-organic frameworks for diagnosis and therapy of infectious diseases

Infectious diseases are one of the leading cause of mortality and morbidity worldwide. Metal-Organic Frameworks (MOFs), which are porous coordination materials composed of bridging organic ligands and metallic ions or clusters, exhibits great potential to be used against several pathogens, such as bacteria, viruses, fungi and protozoa. MOFs can show sustained release capability, high surface area, adjustable pore size and structural flexibility, which makes them good candidates for new therapeutic systems. This review provides a detailed summary of the biological application of MOFs, focussing on diagnosis and treatment of infectious diseases. MOFs have been reported for usage as antimicrobial agents, drug delivery systems, therapeutic composites, nanozymes and phototherapies. Furthermore, different MOF-based biosensors have also been developed to detect specific pathogens by electrochemical, fluorometric and colorimetric assays. Finally, we present limitations and perspectives in this field.

Broadened bioactivity and enhanced durability of two structurally distinct metal-organic frameworks containing Zn2+ ions and thiabendazole

Novel metal-organic frameworks (MOFs) based on thiabendazole (TBZ) were developed. The two structurally distinct TBZ-MOFs synthesized in this study exhibited enhanced durability and a broader biocidal spectrum than either individual bioactive species (i.e., Zn2+ and TBZ). The characteristics of each TBZ-MOF are related to the coordination modes among the Zn2+ ions and ligand donors. The difference in water solubility between the two TBZ-MOFs due to the structural design allows for the controlled release of the desired bioactive component.

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.

Versatile Nanoscale Metal-Organic Frameworks (nMOFs): An Emerging 3D Nanoplatform for Drug Delivery and Therapeutic Applications

For decades, nanoscale metal-organic frameworks (nMOFs) have attracted extensive interest in biomedicine due to their distinct characteristics, including facile synthesis, porous interior, and tunable biocompatibility. With high porosity, versatile nMOFs allow for the facile encapsulation of various therapeutic agents with exceptionally high payloads. Constructed from metal ions and organic linkers through coordination bonds, nMOFs with plentiful functional groups enable the surface modification for active targeting and enhanced biocompatibility. This review outlines the up-to-date progresses on the exploration of nMOFs in the field of biomedicine. First, the classification and synthesis of nMOFs are discussed, followed by the concrete introduction of drug loading strategies of nMOFs and mechanisms of stimulation-responsive drug release. Second, the smart designs of the nMOFs-based platforms for anticancer and antibacterial treatment are summarized. Finally, the basic challenges faced by nMOFs research and the great potential of biomimetic nMOFs are presented. This review article affords an inspiring insight into the interdisciplinary research of nMOFs and their biomedical applications, which holds great expectation for their further clinical translation.

Metal-Organic Frameworks: Synthetic Methods and Potential Applications

Metal-organic frameworks represent a porous class of materials that are build up from metal ions or oligonuclear metallic complexes and organic ligands. They can be considered as sub-class of coordination polymers and can be extended into one-dimension, two-dimensions, and three-dimensions. Depending on the size of the pores, MOFs are divided into nanoporous, mesoporous, and macroporous items. The latter two are usually amorphous. MOFs display high porosity, a large specific surface area, and high thermal stability due to the presence of coordination bonds. The pores can incorporate neutral molecules, such as solvent molecules, anions, and cations, depending on the overall charge of the MOF, gas molecules, and biomolecules. The structural diversity of the framework and the multifunctionality of the pores render this class of materials as candidates for a plethora of environmental and biomedical applications and also as catalysts, sensors, piezo/ferroelectric, thermoelectric, and magnetic materials. In the present review, the synthetic methods reported in the literature for preparing MOFs and their derived materials, and their potential applications in environment, energy, and biomedicine are discussed.

Chemical targets to deactivate biological and chemical toxins using surfaces and fabrics

The most recent global health and economic crisis caused by the SARS-CoV-2 outbreak has shown us that it is vital to be prepared for the next global threat, be it caused by pollutants, chemical toxins or biohazards. Therefore, we need to develop environments in which infectious diseases and dangerous chemicals cannot be spread or misused so easily. Especially, those who put themselves in situations of most exposure - doctors, nurses and those protecting and caring for the safety of others - should be adequately protected. In this Review, we explore how the development of coatings for surfaces and functionalized fabrics can help to accelerate the inactivation of biological and chemical toxins. We start by looking at recent advancements in the use of metal and metal-oxide-based catalysts for the inactivation of pathogenic threats, with a focus on identifying specific chemical bonds that can be targeted. We then discuss the use of metal-organic frameworks on textiles for the capture and degradation of various chemical warfare agents and their simulants, their long-term efficacy and the challenges they face.

Core–shell ZIF-8@polydopamine nanoparticles obtained by mitigating the polydopamine coating induced self-etching of MOFs: prototypical metal ion reservoirs for sticking to and killing bacteria

ZIF-8@PDA nanoparticles can work as metal ion reservoirs that locally release metal ions to kill bacteria after sticking to them.

Microporous Frameworks as Promising Platforms for Antibacterial Strategies Against Oral Diseases

Nowadays, the heavy burden of oral diseases such as dental caries, periodontitis, endodontic infections, etc., and their consequences on the patients' quality of life indicate a strong need for developing effective therapies. Bacterial infections played an important role in the field of oral diseases, in-depth insight of such oral diseases have given rise to the demand for antibacterial therapeutic strategies. Recently, microporous frameworks have attracted tremendous interest in antibacterial application due to their well-defined porous structures for drug delivery. In addition, intensive efforts have been made to enhance the antibacterial performance of microporous frameworks, such as ion doping, photosensitizer incorporation as building blocks, and surface modifications. This review article aims on the major recent developments of microporous frameworks for antibacterial applications against oral diseases. The first part of this paper puts concentration on the cutting-edge researches on the versatile antibacterial strategies of microporous materials via drug delivery, inherent activity, and structural modification. The second part discusses the antibacterial applications of microporous frameworks against oral diseases. The applications of microporous frameworks not only have promising therapeutic potential to inhibit bacterial plaque-initiated oral infectious diseases, but also have a wide applicability to other biomedical applications.

Novel Metal-Organic Framework-Based Photocrosslinked Hydrogel System for Efficient Antibacterial Applications

Metal-organic frameworks (MOFs) can be applied in biology and medicine as drug delivery systems by carrying drugs on their surfaces or releasing bioactive ligands. To investigate the therapeutic potential of hydrogels that contain MOFs, three MOFs containing glutarate and 1,2-bis(4-pyridyl)ethylene ligands were synthesized by the previously reported hydrothermal or solvothermal reactions: Cu-MOF 1, Co-MOF 2, and Zn-MOF 3. Bioactive MOF-embedded hydrogels (hydrogel@Cu-MOF 1, hydrogel@Co-MOF 2, and hydrogel@Zn-MOF 3) were prepared by UV light-mediated thiol-ene photopolymerization using diacrylated polyethylene glycol (PEG), 4-arm-thiolated PEG, and MOFs. The activities of the MOF-embedded hydrogels were tested against the Gram-negative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus. These MOF-embedded hydrogels were observed to be very stable, based on the release test of M^II ions, and both hydrogel@Cu-MOF 1 and hydrogel@Co-MOF 2 showed excellent antibacterial activity. Although, in human dermal fibroblasts, hydrogel@Cu-MOF 1 showed no cytotoxic effects, it exhibited 99.9% antibacterial effects at the minimum bactericidal concentration. Physical properties such as the surface area and dimension of MOFs with different central metals appeared to be more important than the chemical properties of the ligands in determining the effects on bacteria. These MOF-embedded hydrogels may be useful in antibacterial applications such as cosmetics, treatment of skin diseases, and drug delivery owing to their low cytotoxicity and high bactericidal activity.

Antibacterial applications of metal-organic frameworks and their composites

Metal-organic frameworks (MOFs) are porous coordination materials composed of multidentate organic ligands and metal ions or metal clusters. MOFs have the great potential to be utilized in antibacterial materials for biological, environmental, and food antimicrobial fields. In recent years, MOFs have been applied to various antibacterial fields due to their sustained release capability, porosity, and structural flexibility in combination with many chemicals and/or materials (such as nanoparticles, antibiotics, phytochemicals, and polymers). This review offers a detailed summary of the antibacterial applications of MOFs and their composites, focusing on the combination types of MOFs composites and the antibacterial effect in different applications. These applications are illustrated by the examples discussed in this review.

Metal–organic framework based antibiotic release and antimicrobial response: an overview

MOF and MOF based heterostructures for antibacterial applications.

A novel synthesis of new antibacterial nanostructures based on Zn-MOF compound: design, characterization and a high performance application

In this study, the novel zinc metal-organic frameworks (MOF) nanostructure has been employed, which was developed using an affordable, environmental friendly, efficient and fast method of ultrasound-assisted reverse micelle (UARM). These nanostructures were identified with various techniques such as FT-IR, XRD, BET, SEM, TG-DSC, TEM and EDS. It was found that the Zn-MOF samples have favorable physicochemical properties. The impact of experimental parameters of the UARM method is effective on the resulting properties, such as high surface area of the products that increases the interactions between the Zn-MOF nanostructure and bacteria.Their antibacterial activities were investigated using diffusion methods in agar and also with dilutions of Zn-MOF samples. Antibiotics (tetracycline and ampicillin) and their anti-biofilm effects were evaluated using microplate method. Obtained results revealed that the Zn-MOF nanostructures have high antibacterial properties which, could be due to the nature of the applied Zn-MOF as well as the optimization process. The Zn- MOF nanostructures could be a novel antibacterial material as biocatalyst processes.

Exploring the Coordination Effect of GO@MOF-5 as Catalyst on Thermal Decomposition of Ammonium Perchlorate

Prepared composite materials based on [Zn₄O(benzene-1,4-dicarboxylate)₃] (MOF-5) and graphene oxide (GO) via a simple green solvothermal method, at which GO was used as platform to load MOF-5, and applied to the thermal decomposition of AP. The obtained composites were characterized by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared (FT-IR), differential scanning calorimetry and thermalgravimetric (DSC-TG). The analyses confirmed that the composite material (GO@) MOF-5 can not only improve the decomposition peak temperature of AP from the initial 409.7 ^°C to 321.9 ^°C, but also can improve the enthalpy (△H) from 576 J g^-1 to 1011 J g^-1 and reduce the activation energy (E_a), thereby accelerating the decomposition reaction. The high-specific surface area of the MOF material can provide a large number of active sites, so that the transition metal ions supported thereon can participate more effectively in the electron transfer process, and GO plays its role as a bridge by its efficient thermal and electrical conductivity. Together, accelerate the thermal decomposition process of AP.

Zinc-based metal-organic frameworks as nontoxic and biodegradable platforms for biomedical applications: review study

Development of biomedical systems for controllable drug delivery systems and construction of biosensors is imperative to reduce side effects of common treatment techniques and enhance the therapeutic efficacy. To address this issue, metal-organic frameworks (MOFs) as hybrid porous polymeric structures have attracted worldwide attention due to their unprecedented opportunities in vast range of applications in diverse fields including chemistry, biological, and medicinal science as gas storage/separation, sensing, and drug delivery systems. Recently, biomedical application has become an interesting and promising issue for development and usage of multi-functional MOFs. Flexible chemical composition and versatile porous structure of MOFs enable the engineering and enhancement of their medical formulation and functionality as practical carriers for whether therapeutic or imaging agents. One important point in this domain is the efficient delivery of drugs in the body using nontoxic and biodegradable carriers. This review brings together the literatures that addressing the biomedical applications of Zinc-based MOFs (i.e. as drug delivery systems or nontoxic agent in matter of therapeutic applications) to present recent achievements in this interesting field.

Antibacterial activities of Cu-MOFs containing glutarates and bipyridyl ligands

Metal-organic frameworks (MOFs) can be utilized as antibacterial agents due to their effective antibacterial activities. Four three-dimensional (3D) Cu-MOFs formulated as [Cu₂(Glu)₂(μ-L)]·x(H₂O) (Glu is glutarate, and L is bpy = 4,4'-bipyridine (1), bpa = 1,2-bis(4-pyridyl)ethane (2), bpe = 1,2-bis(4-pyridyl)ethylene (3), and bpp = 1,2-bis(4-pyridyl)propane (4)) were synthesized by hydrothermal reactions or modified literature methods. Their solid-state structures were slightly modified to increase their hydrolytic stabilities in aqueous solution. Despite the seemingly sufficient void spaces in all the solvent-free MOFs, only the thermally activated form of MOF 2 displayed selective gas uptake ability for CO₂ over N₂ and H₂. The antibacterial activities of the four Cu-MOFs, 1, 2, 3, and 4, were investigated by determining their minimal bactericidal concentration (MBC) values against five strains of bacteria, including E. coli, S. aureus, K. pneumonia, P. aeruginosa, and MRSA, which can be easily met in our daily surrounding environments. Although these Cu-MOFs were found to be structurally very stable in aqueous medium during antibacterial activity tests, they exhibited excellent antibacterial activities against all five kinds of bacteria, including Gram-positive bacteria (S. aureus and MRSA) and Gram-negative bacteria (E. coli, K. pneumonia, and P. aeruginosa), with very low MBCs. The robust 3D frameworks with surface active metal sites rather than the small amount of leached Cu^II ions may participate more strongly in inactivating various kinds of bacteria and reduce potential cytotoxicity mainly caused by leached metal ions.