Functionalization of MOF-5 with mono-substituents: effects on drug delivery behavior

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.

Enhancing visible-light-driven photocatalysis: unveiling the remarkable potential of H2O2-assisted MOF/COF hybrid material for organic pollutant degradation

In this study, we synthesized MOF/COF hybrid material (NH2-MOF-5/MCOF) by integrating NH2-MOF-5 (Zn) with a melamine-based COF (MCOF) to target the photocatalytic degradation of methylene blue (MB) dye. Characterization using SEM, XRD, XPS, FT-IR, and UV-DRS confirmed the synthesized MOF/COF hybrid's exceptional photocatalytic performance under visible light. The addition of H2O2 significantly enhanced the photocatalytic degradation, achieving removal rates of 90%, 92%, and 57% for 11.75 mg L-1, 30 mg L-1, and 83 mg L-1 of MB, respectively. Kinetic studies revealed first-order kinetics, with a rate constant nearly 3.5 times higher with added H2O2. We proposed a comprehensive photocatalytic mechanism elucidated through energy band structure analysis and scavenger tests. Our findings revealed the formation of a heterojunction between NH2-MOF-5 and MCOF, which mitigates electron-hole recombination, with ∙OH identified as the principal species governing methylene blue degradation. Moreover, the NH2-MOF-5/MCOF hybrid displayed excellent reusability and chemical stability over six cycles. Notably, this H2O2-assisted hybrid material demonstrated the removal of 99% of ibuprofen, a pharmaceutical drug, showcasing its broad applicability in removing organic contaminants in aqueous solutions, thereby holding great promise for wastewater treatment.

Microwave-Responsive Metal-Organic Frameworks (MOFs) for Enhanced In Vitro Controlled Release of Doxorubicin

Metal-organic frameworks (MOFs) are excellent candidates for a range of applications because of their numerous advantages, such as high surface area, porosity, and thermal and chemical stability. In this study, microwave (MW) irradiation is used as a novel stimulus in vitro controlled release of Doxorubicin (DOX) from two MOFs, namely Fe-BTC and MIL-53(Al), to enhance drug delivery in cancer therapy. DOX was encapsulated into Fe-BTC and MIL-53(Al) with drug-loading efficiencies of up to 67% for Fe-BTC and 40% for MIL-53(Al). Several characterization tests, including XRD, FTIR, TGA, BET, FE-SEM, and EDX, confirmed both MOF samples' drug-loading and -release mechanisms. Fe-BTC exhibited a substantial improvement in drug-release efficiency (54%) when exposed to microwave irradiation at pH 7.4 for 50 min, whereas 11% was achieved without the external modality. A similar result was observed at pH 5.3; however, in both cases, the release efficiencies were substantially higher with microwave exposure (40%) than without (6%). In contrast, MIL-53(Al) exhibited greater sensitivity to pH, displaying a higher release rate (66%) after 38 min at pH 5.3 compared to 55% after 50 min at pH 7.4 when subjected to microwave irradiation. These results highlight the potential of both MOFs as highly heat-responsive to thermal stimuli. The results of the MTT assay demonstrated the cell viability across different concentrations of the MOFs after two days of incubation. This suggests that MOFs hold promise as potential candidates for tumor targeting. Additionally, the fact that the cells maintained their viability at different durations of microwave exposure confirms that the latter is a safe modality for triggering drug release from MOFs.

MOFs for next-generation cancer therapeutics through a biophysical approach-a review

Metal-organic frameworks (MOFs) have emerged as promising nanocarriers for cancer treatment due to their unique properties. Featuring high porosity, extensive surface area, chemical stability, and good biocompatibility, MOFs are ideal for efficient drug delivery, targeted therapy, and controlled release. They can be designed to target specific cellular organelles to disrupt metabolic processes in cancer cells. Additionally, functionalization with enzymes mimics their catalytic activity, enhancing photodynamic therapy and overcoming apoptosis resistance in cancer cells. The controllable and regular structure of MOFs, along with their tumor microenvironment responsiveness, make them promising nanocarriers for anticancer drugs. These carriers can effectively deliver a wide range of drugs with improved bioavailability, controlled release rate, and targeted delivery efficiency compared to alternatives. In this article, we review both experimental and computational studies focusing on the interaction between MOFs and drug, explicating the release mechanisms and stability in physiological conditions. Notably, we explore the relationship between MOF structure and its ability to damage cancer cells, elucidating why MOFs are excellent candidates for bio-applicability. By understanding the problem and exploring potential solutions, this review provides insights into the future directions for harnessing the full potential of MOFs, ultimately leading to improved therapeutic outcomes in cancer treatment.

Sub-acute administration of metal-organic Framework-5 induces behavioral impairments and augments the levels of oxidative stress and inflammation in the brain of rats

Metal-organic frameworks (MOFs) are known as potential pharmaceutical carriers because of their structure. Here, we evaluated the sub-acute administrations of MOF-5 on behavioral parameters, oxidative stress, and inflammation levels in rats. Thirty-two male Wistar rats received four injections of saline or MOF-5 at different doses which were 1, 10, and 50 mg/kg via caudal vein. Y-Maze and Morris-Water Maze (MWM) tests were used to explore working memory and spatial learning and memory, respectively. The antioxidant capacity and oxidative stress level of brain samples were assessed by ferric reducing antioxidant power (FRAP) and thiobarbituric acid-reacting substance (TBARS) assay, respectively. The expression levels of GFAP, IL-1β, and TNF-α were also measured by quantitative real-time reverse-transcription PCR (qRT-PCR). Sub-acute administration of MOF-5 reduced the spatial learning and memory as well as working memory, dose-dependently. The levels of FRAP were significantly reduced in rats treated with MOF-5 at higher doses. The Malondialdehyde (MDA) levels increased at the dose of 50 mg/kg. Additionally, the expression levels of IL-1β and TNF-α were significantly elevated in the rats' brains that were treated with MOF-5. Our findings indicate that sub-acute administration of MOF-5 induces cognitive impairment dose-dependently which might be partly mediated by increasing oxidative stress and inflammation.

Smartphone-Assisted EY@MOF-5-Based Dual-Emission Fluorescent Sensor for Rapid On-Site Detection of Daclatasvir and Nitenpyram

Fluorescent metal-organic frameworks (MOFs) are promising sensing materials with tunable and robust structural properties and remarkable luminescent capabilities. In this study, a novel dual-emission fluorescent metal-organic framework (EY@MOF-5) composite is synthesized by a one-pot bottle-around-ship approach. Eosin Y (EY) is encapsulated in MOF-5 to enhance its fluorescence properties and selectivity, effectively addressing typical MOF-5 limitations. EY@MOF-5 serves as a versatile dual-functional fluorescent sensor for two different analytes, daclatasvir (DCT) and nitenpyram (NTP), showing an impressive linear range of 10-200 nM and 0.1-300 μM, with detection limits of 233 pM and 65 nM, respectively. The established method is ultrafast, highly sensitive, and extremely selective for DCT and NTP detection in complex biological and food samples. Fluorescence results are compared and validated with the recommended UPLC method. Then, a smartphone-integrated sensing system is introduced for on-site, real-time, and quantitative analysis of DCT and NTP. The smartphone-assisted intelligent sensing method manifests promising results for DCT and NTP monitoring in biological and food samples, demonstrating its promising potential for the on-site detection of biologically and environmentally significant analytes.

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.

Storage and Diffusion of Carbon Dioxide in the Metal Organic Framework MOF-5─A Semi-empirical Molecular Dynamics Study

Metal-organic frameworks (MOFs) have attracted increasing attention due to their high porosity for exceptional gas storage applications. MOF-5 belongs to the family of isoreticular MOFs (IRMOFs) and consists of Zn4O6+ clusters linked by 1,4-benzenedicarboxylate. Due to the large number of atoms in the unit cell, molecular dynamics simulation based on density functional theory has proved to be too demanding, while force field models are often inadequate to model complex host-guest interactions. To overcome this limitation, an alternative semi-empirical approach using a set of approximations and extensive parametrization of interactions called density functional tight binding (DFTB) was applied in this work to study CO2 in the MOF-5 host. Calculations of pristine MOF-5 yield very good agreement with experimental data in terms of X-ray diffraction patterns as well as mechanical properties, such as the negative thermal expansion coefficient and the bulk modulus. In addition, different loadings of CO2 were introduced, and the associated self-diffusion coefficients and activation energies were investigated. The results show very good agreement with those of other experimental and theoretical investigations. This study provides detailed insights into the capability of semi-empirical DFTB-based molecular dynamics simulations of these challenging guest@host systems. Based on the comparison of the guest-guest pair distributions observed inside the MOF host and the corresponding gas-phase reference, a liquid-like structure of CO2 can be deduced upon storage in the host material.

Performance of Zr-Based Metal-Organic Framework Materials as In Vitro Systems for the Oral Delivery of Captopril and Ibuprofen

Zr-based metal-organic framework materials (Zr-MOFs) with increased specific surface area and pore volume were obtained using chemical (two materials, Zr-MOF1 and Zr-MOF3) and solvothermal (Zr-MOF2) synthesis methods and investigated via FT-IR spectroscopy, TGA, SANS, PXRD, and SEM methods. The difference between Zr-MOF1 and Zr-MOF3 lies in the addition of reactants during synthesis. Nitrogen porosimetry data indicated the presence of pores with average dimensions of ~4 nm; using SANS, the average size of the Zr-MOF nanocrystals was suggested to be approximately 30 nm. The patterns obtained through PXRD were characterized by similar features that point to well-crystallized phases specific for the UIO-66 type materials; SEM also revealed that the materials were composed of small and agglomerate crystals. Thermogravimetric analysis revealed that both materials had approximately two linker deficiencies per Zr6 formula unit. Captopril and ibuprofen loading and release experiments in different buffered solutions were performed using the obtained Zr-based metal-organic frameworks as drug carriers envisaged for controlled drug release. The carriers demonstrated enhanced drug-loading capacity and showed relatively good results in drug delivery. The cumulative percentage of drug release in phosphate-buffered solution at pH 7.4 was higher than that in buffered solution at pH 1.2. The release rate could be controlled by changing the pH of the releasing solution. Different captopril release behaviors were observed when the experiments were performed using a permeable dialysis membrane.

Novel UiO-NH2-like Zr-Based MOF (Basu-DPU) as an Excellent Catalyst for Preparation of New 6H-Chromeno[4,3-b]quinolin-6-ones

A new two-fold interpenetrated pillar-layered metal-organic framework (MOF) was designed and synthesized based on zirconium cations, an amine-functionalized ligand, and a linear exo-bidentate bis-pyridine ligand. The structure of the prepared framework was evaluated using various techniques, such as Fourier transform infrared (FTIR), ¹³C NMR, energy-dispersive X-ray (EDX), elemental mapping analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TGA/DTA), and Brunauer-Emmett-Teller (BET). Then, catalytic application of the prepared zirconium-based MOF was successfully explored in the synthesis of novel 6H-chromeno[4,3-b]quinolin-6-ones 4(a-l) through a one-pot three-component condensation reaction of 4-hydroxycumarine, 1-naphthylamine, and aromatic aldehydes under solvent-free conditions at 110 °C. The pure products were obtained with high atom efficiency (AE) and short reaction times and characterized by FTIR, NMR, and mass spectrometry techniques.

Enhanced lysosomal escape of cell penetrating peptide-functionalized metal-organic frameworks for co-delivery of survivin siRNA and oridonin

In recent years, small interfering RNA (siRNA) has been widely used in the treatment of human diseases, especially tumors, and has shown great appeal. However, the clinical application of siRNA faces several challenges. Insufficient efficacy, poor bioavailability, poor stability, and lack of responsiveness to a single therapy are the main problems affecting tumor therapy. Here, we designed a cell-penetrating peptide (CPP)-modified metal organic framework nanoplatform (named PEG-CPP33@ORI@survivin siRNA@ZIF-90, PEG-CPP33@NPs) for targeted co-delivery of oridonin (ORI), a natural anti-tumor active ingredient) and survivin siRNA in vivo. This can improve the stability and bioavailability of siRNA and the efficacy of siRNA monotherapy. The high drug-loading capacity and pH-sensitive properties of zeolite imidazolides endowed the PEG-CPP33@NPs with lysosomal escape abilities. The Polyethylene glycol (PEG)-conjugated CPP (PEG-CPP33) coating significantly improved the uptake in the PEG-CPP33@NPs in vitro and in vivo. The results showed that the co-delivery of ORI and survivin siRNA greatly enhanced the anti-tumor effect of PEG-CPP33@NPs, demonstrating the synergistic effect between ORI and survivin siRNA. In summary, the novel targeted nanobiological platform loaded with ORI and survivin siRNA presented herein showed great advantages in cancer therapy, and provides an attractive strategy for the synergistic application of chemotherapy and gene therapy.

Recent advances in Metal-Organic Frameworks as nanocarriers for triggered release of anticancer drugs: Brief history, biomedical applications, challenges and future perspective

Metal-Organic Frameworks (MOFs) have emerged as a promising biomedical material due to its unique features such as high surface area, pore volume, variable pore size, flexible functional groups, and excellent efficiency for drug loading. In this review, we explored the use of novel and smart metal organic frameworks as drug delivery vehicles to discover a safer and more controlled mode of drug release aiming to minimize their side effects. Here, we systematically discussed the background of MOFs following a thorough review on structural and physical properties of MOFs, their synthesis techniques, and the important characteristics to establish a strong foundation for future research. Furthermore, the current status on the potential applications of MOF-based stimuli-responsive drug delivery systems, including pH-, ion-, temperature-, light-, and multiple responsive systems for the delivery of anticancer drugs has also been presented. Lastly, we discuss the prospects and challenges in implementation of MOF-based materials in the drug delivery. Therefore, this review will help researchers working in the relevant fields to enhance their understanding of MOFs for encapsulation of various drugs as well as their stimuli responsive mechanism.

Current perspectives and trend of nanomedicine in cancer: A review and bibliometric analysis

The limitations of traditional cancer treatments are driving the creation and development of new nanomedicines. At present, with the rapid increase of research on nanomedicine in the field of cancer, there is a lack of intuitive analysis of the development trend, main authors and research hotspots of nanomedicine in the field of cancer, as well as detailed elaboration of possible research hotspots. In this review, data collected from the Web of Science Core Collection database between January 1st, 2000, and December 31st, 2021, were subjected to a bibliometric analysis. The co-authorship, co-citation, and co-occurrence of countries, institutions, authors, literature, and keywords in this subject were examined using VOSviewer, Citespace, and a well-known online bibliometrics platform. We collected 19,654 published papers, China produced the most publications (36.654%, 7204), followed by the United States (29.594%, 5777), and India (7.780%, 1529). An interesting fact is that, despite China having more publications than the United States, the United States still dominates this field, having the highest H-index and the most citations. Acs Nano, Nano Letters, and Biomaterials are the top three academic publications that publish articles on nanomedicine for cancer out of a total of 7580 academic journals. The most significant increases were shown for the keywords "cancer nanomedicine", "tumor microenvironment", "nanoparticles", "prodrug", "targeted nanomedicine", "combination", and "cancer immunotherapy" indicating the promising area of research. Meanwhile, the development prospects and challenges of nanomedicine in cancer are also discussed and provided some solutions to the major obstacles.

Negatively Charged MOF-Based Composite Anion Exchange Membrane with High Cation Selectivity and Permeability

Every metal and metallurgical industry is associated with the generation of wastewater, influencing the living and non-living environment, which is alarming to environmentalists. The strict regulations about the dismissal of acid and metal into the environment and the increasing emphasis on the recycling/reuse of these effluents after proper remedy have focused the research community's curiosity in developing distinctive approaches for the recovery of acid and metals from industrial wastewaters. This study reports the synthesis of UiO-66-(COOH)₂ using dual ligand in water as a green solvent. Then, the prepared MOF nanoparticles were introduced into the DMAM quaternized QPPO matrix through a straightforward blending approach. Four defect-free UiO-66-(COOH)₂/QPPO MMMs were prepared with four different MOF structures. The BET characterization of UiO-66-(COOH)₂ nanoparticles with a highly crystalline structure and sub-nanometer pore size (~7 Å) was confirmed by XRD. Because of the introduction of MOF nanoparticles with an electrostatic interaction and pore size screening effect, a separation coefficient (S_HCl/FeCl2) of 565 and U_HCl of 0.0089 m·h^-1 for U-C(60)/QPPO were perceived when the loading dosage of the MOF content was 10 wt%. The obtained results showed that the prepared defect-free MOF membrane has broad prospects in acid recovery applications.

Three-fold interpenetrated metal–organic framework as a multifunctional fluorescent probe for detecting 2,4,6-trinitrophenol, levofloxacin, and l-cystine

A robust Zn(ii) MOF with good chemical and thermal stability, was prepared as an effective fluorescent probe for 2,4,6-trinitrophenol (TNP), levofloxacin (LVX) and l-cystine (l-Cys) with recyclability.

Recent advances in molecular logic gate chemosensors based on luminescent metal organic frameworks

Luminescent metal-organic frameworks (LMOFs) as chemosensors, can sense various analytes, such as heavy metal ions, antibiotics, pesticides, and small biological molecules. Based on the fluorescence characteristics of LMOFs, a variety of logic gates have been developed. In this review, we mainly discuss some common logic systems based on LMOFs, and then summarize the strategies of constructing logic gates from two perspectives. One is based on superior characteristics of MOFs, which can be synthesized from Ln3+ based MOFs (Ln-MOFs) or form hybrids by encapsulating different materials, including metal ions, dyes, and quantum dots (QDs). The other is to control the presence of inputs by reactions between different reactants and then further control switches of logic gates. Additionally, the common sensing mechanisms of LMOFs in logic gates are discussed. In the end, we have envisioned MOFs that possess a promising future in logic computing areas.

Natural Polymers Decorated MOF-MXene Nanocarriers for Co-delivery of Doxorubicin/pCRISPR

A one-pot and facile method with assistance of high gravity was applied for the synthesis of inorganic two-dimensional MOF-5 embedded MXene nanostructures. The innovative inorganic MXene/MOF-5 nanostructure was applied in co-delivery of drug and gene, and to increase its bioavailability and interaction with the pCRISPR, the nanomaterial was coated with alginate and chitosan. The polymer-coated nanosystems were fully characterized, and the sustained DOX delivery and comprehensive cytotoxicity studies were conducted on the HEK-293, PC12, HepG2, and HeLa cell lines, demonstrating acceptable and excellent cell viability at both very low (0.1 μg.mL^-1) and high (10 μg·mL^-1) concentrations. The chitosan-coated nanocarriers showed superior relative cell viability compared to others, more than 60% on average of relative cell viability in all of the cell lines. Then, alginate-coated nanocarriers ranked at second place on the higher relative cell viability, more than 50% on average for all of the cell lines. Also, MTT results showed a complete dose-dependence, and by increasing the time of treatment from 24 to 72 h, the relative cell viability decreased by a meaningful slope; however, this decrease was optimized by coating the nanocarrier with chitosan and alginate. The nanosystems were also tagged with pCRISPR to analyze the potential application in the co-delivery of drug/gene. CLSM images of the HEK-293 and HeLa cell lines unveiled successful delivery of pCRISPR into the cells, and the enhanced green fluorescent protein (EGFP) reached up to ca. 26% for the HeLa cell line. Also, a considerable drug payload of 35.7% was achieved, which would be because of the interactions between the nanocarrier and the doxorubicin. In this unprecedented report pertaining to the synthesis of MXene assisted by a MOF and high-gravity technique, the methodology and the optimized ensuing MXene/MOF-5 nanosystems can be further developed for the co-delivery of drug/gene in animal models.

Stimuli -triggered fluoro-switching in metal-organic frameworks: applications and outlook

The design and synthesis of efficient sensor materials with fast-responsive and ultrasensitive detection ability is critical to monitor ecological safety, supervise human health, control industrial wastes, and govern food quality among others. Metal-organic frameworks (MOFs) or coordination polymers (CPs) are a new class of porous crystalline materials that have emerged in several potential applications in last two decades. In particular, applications of MOFs as sensory scaffolds for the detection of hazardous pollutants have attracted researchers due to their fabulous structural characteristics and wide range of pore environment tunability. Among several transducer procedures, the luminescence detection of a particular analyte is immensely desirable as it is easy to handle and cost effective, where visual changes in physicochemical attributes can be comprehended via a quick naked eye detection. The porous nature of MOFs facilitates the pre-concentration of target analytes within the pore structure and provides superior host-guest interaction with good detection limits when compared to conventional materials. To this end, guest-induced fluorescence switching in sensory MOFs with good recyclability and unique detectable fingerprints are of particular importance to benefit futuristic monitoring aptitudes and promises environmental remediation. In this review, we present the latest literature based on the analyte-responsive modulation of fluorescence intensity in MOFs towards the detection of target pollutants and discuss the underlying sensing mechanism, which can assist in developing new useful nano-scale devices and sensors.