Construction of Fe-doped ZIF-8/DOX nanocomposites for ferroptosis strategy in the treatment of breast cancer

In situ generation of copper(Ⅱ)/diethyldithiocarbamate complex through tannic acid/copper(Ⅱ) network coated hollow mesoporous silica for enhanced cancer chemodynamic therapy

The Cu2+ complex formed by the coordination of disulfiram (DSF) metabolite diethyldithiocarbamate (DTC), Cu(DTC)2, can effectively inhibit tumor growth. However, insufficient Cu2+ levels in the tumor microenvironment can impact tumor-suppressive effects of DTC. In this study, we proposed a Cu2+ and DSF tumor microenvironment-targeted delivery system. This system utilizes hollow mesoporous silica (HMSN) as a carrier, after loading with DSF, encases it using a complex of tannic acid (TA) and Cu2+ on the outer layer. In the slightly acidic tumor microenvironment, TA/Cu undergoes hydrolysis, releasing Cu2+ and DSF, which further form Cu(DTC)2 to inhibit tumor growth. Additionally, Cu2+ can engage in a Fenton-like reaction with H2O2 in the tumor microenvironment to form OH, therefore, chemodynamic therapy (CDT) and Cu(DTC)2 are used in combination for tumor therapy. In vivo tumor treatment results demonstrated that AHD@TA/Cu could accumulate at the tumor site, achieving a tumor inhibition rate of up to 77.6 %. This study offers a novel approach, circumventing the use of traditional chemotherapy drugs, and provides valuable insights into the development of in situ tumor drug therapies.

Chitosan/NH2-MIL-125 (Ti) scaffold loaded with doxorubicin for postoperative bone tumor clearance and osteogenesis: An in vitro study

Surgical resection remains the primary treatment modality for bone tumors. However, it is prone to local bone defects and tumor recurrence. Therefore, there is an urgent need for multifunctional biomaterials that combine tumor treatment and bone repair after bone tumor surgery. Herein, a chitosan composite scaffold (CS/DOX@Ti-MOF) was designed for both tumor therapy and bone repair. Among them, the amino-functionalized Ti-based metal-organic framework (NH2-MIL-125 (Ti), Ti-MOF) has a high specific surface area of 1116 m2/g and excellent biocompatibility, and promotes osteogenic differentiation. The doxorubicin (DOX) loading capacity of Ti-MOF was 322 ± 21 mg/g, and DOX@Ti-MOF has perfect antitumor activity. Furthermore, the incorporation of DOX@Ti-MOF improved the physical and mechanical properties of the composite scaffolds, making the scaffold surface rough and favorable for cells to attach. CS/DOX@Ti-MOF retains the unique properties of each component. It responds to the release of DOX in the tumor microenvironment to remove residual tumor cells, followed by providing a site for cell attachment, proliferation, and differentiation. This promotes bone repair and achieves the sequential treatment of postoperative bone tumors. Overall, CS/DOX@Ti-MOF may be a promising substitute for postoperative bone tumor clearance and bone defect repair. It also provides a possible strategy for postoperative bone tumor treatment.

Nanocatalytic theranostics with intracellular mutual promotion for ferroptosis and chemo-photothermal therapy

The reactive oxygen species (ROS) produced through the Fenton reaction, induces lipid peroxide (LPO), causing cellular structural damage and ultimately triggering ferroptosis. However, the generation of ROS in the tumor microenvironment (TME) is limited by the catalytic efficiency of the Fenton reaction. Herein, a novel hollow mesoporous silica nanoparticle (HMSN) combined with multi-metal sulfide-doped mesoporous silica nanocatalyzers (NCs) was developed, namely MxSy-HMSN NCs (M represents Cu Mn and Fe, S denotes sulfur). The MxSy-HMSN can dramatically enhanced the ferroptosis by: (1) facilitating the conversion of H2O2 to ·OH through Fenton or Fenton-like reactions through co-catalysis; (2) weakening ROS scavenging systems by depleting the over expressed glutathione (GSH) in TME; (3) providing exceptional photothermal therapy to augment ferroptosis. The MxSy-HMSN can also act as smart cargos for anticancer drug-doxorubicin (DOX). The release of DOX is responsive to GSH/pH/Near-infrared Light (NIR) irradiation at the tumor lesion, significantly improving therapeutic outcomes while minimizing side effects. Additionally, the MxSy-HMSN has demonstrated excellent magnetic resonance imaging (MRI) potential. This smart MxSy-HMSN offer a synergetic approach combining ferroptosis with chemo-photothermal therapy and magnetic resonance imaging (MRI) diagnose, which could be an informative guideline for the design of future NCs.

Biomedical application of metal-organic frameworks (MOFs) in cancer therapy: Stimuli-responsive and biomimetic nanocomposites in targeted delivery, phototherapy and diagnosis

The nanotechnology is an interdisciplinary field that has become a hot topic in cancer therapy. Metal-organic frameworks (MOFs) are porous materials and hybrid composites consisted of organic linkers and metal cations. Despite the wide application of MOFs in other fields, the potential of MOFs for purpose of cancer therapy has been revealed by the recent studies. High surface area and porosity, significant drug loading and encapsulation efficiency are among the benefits of using MOFs in drug delivery. MOFs can deliver genes/drugs with selective targeting of tumor cells that can be achieved through functionalization with ligands. The photosensitizers and photo-responsive nanostructures including carbon dots and gold nanoparticles can be loaded in/on MOFs to cause phototherapy-mediated tumor ablation. The immunogenic cell death induction and increased infiltration of cytotoxic CD8+ and CD4+ T cells can be accelerated by MOF platforms in providing immunotherapy of tumor cells. The stimuli-responsive MOF platforms responsive to pH, redox, enzyme and ion can accelerate release of therapeutics in tumor site. Moreover, MOF nanocomposites can be modified ligands and green polymers to improve their selectivity and biocompatibility for cancer therapy. The application of MOFs for the detection of cancer-related biomarkers can participate in the early diagnosis of patients.

Role of Metal-Organic Frameworks (MOFs) in treating and diagnosing microbial infections

This review article highlights the innovative role of metal-organic frameworks (MOFs) in addressing global healthcare challenges related to microbial infections. MOFs, comprised of metal nodes and organic ligands, offer unique properties that can be applied in the treatment and diagnosis of these infections. Traditional methods, such as antibiotics and conventional diagnostics, face issues such as antibiotic resistance and diagnostic limitations. MOFs, with their highly porous and customizable structure, can encapsulate and deliver therapeutic or diagnostic molecules precisely. Their large surface area and customizable pore structures allow for sensitive detection and selective recognition of microbial pathogens. They also show potential in delivering therapeutic agents to infection sites, enabling controlled release and possible synergistic effects. However, challenges like optimizing synthesis techniques, enhancing stability, and developing targeted delivery systems remain. Regulatory and safety considerations for clinical translation also need to be addressed. This review not only explores the potential of MOFs in treating and diagnosing microbial infections but also emphasizes their unique approach and discusses existing challenges and future directions.

Hybrid organic frameworks: Synthesis strategies and applications in photocatalytic wastewater treatment - A review

Hybrid organic framework materials are a class of hierarchical porous crystalline materials that have emerged in recent years, composed of three types of porous crystal materials, namely metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hydrogen-bonded organic frameworks (HOFs). The combination of various organic framework properties in hybrid organic frameworks generates synergistic effects, which has attracted widespread attention from researchers. The synthesis methods of hybrid organic frameworks are also an intriguing topic, enabling the formation of core-shell heterostructures through epitaxial growth, template conversion, medium growth, or direct combination. These hybrid organic framework materials have demonstrated remarkable performance in the application of photocatalytic wastewater purification and have developed various forms of applications. This article reviews the preparation principles and methods of various hybrid organic frameworks and provides a detailed overview of the research progress of photocatalytic water purification hybrid organic frameworks. Finally, the challenges and development prospects of hybrid organic framework synthesis and their application in water purification are briefly discussed.

Synthesis and activation of pH-sensitive metal-organic framework Sr(BDC)∞ for oral drug delivery

Metal-organic frameworks (MOFs) are widely used in the biomedical industry. In this study, we developed a new method for obtaining a metal-organic structure of strontium and terephthalic acid, Sr(BDC), and an alternative activation method for removing DMF from the pores. Sr(BDC) MOFs were successfully prepared and characterized by XRD, FTIR, TGA, and SEM. The importance of the activation steps was confirmed by TGA, which showed that the Sr(BDC)(DMF) sample can contain up to a quarter of the solvent (DMF) before activation. In our study, IR spectroscopy confirmed the possibility of removing DMF by ethanol treatment from the Sr-BDC crystals. A comparative analysis of the effect of the activation method on the specific surface and pore size of Sr-BDC and its sorption properties using the model drug doxorubicin showed that due to the undeveloped surface of the Sr-(BDC)(DMF) sample, it is not possible to obtain an adsorption isotherm and determine the pore size distribution, thus showing the importance of the activation step. Cytotoxicity and apoptosis assays were carried out to study the biological activity of MOFs, and we observed relatively low toxicity in the tested concentration range after 48 h, with over 92% cell survival for Sr(BDC)(DMF) and Sr(BDC)(260 °C), with a decrease only in the highest concentration (800 mg L-1). Similar results were observed in our apoptosis assays, as they revealed low apoptotic population generation of 2.52%, 3.23%, and 2.77% for Sr(BDC)(DMF), Sr(BDC) and Sr(BDC)(260 °C), respectively. Overall, the findings indicate that ethanol-activated Sr(BDC) shows potential as a safe and effective material for drug delivery.

Detection mechanism and the outlook of metal-organic frameworks for the detection of hazardous substances in milk

Milk has a high nutritional value. However, milk is easily contaminated in the production, processing, and storage processes, which harms consumers' health. Therefore, the harmful substances' detection in milk is important. Metal-organic frameworks (MOFs) have proven high potential in food safety detection due to their unique porous structure, large effective surface area, large porosity, and structural tunability. This article systematically describes the detection mechanism of fluorescence, electrochemical, colorimetric, and enzyme-linked immunosorbent assay based on MOFs. The progress of the application of MOFs in the detection of antibiotics, harmful microorganisms and their toxins, harmful ions, and other harmful substances in milk in recent years is reviewed. The structural tunability of MOFs enables them to be functionalized, giving the ability to be applied to different detection methods or substances. Therefore, MOFs can be used as an advantageous sensing material for detecting harmful substances in the complex environment of milk.

Multi-Enzyme Activity of MIL-101 (Fe)-Derived Cascade Nano-Enzymes for Antitumor and Antimicrobial Therapy

The clinical application of oncology therapy is hampered by high glutathione concentrations, hypoxia, and inefficient activation of cell death mechanisms in cancer cells. In this study, Fe and Mo bimetallic sulfide nanomaterial (FeS2 @MoS2 ) based on metal-organic framework structure is rationally prepared with peroxidase (POD)-, catalase (CAT)-, superoxide dismutase (SOD)-like activities and glutathione depletion ability, which can confer versatility for treating tumors and mending wounds. In the lesion area, FeS2 @MoS2 with SOD-like activity can facilitate the transformation of superoxide anions (O2 - ) to hydrogen peroxide (H2 O2 ), and then the resulting H2 O2 serves as a substrate for the Fenton reaction with FMS to produce highly toxic hydroxyl radicals (∙OH). Simultaneously, FeS2 @MoS2 has an ability to deplete glutathione (GSH) and catalyze the decomposition of nicotinamide adenine dinucleotide phosphate (NADPH) to curb the regeneration of GSH from the source. Thus it can realize effective tumor elimination through synergistic apoptosis-ferroptosis strategy. Based on the alteration of the H2 O2 system, free radical production, glutathione depletion and the alleviation of hypoxia in the tumor microenvironment, FeS2 @MoS2 NPS can not only significantly inhibit tumors in vivo and in vitro, but also inhibit multidrug-resistant bacteria and hasten wound healing. It may open the door to the development of cascade nanoplatforms for effective tumor treatment and overcoming wound infection.

All-in-one HN@Cu-MOF nanoparticles with enhanced reactive oxygen species generation and GSH depletion for effective tumor treatment

Non-invasive cancer therapies, especially those based on reactive oxygen species, including photodynamic therapy (PDT), have gained much interest. As emerging photodynamic nanocarriers, metal-organic frameworks (MOFs) based on porphyrin can release reactive oxygen species (ROS) to destroy cancer cells. However, due to the inefficient production of ROS by photosensitizers and the over-expression of glutathione (GSH) in the tumor microenvironment (TME), their therapeutic effect is not satisfactory. Therefore, herein, we developed a multi-functional nanoparticle, HN@Cu-MOF, to enhance the efficacy of PDT. We combined chemical dynamic therapy (CDT) and nitric oxide (NO) therapy by initiating sensitization to PDT and cell apoptosis in the treatment of tumors. The Cu2+-doped MOF reacted with GSH to form Cu+, exhibiting a strong CDT ability to generate hydroxyl radicals (˙OH). The Cu-MOF was coated with HN, which is hyaluronic acid (HA) modified by a nitric oxide donor. HN can target tumor cells over-expressing the CD44 receptor and consume GSH in the cells to release NO. Both cell experiments and in vivo experiments showed an excellent tumor inhibitory effect upon the treatment. Overall, the HN@Cu-MOF nanoparticle-integrated NO gas therapy and CDT with PDT led to a significant enhancement in GSH consumption and a remarkable elevation in ROS production.

Current status of Fe-based MOFs in biomedical applications

Recently nanoparticle-based platforms have gained interest as drug delivery systems and diagnostic agents, especially in cancer therapy. With their ability to provide preferential accumulation at target sites, nanocarrier-constructed antitumor drugs can improve therapeutic efficiency and bioavailability. In contrast, metal-organic frameworks (MOFs) have received increasing academic interest as an outstanding class of coordination polymers that combine porous structures with high drug loading via temperature modulation and ligand interactions, overcoming the drawbacks of conventional drug carriers. FeIII-based MOFs are one of many with high biocompatibility and good drug loading capacity, as well as unique Fenton reactivity and superparamagnetism, making them highly promising in chemodynamic and photothermal therapy, and magnetic resonance imaging. Given this, this article summarizes the applications of FeIII-based MOFs in three significant fields: chemodynamic therapy, photothermal therapy and MRI, suggesting a logical route to new strategies. This article concludes by summarising the primary challenges and development prospects in these promising research areas.

Multifunctional nano MOF drug delivery platform in combination therapy

Recent preclinical and clinical studies have demonstrated that for cancer treatment, combination therapies are more effective than monotherapies in reducing drug-related toxicity, decreasing drug resistance, and improving therapeutic efficacy. With the rapid development of nanotechnology, the combination of metal-organic frameworks (MOFs) and multi-mode therapy offers a realistic possibility to further improve the shortcomings of cancer treatment. This article focuses on the latest developments, achievements, and treatment strategies of representative multifunctional MOF combination therapies for cancer treatment in recent years, which include not only bimodal combination therapies, but also multi-modal synergistic therapies, further demonstrating the effectiveness and superiority of the MOF drug delivery systems in cancer treatment.

Recent advances and prospects of metal-organic frameworks in cancer therapies

Metal-organic frameworks (MOFs) have been broadly applied in biomedical and other fields. MOFs have high porosity, a large comparative area, and good biostability and have attracted significant attention, especially in cancer therapies. This paper presents the latest applications of MOFs in chemodynamic therapy (CDT), sonodynamic therapy (SDT), photodynamic therapy (PDT), photothermal therapy (PTT), immunotherapy (IT), and combination therapy for breast cancer. A combination therapy is the combination of two different treatment modalities, such as CDT and PDT combination therapy, and is considered more effective than separate therapies. Herein, we have also discussed the advantages and disadvantages of combination therapy in the treatment of breast cancer. This paper aims to illustrate the potential of MOFs in new cancer therapeutic approaches, discuss their potential advantages, and provide some reflections on the latest research results.

Current status and prospect of ZIF-based materials for breast cancer treatment

Breast cancer, one of the three most life-threatening cancers in modern times, must be explored for treatments with low side effects and practical efficacy. Metal organic framework materials (MOFs) is made by metal ions as the center for point and organic ligands as a bridge connecting a new type of porous nano-materials, among them, the zinc base zeolite imidazole skeleton material series (ZIFs) because of its excellent biocompatibility and pH slow controlled release ability, is widely used in the tumor microenvironment in basic research and achieved remarkable curative effect. Inspired by this, in this review, we focus on the recent research progress on the application of ZIFs in the treatment of breast cancer, mainly studying the structure of ZIFs such as ZIF-8, ZIF-90 and ZIF-67 and their application in novel therapies for breast cancer treatment, such as targeted drug delivery, photothermal therapy, immunotherapy and gene therapy.We will more fully demonstrate the potential of zif in breast cancer treatment, hoping to provide an avenue for exploring breast cancer treatment.

Recent advances in the nanoarchitectonics of metal-organic frameworks for light-activated tumor therapy

Metal-organic frameworks (MOFs) have received extensive attention in tumor therapy because of their advantages, including large specific surface area, regular pore size, adjustable shape, and facile functionalization. MOFs are porous materials formed by the coordination bonding of metal clusters and organic ligands. This review summarized the most recent advancements in tumor treatment based on nMOFs. First, we discuss the classification of MOFs, which primarily include the series of isoreticular MOF (IRMOF), zeolitic imidazolate framework (ZIF), coordination pillared-layer (CPL), Materials of Institute Lavoisier (MIL), porous coordination network (PCN), University of Oslo (UiO) and Biological metal-organic frameworks (BioMOFs). Then, we discuss the use of nMOFs in antitumor therapy, including drug delivery strategies, photodynamic therapy (PDT), photothermal therapy (PTT), and combination therapy. Finally, the obstacles and opportunities in nMOFs are discussed.

Targeted Delivery of 5-Fluorouracil and Sonidegib via Surface-Modified ZIF-8 MOFs for Effective Basal Cell Carcinoma Therapy

The therapeutic effectiveness of the most widely used anticancer drug 5-fluorouracil (5-FU) is constrained by its high metabolism, short half-life, and rapid drug resistance after chemotherapy. Although various nanodrug delivery systems have been reported for skin cancer therapy, their retention, penetration and targeting are still a matter of concern. Hence, in the current study, a topical gel formulation that contains a metal-organic framework (zeolitic imidazole framework; ZIF-8) loaded with 5-FU and a surface modified with sonidegib (SDG; acting as a therapeutic agent as well as a targeting ligand) (5-FU@ZIF-8 MOFs) is developed against DMBA-UV-induced BCC skin cancer in rats. The MOFs were prepared using one-pot synthesis followed by post drug loading and SDG conjugation. The optimized MOFs were incorporated into hyaluronic acid-hydroxypropyl methyl cellulose gel and further subjected to characterization. Enhanced skin deposition of the 5-FU@ZIF-8-SDG MOFs was observed using ex vivo skin permeation studies. Confocal laser microscopy studies showed that 5-FU@ZIF-8-SDG MOFs permeated the skin via the transfollicular pathway. The 5-FU@ZIF-8-SDG MOFs showed stronger cell growth inhibition in A431 cells and good biocompatibility with HaCaT cells. Histopathological studies showed that the efficacy of the optimized MOF gels improved as the epithelial cells manifested modest hyperplasia, nuclear pleomorphism, and dyskeratosis. Additionally, immunohistochemistry and protein expression studies demonstrated the improved effectiveness of the 5-FU@ZIF-8-SDG MOFs, which displayed a considerable reduction in the expression of Bcl-2 protein. Overall, the developed MOF gels showed good potential for the targeted delivery of multifunctional MOFs in topical formulations for treating BCC cancer.

ZIF-67-Derived Co/N-Doped Carbon-Functionalized MXene for Enhanced Electrochemical Sensing of Carbendazim

Herein, ZIF-67-derived Co and N-doped carbon (Co/NC) particle-modified multilayer MXene (MXene@Co/NC) was developed as remarkable electrode material for carbendazim (CBZ) detection. MXene as a substrate provides an excellent conductive framework and plentiful accessibility sites. Co/NC particles embedding in MXene can not only prevent the interlayer stacking of MXene but also contribute a great deal of metal catalytic active sites and finally improve the adsorption and catalytic properties of the composite. Accordingly, the MXene@Co/NC electrode displays excellent electrocatalytic activity toward CBZ oxidation. Experimental parameters such as pH value, accumulation time, MXene@Co/NC modification volume and constituent materials' mass ratios were optimized. Under optimal conditions, the as-prepared sensor based on MXene@Co/NC holds a broad linearity range from 0.01 μM to 45.0 μM with a low limit of detection (LOD) of 3.3 nM (S/N = 3, S means the detection signal, while N represents the noise of the instrument). Moreover, the proposed sensor displays excellent anti-interference ability, superior reproducibility, excellent stability, and successfully achieves actual applications for CBZ detection in a lettuce sample.

New Transition Metal Coordination Polymers Derived from 2-(3,5-Dicarboxyphenyl)-6-carboxybenzimidazole as Photocatalysts for Dye and Antibiotic Decomposition

Coordination polymers (CPs) are an assorted class of coordination complexes that are gaining attention for the safe and sustainable removal of organic dyes from wastewater discharge by either adsorption or photocatalytic degradation. Herein, three different coordination polymers with compositions [Ni(HL)(H2O)2·1.9H2O] (1), [Mn3(HL)(L)(μ3-OH)(H2O)(phen)2·2H2O] (2), and [Cd(HL)4(H2O)]·H2O (3) (H3L = 2-(3,5-dicarboxyphenyl)-6-carboxybenzimidazole; phen = 1,10-phenanthroline) have been synthesized and characterized spectroscopically and by single crystal X-ray diffraction. Single crystal X-ray diffraction results indicated that 1 forms a 2D layer-like framework, while 2 exhibits a 3-connected net with the Schläfli symbol of (44.6), and 3 displays a 3D supramolecular network in which two adjacent 2D layers are held by π···π interactions. All three compounds have been used as photocatalysts to catalyze the photodegradation of antibiotic dinitrozole (DTZ) and rhodamine B (RhB). The photocatalytic results suggested that the Mn-based CP 2 exhibited better photodecomposition of DTZ (91.1%) and RhB (95.0%) than the other two CPs in the time span of 45 min. The observed photocatalytic mechanisms have been addressed using Hirshfeld surface analyses.

New 5,5-(1,4-Phenylenebis(methyleneoxy)diisophthalic Acid Appended Zn(II) and Cd(II) MOFs as Potent Photocatalysts for Nitrophenols

Metal-organic frameworks (MOFs) are peculiar multimodal materials that find photocatalytic applications for the decomposition of lethal molecules present in the wastewater. In this investigation, two new d10-configuration-based MOFs, [Zn2(L)(H2O)(bbi)] (1) and [Cd2(L)(bbi)] (2) (5,5-(1,4-phenylenebis(methyleneoxy)diisophthalic acid (H2L) and 1,1'-(1,4-butanediyl)bis(imidazole) (bbi)), have been synthesized and characterized. The MOF 1 displayed a (4,6)-connected (3.43.52)(32.44.52.66.7) network topology, while 2 had a (3,10)-connected network with a Schläfli symbol of (410.511.622.72)(43)2. These MOFs have been employed as photocatalysts to photodegrade nitrophenolic compounds, especially p-nitrophenol (PNP). The photocatalysis studies reveal that 1 displayed relatively better photocatalytic performance than 2. Further, the photocatalytic efficacy of 1 has been assessed by altering the initial PNP concentration and photocatalyst dosage, which suggest that at 80 ppm PNP concentration and at its 50 mg concentration the MOF 1 can photo-decompose around 90.01% of PNP in 50 min. Further, radical scavenging experiments reveal that holes present over 1 and ·OH radicals collectively catalyze the photodecomposition of PNP. In addition, utilizing density of states (DOS) calculations and Hirshfeld surface analyses, a plausible photocatalysis mechanism for nitrophenol degradation has been postulated.

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.

A New Cd(II)-Based Coordination Polymer for Efficient Photocatalytic Removal of Organic Dyes

Coordination polymers (CPs) are a diverse class of multi-dimensional compounds that show promise as photocatalysts for degrading dyes in polluted water. Herein, a new 1D Cd(II)-based coordination polymer with the formula [Cd(bpyp)(nba)2] (1) (bpyp = 2,5-bis(pyrid-4-yl)pyridine and Hnba = 4-nitrobenzoic acid) is synthesized and characterized. In 1, the two carboxyl groups of two different nba- ligands show μ2-η1:η1 and μ1-η1:η1 coordination modes to connect the CdII centers and sit on either side of the chain along the b direction. The produced CP 1 was utilized as the photocatalyst in the process of the photodegradation of methyl blue (MB), methyl orange (MO), rhodamine B (RhB), and methyl violet (MV) dyes when exposed to UV light. The photocatalytic degradation activities of CP 1 were analyzed, and the results suggest that it exhibits an extraordinary efficiency in the degradation of MB, MV, MO, and RhB. RhB has a 95.52% efficiency of degradation, whereas MV has a 58.92% efficiency, MO has 35.44%, and MB has 29.24%. The photodecomposition of dyes is catalyzed mostly by •O2- and •OH-, as shown by research involving the trapping of radicals.

Hydrogen-Bonded Organic Frameworks Chelated Manganese for Precise Magnetic Resonance Imaging Diagnosis of Cancers

Magnetic resonance imaging (MRI) is an important tool in the diagnosis of many cancers. However, clinical gadolinium (Gd)-based MRI contrast agents have limitations, such as large doses and potential side effects. To address these issues, we developed a hydrogen-bonded organic framework-based MRI contrast agent (PFC-73-Mn). Due to the hydrogen-bonded interaction of water molecules and the restricted rotation of manganese ions, PFC-73-Mn exhibits high longitudinal relaxation r1 (5.03 mM-1 s-1) under a 3.0 T clinical MRI scanner. A smaller intravenous dose (8 μmol of Mn/kg) of PFC-73-Mn can provide strong contrast and accurate diagnosis in multiple kinds of cancers, including breast tumor and ultrasmall orthotopic glioma. PFC-73-Mn represents a prospective new approach in tumor imaging, especially in early-stage cancer.

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.

Fluorescence detection platform of metal-organic frameworks for biomarkers

Sensitive and selective detection of biomarkers is crucial in the study and early diagnosis of diseases. With the continuous development of biosensing technologies, fluorescent biosensors based on metal-organic frameworks have attracted increasing attention in the field of biomarker detection due to the combination of the advantages of MOFs, such as high specific surface area, large porosity, and structure with tunable functionality and the technical simplicity, sensitivity and efficiency and good applicability of fluorescent detection techniques. Therefore, researchers must understand the fluorescence response mechanism of such fluorescent biosensors and their specific applications in this field. Of all biomarkers applicable to such sensors, the chemical essence of nucleic acids, proteins, amino acids, dopamine, and other small molecules account for about a quarter of the total number of studies. This review systematically elaborates on four fluorescence response mechanisms: metal-centered emission (MC), ligand-centered emission (LC), charge transfer (CT), and guest-induced luminescence change (GI), presenting their applications in the detection of nucleic acids, proteins, amino acids, dopamine, and other small molecule biomarkers. In addition, the current challenges of MOFs-based fluorescent biosensors are also discussed, and their further development prospects are concerned.

Heterometallic ZnHoMOF as a Dual-Responsive Luminescence Sensor for Efficient Detection of Hippuric Acid Biomarker and Nitrofuran Antibiotics

Developing efficient and sensitive MOF-based luminescence sensors for bioactive molecule detection is of great significance and remains a challenge. Benefiting from favorable chemical and thermal stability, as well as excellent luminescence performance, a porous Zn(II)Ho(III) heterometallic-organic framework (ZnHoMOF) was selected here as a bifunctional luminescence sensor for the early diagnosis of a toluene exposure biomarker of hippuric acid (HA) through "turn-on" luminescence enhancing response and the daily monitoring of NFT/NFZ antibiotics through "turn-off" quenching effects in aqueous media with high sensitivity, acceptable selectivity, good anti-interference, exceptional recyclability performance, and low detection limits (LODs) of 0.7 ppm for HA, 0.04 ppm for NFT, and 0.05 ppm for NFZ. Moreover, the developed sensor was employed to quantify HA in diluted urine samples and NFT/NFZ in natural river water with satisfactory results. In addition, the sensing mechanisms of ZnHoMOF as a dual-response chemosensor in efficient detection of HA and NFT/NFZ antibiotics were conducted from the view of photo-induced electron transfer (PET), as well as inner filter effects (IFEs), with the help of time-dependent density functional theory (TD-DFT) and spectral overlap experiments.

Metal-Organic Framework/Polyvinyl Alcohol Composite Films for Multiple Applications Prepared by Different Methods

The incorporation of different functional fillers has been widely used to improve the properties of polymeric materials. The polyhydroxy structure of PVA with excellent film-forming ability can be easily combined with organic/inorganic multifunctional compounds, and such an interesting combining phenomenon can create a variety of functional materials in the field of materials science. The composite membrane material obtained by combining MOF material with high porosity, specific surface area, and adjustable structure with PVA, a non-toxic and low-cost polymer material with good solubility and biodegradability, can combine the processability of PVA with the excellent performance of porous filler MOFs, solving the problem that the poor machinability of MOFs and the difficulty of recycling limit the practical application of powdered MOFs and improving the physicochemical properties of PVA, maximizing the advantages of the material to develop a wider range of applications. Firstly, we systematically summarize the preparation of MOF/PVA composite membrane materials using solution casting, electrostatic spinning, and other different methods for such excellent properties, in addition to discussing in detail the various applications of MOF/PVA composite membranes in water treatment, sensing, air purification, separation, antibacterials, and so on. Finally, we conclude with a discussion of the difficulties that need to be overcome during the film formation process to affect the performance of the composite film and offer encouraging solutions.

Green Ultrasound-Assisted Synthesis of Rare-Earth-Based MOFs

Rare-earth (RE)-based metal organic frameworks (MOFs) are quickly gaining popularity as flexible functional materials in a variety of technological fields. These MOFs are useful for more than just conventional uses like gas sensors and catalyst materials; in fact, they also show significant promise in emerging technologies including photovoltaics, optical, and biomedical applications. Using yttrium and europium as ionic host centres and dopants, respectively, and 1,3,5-benzenetricarboxylic acid (H3-BTC) as an organic linker, we describe a simple and green approach for the fabrication of RE-MOFs. Specifically, Y-BTCs and Eu-doped Y-BTCs MOFs have been synthesised in a single step using an eco-friendly method that makes use of ultrasound technology. To establish a correlation between the morphological and structural properties and reaction conditions, a range of distinct reaction periods has been employed for the synthetic processes. Detailed analyses of the synthesised samples through powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR) have confirmed the phase formation. Furthermore, thermal analyses such as thermogravimetric analysis (TGA) have been employed to evaluate the thermal stability and structural modifications of the Y-BTC and Eu-doped Y-BTC samples. Finally, the luminescent properties of the synthesised samples doped with Eu3+ have been assessed, providing an evaluation of their characteristics. As a proof of concept, an Eu-doped Y-BTC sample has been applied for the sensing of nitrobenzene as a molecule test of nitro derivatives.

Current status of porous coordination networks (PCNs) derived porphyrin spacers for cancer therapy

INTRODUCTION

Porous coordination networks (PCNs) have been widely used in large number of applications such as light harvesting, catalysis, and biomedical applications. Inserting porphyrins into PCNs scaffolds can alleviate the solubility and chemical stability problems associated with porphyrin ligands and add functionality to PCNs. The discovery that some PCNs materials have photosensitizer and acoustic sensitizer properties has attracted significant attention in the field of biomedicine, particularly in cancer therapy. This article describes the latest applications of the porphyrin ligand-based family of PCNs in cancer chemodynamic therapy (CDT), photodynamic therapy (PDT), sonodynamic therapy (SDT), photothermal therapy (PTT), and combination therapies and offers some observations and reflections on them.

AREAS COVERED

This article discusses the use of the PCN family of MOFs in cancer treatment, specifically focusing on chemodynamic therapy, sonodynamic therapy, photodynamic therapy, photothermal therapy, and combination therapy.

EXPERT OPINION

Although a large number of PCNs have been developed for use in novel cancer therapeutic approaches, further improvements are needed to advance the use of PCNs in the clinic. For example, the main mechanism of action of PCNs against cancer and the metabolic processes in organisms, and how to construct PCNs that maintain good stability in the complex environment of organisms.