Zeolitic Imidazolate Framework Research Articles

The enhanced oxidase-like activity of modified nanoceria/ZIF-67 for fluorescence and smartphone-assisted visual detection of tannic acid

As a substitute for natural enzymes, nanozymes have unique characteristics of high catalytic activity, excellent stability and low cost, making them pivotal in sensing applications. Among them, nanozymes with oxidase-like activity garner significant attention for antioxidant detection, as they efficiently catalyze the oxidation of antioxidants in the presence of oxygen. Herein, a nanozyme with an enhanced oxidase-like activity was synthesized through a 3-step strategy, that is, ceria nanoparticles were firstly modified with amino acid and oligopeptides, then combined with zeolitic imidazolate framework-67 (ZIF-67), and finally the composite was etched in neutral water. The as-synthesized nanozyme can oxidize the substrate 3,3′,5,5′-tetramethylbenzidine (TMB) or Amplex Red (AR) in the presence of oxygen, inducing a change in their color or fluorescent signals, verifying its oxidase-like activity. Tannic acid (TA), an antioxidant, competes with TMB/AR for oxidation by the nanozyme. Leveraging this competitive relationship, a fluorescent and portable trichromatic sensor was developed for the detection of tannic acid (TA) in food samples. The fluorescent sensor shows high sensitivity with detection limits (S/N = 3) of 0.011 µM, and the trichromatic sensor presents comparable performance to colorimetric sensor, exhibiting a linear range of 30–270 µM and detection limit of 1.03 µM. By using a smartphone platform, the trichromatic sensor enables convenient, rapid, inexpensive, and quantitative assessment of TA. Both two sensors were successfully applied to TA detection in 9 different foods. This study not only provides an effective strategy to enhance enzyme performance but also paves the way for their applications in food testing.

Self-Reinforced MOF-Based Nanogel Alleviates Osteoarthritis by Long-Acting Drug Release.

Intra-articular injection of drugs is an effective strategy for osteoarthritis (OA) treatment. However, the complex microenvironment and limited joint space result in rapid clearance of drugs. Herein, a nanogel-based strategy is proposed for prolonged drug delivery and microenvironment remodeling. Nanogel is constructed through the functionalization of hyaluronic acid (HA) by amide reaction on the surface of Kartogenin (KGN)-loaded zeolitic imidazolate framework-8 (denoted as KZIF@HA). Leveraging the inherent hydrophilicity of HA, KZIF@HA spontaneously forms nanogels, ensuring extended drug release in the OA microenvironment. KZIF@HA exhibits sustained drug release over one month, with low leakage risk from the joint cavity compared to KZIF, enhanced cartilage penetration, and reparative effects on chondrocytes. Notably, KGN released from KZIF@HA serves to promote extracellular matrix (ECM) secretion for hyaline cartilage regeneration. Zn2+ release reverses OA progression by promoting M2 macrophage polarization to establish an anti-inflammatory microenvironment. Ultimately, KZIF@HA facilitates cartilage regeneration and OA alleviation within three months. Transcriptome sequencing validates that KZIF@HA stimulates the polarization of M2 macrophages and secretes IL-10 to inhibit the JNK and ERK pathways, promoting chondrocytes recovery and enhancing ECM remodeling. This pioneering nanogel system offers new therapeutic opportunities for sustained drug release, presenting a significant stride in OA treatment strategies.

Biomimetic cell membrane decorated ZIF‐8 nanocarriers with IR‐780 and doxorubicin loading for multiple myeloma treatment

AbstractSeveral therapeutic drugs including heptamethine cyanine dye (IR‐780), doxorubicin (DOX), and others have exhibited positive outcomes in the treatment of multiple myeloma (MM). However, curing MM is still hampered by undesired off‐target effects and uncontrolled release of the therapeutics. Herein, we present novel MM‐mimicking nanocarriers by integration of DOX, IR‐780, and MM cell membrane with zeolitic imidazolate framework‐8 (ZIF‐8) nanoparticles (D/INPs@CM) for MM treatment. The nanocarriers were fabricated by co‐loading DOX and IR‐780 into ZIF‐8 and further coated with the cell membrane. After intravenous injection, the D/INPs@CM can enter the bone marrow and target the tumor cells owing to bone marrow homing and homologous targeting properties of the MM cell membrane. Once accumulating in the tumor site, ZIF‐8 decomposed under the acid microenvironment and released the encapsulated DOX and IR‐780. As a result, D/INPs@CM showed the best MM tumor eradication performance compared to D/INPs, without displaying noticeable systemic toxicity. All these features suggest that our biomimetic nanocarriers may have great potential for the precise and targeted therapy of MM and related other hematological malignancies.

Dual-MOFs-cage constructed multistage-channel PVDF-HFP quasi-solid electrolytes for lithium metal battery

As the candidate for electrolyte in lithium metal batteries, quasi-solid electrolytes have been affected by the growth of lithium dendrites and the continuous reaction between lithium and electrolyte. Herein, we introduce a quasi-solid electrolyte, ZIF-67@ZIF-8/PVDF-HFP (PHMx), with multi-stage ion transport channels. Additionally, we have developed Zeolitic Imidazolate Frameworks (ZIFs) materials that possess a “cage” structure, which is defined as dual-MC nanoparticles. PVDF-HFP in PHMx serves as mechanical backbone, with dual-MC nanoparticles densely and uniformly distributed within the PVDF-HFP. The synergistic effect of the microporous structure of the PVDF-HFP and that of the dual-MC nanoparticles is utilized to construct multi-stage ion transport channels. PHM9 achieves uniform Li+ deposition and inhibits the continuous reaction between lithium and electrolyte. Therefore, PHM9, not only achieves high ionic conductivity of 3.2 × 10−3 S cm−1 but also remains stable for 1600 h during Lithium-symmetric cycling. Lithium metal battery, assembled with LiFePO4 as the cathode material, exhibited stable cycling for 400 cycles at a rate of 0.2 C, demonstrating a capacity retention rate of 86.6 %. Similarly, the lithium metal battery utilizing LiCoO2 as the cathode material demonstrated stable cycling for 200 cycles at a rate of 0.2 C, exhibiting an impressive capacity retention rate of 96.7 %.

Investigating the Catalytic Effect of a Zeolitic Imidazolate Framework, ZIF-8, on the Phase Transition and Thermal Decomposition of Ammonium Nitrate

Investigating the Catalytic Effect of a Zeolitic Imidazolate Framework, ZIF-8, on the Phase Transition and Thermal Decomposition of Ammonium Nitrate

Crizotinib resistance reversal in ALK-positive lung cancer through zeolitic imidazolate framework-based mitochondrial damage

Crizotinib (CRZ), one of anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs), has emerged as a frontline treatment for ALK-positive (ALK+) lung adenocarcinoma. However, the overexpression of P-glycoprotein (P-gp, a mitochondrial adenosine triphosphate (ATP)-dependent protein) in lung adenocarcinoma lesions causes multidrug resistance (MDR) and limits the efficacy of CRZ treatment. Herein, a mitochondria-targeting nanosystem, zeolitic imidazolate framework-90@indocyanine green (ZIF-90@ICG), was fabricated to intervene in mitochondria and overcome drug resistance. Due to the zinc ion (Zn2+) interference of ZIF-90 and the photodynamic therapy (PDT) of ICG, this nanosystem is well suited for damaging mitochondrial functions, thus downregulating the intracellular ATP level and inhibiting P-gp expression. In addition, systematic bioinformatics analysis revealed the upregulation of CD44 in CRZ-resistant cells. Therefore, hyaluronic acid (HA, a critical target ligand of CD44) was further modified on the surface of ZIF-90@ICG for active targeting. Overall, this ZIF-90@ICG nanosystem synergistically increased the intracellular accumulation of CRZ and reversed CRZ resistance to enhance its anticancer effect, which provides guidance for nanomedicine design to accurately target tumours and induce mitochondrial damage and represents a viable regimen for improving the prognosis of patients with ALK-TKIs resistance. Statement of significanceThe original aim of our research was to combat multidrug resistance (MDR) in highly aggressive and lethal lymphoma kinase-positive (ALK+) lung adenocarcinoma. For this purpose, a cascade-targeted system was designed to overcome MDR, integrating lung adenocarcinoma-targeted hyaluronic acid (HA), mitochondrion-targeted zeolitic imidazolate framework-90 (ZIF-90), the clinically approved drug crizotinib (CRZ), and the fluorescence imaging agent/photosensitizer indocyanine green (ICG). Moreover, using a “two birds with one stone” strategy, ion interference and oxidative stress induced by ZIF-90 and photodynamic therapy (PDT), respectively, disrupt mitochondrial homeostasis, thus downregulating adenosine triphosphate (ATP) levels, inhibiting MDR-relevant P-glycoprotein (P-gp) expression and suppressing tumour metastasis. Overall, this research represents an attempt to implement the concept of MDR reversal and realize the trade-offs between MDR and therapeutic effectiveness.

Electrochemical Kinetic Behaviors and Sensing Performance of Au@ZIF-8 and Ag@ZIF-8 Nanocomposites-Based Platforms Towards Ultrasensitive Detection of Chloramphenicol

Silver (Ag) and gold (Au) nanoparticles (NPs) are incorporated into the zeolitic imidazolate framework-8 (ZIF-8) host matrix, which is successfully coated the screen-printed electrodes (SPEs) for the effective detection of chloramphenicol (CAP). The morphological and structural characteristics are examined using scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. Additionally, the electrochemical characteristics and sensing performance of CAP on the proposed electrodes are investigated in detail using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and differential pulse voltammetry (DPV) measurements, respectively. The results suggest the SPEs modified with Ag@ZIF-8 and Au@ZIF-8 exhibit impressive enhancements in sensitivity, linear concentration range, limits of detection (LODs), and repeatability. Under the optimum conditions, the proposed electrochemical sensors had a linear range of 0.25–50 μM for Ag@ZIF-8/SPE and 5–50 μM for Au@ZIF-8/SPE, corresponding to LODs of 0.16 and 0.404 μM, respectively. Notably, a series of kinetic parameters related to the redox reactions of both standard Fe(CN)6 3−/4− probe and CAP molecules in phosphate-buffered saline (PBS) buffer are determined. Furthermore, valuable insights into the influence mechanism nature of Ag@ZIF-8 and Au@ZIF-8 nanocomposites on the electrochemical behaviors are proposed, demonstrating the great potential of the developed sensors for CAP detection.

Synergistic effect in ZIF-67/MoS2 entrenched MWCNT photo (electro) catalyst for degradation of tetracycline and alternative to Pt counter electrode in dye-sensitized solar cells

Photocatalytic water purification is an effective environmental protection approach for removing hazardous chemicals in water, besides solar energy conversion is a trustworthy and sustainable choice for the future due to rising energy demands. The present research focus is on synthesis of Metal-Organic Framework (MOF) based composite, Zeolitic Imidazolate Framework-67/Molybdenum Disulfide (ZIF-67/MoS2) entrenched Multi-Walled Carbon Nanotubes (MWCNT) as a catalyst for photodegradation of tetracycline (TC), as well as substitute for Pt counter electrode in Dye-Sensitized Solar Cell (DSSC). The crystalline structure, optical response, shape, porosity, quantum states, and chemical configuration were determined using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Photoluminescence spectroscopy (PL), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), and X-ray Photoelectron Spectroscopy (XPS), respectively. The degradation efficiency of ZIF-67/MoS2/MWCNT catalyst under effect of operational parameters namely, photocatalyst dosage, solution pH, coexisting ions, TC concentrations and irradiation time were studied consecutively. ZIF-67/MoS2/MWCNT composite achieved 96.1 % degradation efficiency of TC under white light irradiation. Interestingly, when utilized as a counter electrode in DSSCs, this composite-based electrode delivered the highest Power Conversion Efficiency (PCE) of 3.86 % with a short-circuit current density (JSC) of 7.54 mA cm−2 and open-circuit voltage (VOC) of 0.79 V. The observed enhancement is attributed to lesser peak-to-peak separation (EPP), lower electron lifetime, lower charge transfer resistance (RCT) and higher exchange current density (J0). Based on these findings, ZIF-67 inclusion in MoS2/MWCNT composite is not only an effective catalyst for water treatment but also a good catalyst for I3− reduction in DSSCs.

Flexible, breathable, and durable superhydrophobic cotton fabric modified by behenic acid, tung oil, and ZIF-8 with anti-icing and self-cleaning properties.

Textiles with self-cleaning and anti-icing capabilities in cold climates are essential for outdoor workers and enthusiasts. Superhydrophobic modification of textile surfaces is effective in imparting these characteristics. Although there are numerous methods available for manufacturing superhydrophobic textiles, careful consideration is warranted for environmental concerns over fluorochemicals, stability of superhydrophobic coatings, and fabric breathability. In this work, we utilized biomass resources such as tung oil and behenic acid, along with zeolitic imidazolate framework (ZIF-8), to modify cotton fabrics, thereby creating an innovative behenic acid/tung oil/ZIF-8 modified cotton (BTZC) fabric with anti-icing and self-cleaning features. This material manifests a unique nanoflower-shaped surface morphology, demonstrating exceptional superhydrophobicity with a static water contact angle (CA) of 162° and a sliding angle (SA) of 2°. Moreover, BTZC excels in its thermal stability, breathability, and resistance to icing. Equally impressive is its robust stability, as evidenced through rigorous testing under continuous washing and abrasion, sustained high and low temperatures, extreme pH environments, and immersion in various chemical solvents. BTZC presents as a fluorine-free, durable, economically viable alternative for outdoor textile applications, marking substantial progress in the utilization of biomass and metal-organic framework materials in the textile industry and promising implications for value enhancement.

Enhanced H2S gas sensing utilizing UV-assisted In2O3@ZnO nanosheets

In the realm of environmental protection, there is a growing demand for efficient and environmentally friendly gas sensors. In this study, we employed a simple hydrothermal method to synthesize nanosheets composed of zinc oxide (ZnO)-doped indium oxide (In2O3), utilizing zeolitic imidazolate framework-8 (ZIF-8) as a precursor. These nanosheets demonstrated exceptional sensitivity and selectivity in detecting hydrogen sulfide (H2S) gas. A comprehensive analysis of crystal structure, chemical states, elemental composition, surface area, and morphology was conducted. Brunauer–Emmett–Teller (BET) surface area measurements to assess the materials' textural properties revealed that the nanosheets labeled In2O3/0.1ZnO possessed a high specific surface area of 49.02 m2/g, greater than the 45.65 m2/g of pure In2O3 nanosheets, a crucial factor contributing to the observed exceptional sensitivity and selectivity in detecting H2S gas. Particularly noteworthy is the substantial improvement in gas detection response from 109.9 to 146.2 (approximately 24.7 %) observed in the In2O3/0.1ZnO material under UV irradiation at the optimal temperature of 250 °C. This enhancement emphasizes the material's potential for superior gas detection. The incorporation of ZIF-8-derived ZnO nanostructures played a crucial role in creating additional active sites, further enhancing the gas-sensing capabilities. Importantly, this innovative synthesis technique ensures the production of clean, non-toxic materials, aligning with environmental conservation objectives, and holds promise for achieving heightened sensitivity and selectivity in the detection of environmentally harmful gases.

Synergy of pore confinement and co-catalytic effects in Peroxymonosulfate activation for persistent and selective removal of contaminants

The activation of peroxymonosulfate (PMS) through nanoconfinement and co-catalytic effects has demonstrated considerable promise in environmental remediation. Nevertheless, the attainment of persistent efficiency and specificity for pollutant degradation remains a formidable obstacle. Herein, we proposed a solvent-free molten approach to convert a mixture of zeolitic imidazolate frameworks (ZIFs) and MoS2 into 3D integrated cobalt-molybdenum bimetallic nitrogen-doped porous carbon foam with catalytic/co-catalytic performance (MC@NCF). The integrated materials exhibited exceptional efficiency in degrading contaminants based on the synergy of pore confinement and co-catalytic effects, achieving almost 100 % tetracycline degradation in 10 min with a k-value as high as 112.44 min−1·M−1, which was superior to the existing catalysts reported so far. The experimental findings revealed that the structural adjustment of MC@NCF significant accelerated the mass transfer through the formation of interfacial Mo-S/O-Co and Mo-N-Co/C bonds electron-tuning bridges between pore-confined micro-units, leading to the increased singlet oxygen (1O2) yield. Therefore, the MC@NCF exhibited more remarkable stability without interference from coexisting inorganic ions and cations, humic acid, and water matrices. Moreover, a flow-through nanoreactor was constructed and acquired efficient reactivity with negligible biotoxicity, and easy nanocatalyst recycling after continuous operation. The possible reactivity mechanism was identified by Frontier molecular orbital theory HOMO-LUMO, Fukui function, LC-MS, EPR, in-situ ATR-FTIR, and Raman analyses. Our results will guide integrated “catalytic/co-catalytic” nanoconfined MOF derivatives design to further enhance deep water purification technology.

Metal-polyphenol network loaded ZIF-8 for efficient removal of fluoroquinolone antibiotics

A metal-polyphenol network functionalized on surface of zeolitic imidazolate framework-8 (MPN@ZIF-8) were fabricated for efficient removal of fluoroquinolones (FQs) antibiotics. Polyphenol as one kind versatile molecular glue was employed as organic ligand as well as linkage for growth and deposition of metal-polyphenol network (MPN) on ZIF-8 supporter. The prepared MPN@ZIF-8 composite was characterized by various methods. The parameters including the dosage of adsorbents, pH value, adsorption time and salt concentration affecting the adsorption process were systematically investigated. FQs adsorption isotherms and kinetics best fitted the Langmuir isotherm (R2 > 0.980) and pseudo-second-order model (R2 > 0.987), respectively. Thermodynamic studies showed that adsorption process of norfloxacin (NOR), ciprofloxacin (CIP) and enrofloxacin (ENR) were all spontaneous. The adsorption capacity of MPN@ZIF-8 were 104.60, 86.23 and 66.21 mg g−1 for NOR, CIP and ENR, respectively, which were significantly higher than those of precursor ZIF-8. The potential adsorption mechanism was stated, most likely involved in π-π interaction, hydrogen-bond and electrostatic interaction between the FQs and the MPN@ZIF-8. In addition, the removal efficiency of the three FQs on MPN@ZIF-8 was still above 95 % after recycle for four times. The recoveries of the three FQs were in the range of 77.1–100.1 % with RSDs below 7.8 % in real sample analysis. Compared with the methods in preparation of MOF-based composite, the fabrication method mentioned in this study is versatile, very easy, environmental friendly and low cost, which has potential in large-scale production for application in environmental remediation.

ZIF-8-based Nanoparticles for Inflammation Treatment and Oxidative Stress Reduction in Periodontitis.

Periodontitis, an inflammatory bone resorption disease associated with dental plaque, poses significant challenges for effective treatment. In this study, we developed Mino@ZIF-8 nanoparticles inspired by the periodontal microenvironment and the unique properties of zeolitic imidazolate framework 8, aiming to address the complex pathogenesis of periodontitis. Transcriptome analysis revealed the active engagement of Mino@ZIF-8 nanoparticles in innate and adaptive inflammatory host defense and cellular metabolic remodeling. Through sustained release of the anti-inflammatory and antibacterial agent minocycline hydrochloride (Mino) and the generation of Zn2+ with pro-antioxidant effects during degradation, Mino@ZIF-8 nanoparticles synergistically alleviate inflammation and oxidative damage. Notably, our study focuses on the pivotal role of zinc ions in mitochondrial oxidation protection. Under lipopolysaccharide (LPS) stimulation, periodontal ligament cells undergo a metabolic shift from oxidative phosphorylation (OXPHOS) to glycolysis, leading to reduced ATP production and increased reactive oxygen species levels. However, Zn2+ effectively rebalances the glycolysis-OXPHOS imbalance, restoring cellular bioenergetics, mitigating oxidative damage, rescuing impaired mitochondria, and suppressing inflammatory cytokine production through modulation of the AKT/GSK3β/NRF2 pathway. This research not only presents a promising approach for periodontitis treatment but also offers novel therapeutic opportunities for zinc-containing materials, providing valuable insights into the design of biomaterials targeting cellular energy metabolism regulation.

Fabrication of Ni and Cd co-doped Zn ZIF-L photocatalyst for enhanced solar hydrogen evolution

Recently, photocatalytic H2 production has gained significant attention for its potential to generate clean and renewable energy. In this study, the enhancement of H2 production was examined by introducing various transition metal elements in Zn/Ni/Cd zeolitic imidazole frameworks photocatalysts (ZIF). The photocatalysts were synthesized using a precipitation method in water, resulting in the formation of ZIF-L structures. Increasing the Ni content leads to large particle sizes and typically reduced surface areas, owing to the increased possibility of coordination at the six coordination sites of Ni atoms. The trimetallic Zn/Ni/Cd ZIF at its optimum composition exhibits the highest absorbance and narrowest band gap, consequently yielding the highest average H2 production rate. To address unstable reproducibility from restricted electron transfer in the optimal sample, CdS is added to form a heterojunction and to achieve stable reproducibility. Consequently, improved H2 production is achieved by incorporating imidazole organic ligands into the co-doped trimetallic ZIF-L photocatalyst. Overall, in this study, the synthesis and optimization of ZIF composite photocatalysts are elucidated, providing insights into the design of efficient materials for sustainable energy production.

Efficient degradation of levofloxacin using peroxymonosulfate activated by a novel magnetic catalyst derived from waste walnut shell biomass

Developing an economical and efficient catalyst derived from biochar and metal-organic frameworks (MOFs) for the activation of peroxymonosulfate (PMS) to degrade pollutants holds promise for practical applications. Herein, a simple in-situ synthesis method was designed to generate zeolitic imidazole framework with Co-based (ZIF-67) on the surface of waste walnut shell biomass, and novel derived magnetic catalysts (BC@CobC, Biochar@Co base Carbon) were obtained by high-temperature carbonization. This structure could avoid the drawbacks of structural collapse and particle agglomeration of MOF derivatives, while the presence of biochar could accelerate electron transfer and improve the activation performance. For the degradation of levofloxacin, the removal rate in the 0.5-BC@CobC/PMS system reached 89.88 % in 15 min with a mineralization of 60.43 % when the dosage of catalyst was 0.01 g L−1. Capture experiments and EPR tests showed that SO4−•, •OH, •O2− and 1O2 were jointly participated in the levofloxacin degradation process. Meanwhile, the BC@CobC/PMS system was minimally affected by the pH, co-existing inorganic anions, and natural active substances. It is worth noting that the BC@CobC/PMS system also had excellent removal effect on other typical organic pollutants, and the removal rate could reach 100 %. Cycling experiments showed that BC@CobC maintained high catalytic activity after multiple recycling. The degradation pathway of levofloxacin was also analyzed. Compared to the existing reports, the catalyst is economically superior, with much improved pollutant removal, and boasts a lower catalyst usage. This work will provide a viable idea in terms of reusing biomass waste and activating PMS for wastewater treatment.

Magnetic and pH dual responsive injectable magnetic zeolitic imidazole framework based colloidal gel for interventional treatment on hepatocellular carcinoma

Thermal ablation is frequently combined with systemic chemotherapy for treating hepatocellular carcinoma (HCC). However, the side effects of systemic chemotherapy on normal tissues limit its clinical application. Herein, we report a magnetic and pH dual-responsive colloidal gel assembled by doxorubicin (DOX)-loaded magnetic ZIF-8 and gelatin nanoparticles for HCC. The magnetic colloidal gel shows improved injectability and high functional particle loading, which could be injected through a 27G needle with an injection force as low as 8.8 N at 150 mg/mL solid content. Meanwhile, this colloidal gel could be magnetically heated and accelerated release DOX under tumor microenvironment, which presents a synergistic therapeutic effect by combining magnetic hyperthermia and localized chemotherapy. Furthermore, this colloidal gel could be manually injected interventional under ultrasound-guidance, exhibiting effective deep tumor treatment effect. Due to the high solid content, suitable injectability, and mechanical properties, the colloidal gel is also a promising embolic agent for transarterial embolization in HCC treatment.

Dual-Targeted Zeolitic Imidazolate Frameworks Drug Delivery System Reversing Cisplatin Resistance to Treat Resistant Ovarian Cancer.

Ovarian cancer cells are prone to acquire tolerance to chemotherapeutic agents, which seriously affects clinical outcomes. The development of novel strategies to enhance the targeting of chemotherapeutic agents to overcome drug resistance and minimize side effects is significant for improving the clinical outcomes of ovarian cancer patients. We employed folic acid (FA)-modified ZIF-90 nanomaterials (FA-ZIF-90) to deliver the chemotherapeutic drug, cisplatin (DDP), via dual targeting to improve its targeting to circumvent cisplatin resistance in ovarian cancer cells, especially by targeting mitochondria. FA-ZIF-90/DDP could rapidly release DDP in response to dual stimulation of acidity and ATP in tumor cells. FA-ZIF-90/DDP showed good blood compatibility. It was efficiently taken up by human ovarian cancer cisplatin-resistant cells A2780/DDP and aggregated in the mitochondrial region. FA-ZIF-90/DDP significantly inhibited the mitochondrial activity and metastatic ability of A2780/DDP cells. In addition, it effectively induced apoptosis in A2780/DDP cells and overcame cisplatin resistance. In vivo experiments showed that FA-ZIF-90/DDP increased the accumulation of DDP in tumor tissues and significantly inhibited tumor growth. FA-modified ZIF-90 nanocarriers can improve the tumor targeting and anti-tumor effects of chemotherapeutic drugs, reduce toxic side effects, and are expected to be a novel therapeutic strategy to reverse drug resistance in ovarian cancer.

Formulation of silver-loaded zeolitic imidazole framework-67 and its antibacterial coating on titanium surface for bioimplant applications

Artificial bioimplant infections caused by bacteria have been a persistent problem that requires re-surgery and is harmful to human tissue. A facile, inexpensive and stable antibacterial agent coating can be a significant alternative. The present study attempted to construct titanium (Ti) implant coated with silver loaded zeolitic imidazole framework (ZIF)-67 (Ag@ZIF-67)-chitosan composite through a casting technique. The as-prepared nanocomposite and its coating were subjected to various characterization techniques, including XPS, XRD, SEM, and TEM to understand the material properties. Antibacterial activity was assessed through a standard spread-plate method, and the cytocompatibility of the fabricated materials was examined upon the skin fibroblast (L929) cell line. Corrosion studies were performed by using anodic polarization and impedance methods. The bactericidal efficacy of the coating was validated in vivo by utilizing a subcutaneous mouse model. The nanocomposite and coating exhibited a significant antibacterial efficiency of above 95 % against S. aureus and E. coli as the combined release of Co2+ and Ag+ ions entailed cellular membrane disintegration. The Ag@ZIF-67 composite revealed negligible cytotoxicity and its coating exhibited strong bone cell attachment. In contrast to pure Ti surface, the Ag@ZIF-67-chitosan coated Ti exhibited a minor reduction in corrosion resistance and modifications to its passivation properties as a result of the formation of a galvanic cell. A remarkable antibacterial effect was evinced through the in vivo experiments demonstrating a complete disinfection with 99 % of S. aureus lysis with no bacterial growth in the nearby healthy tissues. In conclusion, the current results demonstrated that the fabricated Ag@ZIF-67 could be applied as an antibacterial coating material of Ti for bioimplant applications.

Metal-organic framework and MXene (ZIF-8:Ti3C2Tx) based organic and inorganic nanocomposite for bio-synaptic applications

Organic and inorganic hybrid materials have drawn more interest in the field of electronic devices. The metal-organic frameworks (MOFs) have emerged as one of the promising hybrid materials for electronic devices. However, their limited electrical conductivity hinders their electronic applications. To overcome these shortcomings, we synthesized MOF:MXene nanocomposite to enhance the stability and electrical conductivity of MOF. In particular, we synthesized and characterized zeolitic imidazolate framework-8 (ZIF-8):MXene (Ti3C2Tx) hybrid nanocomposite. From the application point of view, we demonstrated the analog memory effect and mimicked various synaptic learning functionalities using Ag/ZIF-8:Ti3C2Tx/FTO resistive switching (RS) device. The fabricated device exhibits a good analog-type bipolar RS effect. The device mimics various bio-synaptic properties such as potentiation, depression, excitatory-post synaptic current, and paired-pulse facilitation (PPF) index (%). The inherent non-ideal memristor property was dominated in the device, owing to the double-valued charge-flux relation. The conduction and possible RS mechanisms of the Ag/ZIF-8:Ti3C2Tx/FTO device were reported. These results suggested that the ZIF-8:Ti3C2Tx nanocomposite is a potential nanomaterial for brain-inspired computing applications.

Synergistic Enhancement of Electron Dynamics and Optical Properties in Zeolitic Imidazolate Framework-8-Derived Zinc Oxide via Surface Plasmon Resonance Effects of Silver Nanoparticles under UV Irradiation.

This study investigates the surface plasmon resonance (SPR)-induced UV photoresponse of zinc oxide (ZnO) derived from zeolitic imidazolate framework-8 (ZIF-8) to assess the influence of silver nanoparticles (Ag NPs) on the photoresponse behavior of metal-organic framework (MOF)-derived ZnO. The initial synthesis involved a thermal treatment in air to convert ZIF-8 into ZnO. We noted enhanced optical absorption both in the UV and visible spectra with the deposition of Ag NPs onto the ZIF-8-derived ZnO. Additionally, the presence of Ag NPs in the ZnO resulted in a substantial increase in current, even without any light exposure. This increase is attributed to the transfer of electrons from the Ag NPs to the ZnO. Photocurrent measurements under UV illumination revealed that the photocurrent with Ag NPs was significantly higher-by two orders of magnitude-compared with that without Ag NPs. This demonstrates that SPR-induced absorption markedly boosted the photocurrent, although the current rise and decay time constants remained comparable to those observed with ZnO alone. Although Ag NPs contribute electrons to ZnO, creating a "pre-doping" effect that heightens baseline conductivity (even in the absence of light), this does not necessarily alter the recombination dynamics of the photogenerated carriers, as indicated by the similar rise and decay time constants. The electron transfer from Ag to ZnO increases the density of charge carriers but does not significantly influence their recombination.