Zeolitic Imidazolate Framework-8 Nanoparticles Research Articles

Modulating Fibrotic Mechanical Microenvironment for Idiopathic Pulmonary Fibrosis Therapy.

Idiopathic pulmonary fibrosis (IPF) is exacerbated by injurious mechanical forces that destabilize the pulmonary mechanical microenvironment homeostasis, leading to alveolar dysfunction and exacerbating disease severity. However, given the inherent mechanosensitivity of fibrotic lungs, where type II alveolar epithelial cells (AEC IIs) are subjected to persistent stretching and overactivated myofibroblasts experience malignant interactions during mechanotransduction, it becomes imperative to develop effective strategies to modulate the pulmonary mechanical microenvironment. Herein, cyclo (RGDfC) peptide-decorated zeolitic imidazolate framework-8 nanoparticles (named ZDFPR NPs) are constructed to target and repair the aberrant mechanical force levels in pathological lungs. Specifically, reduces mechanical tension in AEC IIs by pH-responsive ZDFPR NPs that release zinc ions and 7, 8-dihydroxyflavone to promote alveolar repair and differentiation. Meanwhile, malignant interactions between myofibroblast contractility and extracellular matrix stiffness during mechanotransduction are disrupted by the fasudil inhibition ROCK signaling pathway. The results show that ZDFPR NPs successfully restored pulmonary mechanical homeostasis and terminated the fibrosis process in bleomycin-induced fibrotic mice. This study not only presents a promising strategy for modulating pulmonary mechanical microenvironment but also pioneers a novel avenue for IPF treatment.

Targeted delivery of Saikosaponin A and doxorubicin via hyaluronic acid-modified ZIF-8 nanoparticles for TNBC treatment: Inhibiting metastasis and reducing cardiotoxicity

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the absence of estrogen receptors, progesterone receptors, and HER2 expression, making traditional hormone and targeted therapies ineffective. Chemotherapy remains the primary treatment for TNBC; however, it has failed to adequately address the high rates of recurrence and metastasis, underscoring the urgent need for new therapeutic strategies. This study investigates Saikosaponin A (SSA), a compound extracted from traditional Chinese medicine, for its potential to enhance the efficacy of doxorubicin (DOX) chemotherapy while reducing TNBC metastasis and mitigating DOX-induced cardiotoxicity.We first confirmed SSA's cardioprotective effects against DOX-induced cardiotoxicity, highlighting its potential as an adjunctive therapy for TNBC chemotherapy. Subsequently, through network pharmacology analysis, we identified that SSA may inhibit TNBC progression and metastasis by downregulating integrin β3, a key regulatory factor in tumor development. This was further validated through both in vivo and in vitro experiments. To address the poor bioavailability of SSA, we developed a novel drug delivery system utilizing hyaluronic acid (HA)-modified zeolitic imidazolate framework-8 (ZIF-8) nanoparticles for the co-delivery of SSA and DOX. This nano-drug system exhibited excellent stability and high drug-loading capacity, with loading efficiencies of 40.07 % for SSA and 43.07 % for DOX. After 24 h of nano-drug administration, the DOX concentration in the group using the nano-delivery system was 5.01 times higher than control group, demonstrated enhanced tumor-targeting capability. Furthermore, after 14 days of treatment, the tumor volume was reduced by 80.8 % compared to the control group, indicating significantly improved therapeutic efficacy (all P < 0.05).This study systematically evaluates the potential of this dual drug-loaded nanocarrier in improving TNBC treatment, reducing DOX-induced cardiotoxicity, and inhibiting metastasis, offering a novel therapeutic approach that integrates traditional medicine with advanced nanotechnology.

Just-in-Time Generation of Nanolabels via In Situ Biomineralization of ZIF-8 Enabling Ultrasensitive MicroRNA Detection on Unmodified Electrodes.

Nanolabels can enhance the detection performance of electrochemical biosensing methods, yet their practical application is hindered by complex preparation, batch-to-batch variability, and poor long-term storage stability. Herein, we present a novel electrochemical method for miRNA detection based on the just-in-time generation of zeolitic imidazolate framework-8 (ZIF-8) nanolabels initiated by nucleic acids. In this design, the target miRNA-21 is captured with magnetic beads and polyadenylated by Escherichia coli Poly(A) polymerase (EPP), producing miRNA-21 molecules with poly(A) tails (miR-21-poly(A)). These molecules are then adsorbed onto a bare gold electrode (AuE) surface via adenine-gold affinity interactions, serving as nucleation sites for the rapid in situ formation of ZIF-8 nanoparticles. The ZIF-8 nanoparticles function as signal labels, impeding electron transfer at the electrode interfaces and thereby generating a notable electrochemical signal. The developed method demonstrated exceptional sensitivity, with a detection limit (LOD) as low as 2.3 aM and a linear detection range from 10 aM to 1000 fM. The practical application of the developed method was validated by using it to evaluate miRNA-21 expression levels in various biological samples, including cell lines, tumor tissues, and clinical blood samples from non-small cell lung cancer (NSCLC) patients. This approach simplifies the detection process by eliminating the need for presynthesized nanomaterials and premodified electrodes. Its simplicity and high sensitivity make this method a promising tool for point-of-care testing and a wide range of biomedical research applications.

Synergistic bactericidal effect of antimicrobial peptides and copper sulfide-loaded zeolitic imidazolate framework-8 nanoparticles with photothermal therapy

Antimicrobial resistance (AMR) has emerged as a significant threat to human health. Antimicrobial peptides (AMPs) have proven to be an effective strategy against antibiotic-resistant bacteria, given their capacity to swiftly disrupt microorganism membranes and alter cell morphology. A common limitation, however, lies in the inherent toxicity of many AMPs and their vulnerability to protease degradation within the body. Photothermal therapy (PTT) stands out as a widely utilized approach in combating antibiotic-resistant bacterial infections, boasting high efficiency and non-invasive benefits. To enhance the stability and antibacterial efficacy of AMPs, a novel approach involving the combination of AMPs and PTT has been proposed. This study focuses on the encapsulation of At10 (an AMP designed by our group), and copper sulfide nanoparticles (CuS NPs) within zeolitic imidazolate framework-8 (ZIF-8) to form nanocomposites (At10/CuS@ZIF-8). The encapsulated CuS NPs exhibit notable photothermal properties upon exposure to near-infrared radiation. This induces the cleavage of ZIF-8, facilitating the release of At10, which effectively targets bacterial membranes to exert its antibacterial effects. Bacteria treated with At10/CuS@ZIF-8 under light radiation exhibited not only membrane folding and intracellular matrix outflow but also bacterial fracture. This synergistic antibacterial strategy, integrating the unique properties of AMPs, CuS NPs, and pH responsiveness of ZIF-8, holds promising potential for widespread application in the treatment of bacterial infections.

8-Hydroxyquinoline incorporated ZIF-8 nanocomposites for efficient decomposition and detection of manganese ions in aquatic environments

The presence of potassium permanganate in aquatic environment poses a significant issue that requires resolution. In response, zeolitic imidazolate framework nanoparticles with large pore sizes, extensive surface areas, and high chemical stability in water were synthesized. Subsequently, 8-hydroxyquinoline was incorporated into ZIF-8 (named 8-HQ@ZIF-8) to enhance its capability to decompose potassium permanganate in aquatic environment. The synthesized material underwent thorough characterization using powder X-ray diffraction, Fourier-transform infrared spectroscopy, nitrogen isothermal adsorption-desorption at 77 K, thermogravimetric analysis, and scanning electron microscopy. Electrical conductivity tests revealed that the 8-HQ@ZIF-8 material can decompose potassium permanganate within 5 min and be recycled over five runs. Furthermore, the nanocomposite of 8-HQ and ZIF-8 exhibited greater stability than the original ZIF-8 under strong oxidizing conditions. This suggests that functionalizing with organic ligands can enhance the durability and performance of the material. In addition to its degradability, the 8-HQ@ZIF-8 material, which carries manganese oxide, also displays variable fluorescence properties, making it a potential sensor for detecting residual potassium permanganate in drinking water treatment systems. Therefore, the 8-HQ@ZIF-8 material shows considerable promise for both the treatment and detection of pollutants in aquatic environments.

CFD Simulation of Chaotic Flow Characteristics in an Oscillating Feedback Microreactor and Its Application for Preparing Zeolitic Imidazolate Framework-8 Nanoparticles

CFD Simulation of Chaotic Flow Characteristics in an Oscillating Feedback Microreactor and Its Application for Preparing Zeolitic Imidazolate Framework-8 Nanoparticles

Dual-porous ZIF-8 heterogeneous catalysts with increased reaction sites for efficient PET glycolysis

Poly (ethylene terephthalate) (PET) has been widely used for drink bottles, food packing, films, and fibers, resulting in millions of tons of waste PET. Less than 10% of that waste is recycled, and the rest is discarded or incinerated. Waste PET upcycling employs chemical recycling and particularly glycolysis to create the bis(2-hydroxyethyl) terephthalate (BHET) monomer. Herein, we report a dual-porous zeolitic imidazolate framework-8 nanoparticle (DPZIF-8) heterogeneous catalyst for efficient PET glycolysis. The DPZIF-8 nanoparticles were prepared using a triethylamine modulator, which can control the nucleation and growth mechanisms of the ZIF-8 nanoparticles. The DPZIF-8 nanoparticles include both intrinsic micropores and particle-particle adhesion-induced mesopores that can provide a larger external surface area of the zinc sites in the ZIF-8 architecture. The PET glycolysis catalyzed by DPZIF-8 at 180 °C and 1 atm for 4 h shows a PET conversion of 91.7% and a BHET yield of 76.1%, the latter particularly being much higher than with a traditional heterogeneous ZIF-8 catalyst. This dual-porous structure rational design strategy can be versatile for other metal–organic frameworks (MOFs) to increase the interfacial catalytic reaction sites between the metal–organic framework and the polymer, enhancing the PET depolymerization performance and efficiency.

Immune checkpoint-regulatable hydrogel-immobilized nanotherapeutics for post-surgical treatment of osteosarcoma

Osteosarcoma recurrence following surgical resection is notoriously prevalent and resistant to chemotherapy (i.e., doxorubicin, DOX) due to its intricate immunosuppressive tumor microenvironment, which remains one of the most life-threatening tumors. In this study, we report the fabrication of an in-situ injectable hydrogel-immobilized nanotherapeutics, tailored to stimulate tumoricidal immunity, thus mitigate both localized osteosarcoma recurrence and the propagation of metastatic tumors subsequent to surgical intervention. Zeolitic imidazolate framework-8 nanoparticles (ZIF NPs), encapsulating a chemotherapeutic agent (i.e., DOX) and immunotherapeutic agents (i.e., αPDL1 and αCD47), are loaded in fibrin hydrogels. These bioengineered constructs are judiciously deployed at surgical sites to orchestrate chemo-immunotherapeutic interventions, effectuated through the controlled release of doxorubicin and the initiation of T cell-mediated immune responses. DOX has the capability to eradicate tumor cells and initiate immunogenic cell death. Notably, αPDL1 engenders the circumvention of PDL1-mediated resistance and dominates metastatic tumor expansion, thereby exerting a pivotal role in the context of systemic immunosuppression. αCD47 blocks the ‘don’t eat me’ signaling axis intrinsic to cancer cells, thereby potentiating their phagocytosis by macrophages. This orchestrated blockade synergistically activates the host immune milieu, thereby repressing tumor recurrence and curtailing the growth of metastatic lesions post-surgical resection in the subcutaneous tumor model (lateral and bilateral) and tibial tumor model (orthotopic and metastatic), respectively. Additionally, zinc ions from the degradation of ZIF NPs acts as the stimulator of interferon genes (STING) agonists to enhance the immunotherapeutic activity against distal and metastatic tumors. The reported immune checkpoint-regulatable cancer immunotherapy activates the host innate and adaptive immune systems, which shows promising for the treatment of osteosarcoma patients.

Incorporation of zeolitic imidazolate framework-8 (ZIF-8) in the polyamide and polysulfone layers of forward osmosis membranes for enhancing aquaculture wastewater recovery and PPCPs removal

Wastewater recovery is essential to alleviate water resource shortages, and this can be achieved through a high-energy-efficient forward osmosis (FO) process combined with an emerging material, zeolitic imidazolate framework-8 (ZIF-8). Here, we create thin-film composite FO membranes (TF-CFOMs) by incorporating ZIF-8 into the active polyamide (PA) and/or support polysulfone (PSf) layers to address the challenges of low water flux and loss of draw solutes during operation. Experimental factors included the dosage of ZIF-8 nanoparticles in PA preparation solutions and the dosages of 2-methylimidazole (2-Hmim) and zinc nitrate hexahydrate (ZNH) in n-methyl-2-pyrrolidone (NMP) to fabricate the PSf casting solutions with in-situ formed ZIF-8 nanoparticles. Successful ZIF-8 incorporation on the TF-CFOM surface was confirmed, and the ZIF-8 TF-CFOMs exhibited increased surface hydrophilicity and separation performance. Only modifying the PA layer by adding 0.025 wt% ZIF-8 nanoparticles in trimesoyl chloride (TMC) resulted in the membrane (PA0.025T-PSf0) with water flux 2.3 times higher than the pristine TF-CFOM (4.9 LMH). The pristine and modified TF-CFOMs were further applied for aquaculture wastewater (AWW) recovery and removal of pharmaceuticals and personal care products (PPCPs). Results of water recovery demonstrated that the recovery rate reached 89.1% in 3.5 days when using the dual-layer modified TF-CFOM. Results of PPCP removal indicated that both pristine and modified TF-CFOMs can achieve high PPCP rejection efficiency (>90%), with the modified TF-CFOM (PA0.025T-PSf2.0) performing the best. Overall, the PA0.025T-PSf2.0 TF-CFOM achieved high and stable separation efficiency in long-duration AWW recovery, making it well-suited for practical field applications.

Facile Preparation of Smart Sponge Based on a Zeolitic Imidazolate Framework for the Efficient Separation of Oily Wastewater

The fabrication of durable materials with excellent oil-adsorption capacity and separation performance for the treatment of oily wastewater is meaningful based on the special property of smart responsiveness. Herein, a solvent-responsive melamine sponge (MS) was developed via silanization and the in situ growth of a zeolitic imidazolate framework-8 (ZIF-8). Detailed characterization of the resultant composite MS was conducted using scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD). The multiscale hierarchical MS substrate exhibited highly hydrophobic properties in the pH range of 1–11, along with a satisfactory adsorption capacity in the range of 65.4–134.2 g/g for different oils. The modified surface transformed from superhydrophobic/superlipophilic to superhydrophilic/underwater superoleophobic upon ethanol wetting, reverting to its original superhydrophobic state upon drying. The separation flux of the MS substrate was above 1.5 × 104 L/m2h for both oil and water removal, and the separation efficiency was greater than 98.7%. The absence of obvious changes in separation performance after 50 successive immiscible oil−water separations indicated the excellent durability and robustness of the anchored ZIF-8 nanoparticles on the surface of the modified MS substrate. More importantly, oil-in-water emulsion separation was successfully carried out via the ZIF-8 MS composite, showing high separation efficiency (over 99.1%). The developed smart sponge, which had high oil-adsorption capacity, excellent chemical stability, and fire resistance, has a wide range of potential practical applications in the convenient treatment of oily wastewater.

ZIF-8 nanoparticles densely covered MXene as functionalized platform for electrochemical detection of medical small molecules

The high-performance electrochemical detection relies on sensing material with highly active structure, which requires the development of advanced synthesis technique and the study of its structure-activity mechanism. Herein, the few-layer Ti3C2Tx nanosheets densely coated zeolitic imidazole framework-8 nanoparticles (Ti3C2Tx@ZIF-8) have been successfully prepared as a unique precursor, which combines the structural advantages of two-dimensional Ti3C2Tx and porous ZIF-8 nanoparticles, leading to the vast interior spaces for loading electrocatalytic nanomaterials. For this purpose, Ti3C2Tx@Au nanoparticles-ZnO nanoparticles@N-doped carbon (Ti3C2Tx@AuNPs-ZnO@NC) has been obtained for the simultaneous electrochemical detection of pharmaceutical molecules including dopamine (DA), acetaminophen (AC), and xanthine (XA). The materials characterization and sensing analysis results of Ti3C2Tx@AuNPs-ZnO@NC reveal the structure-activity relationship of Ti3C2Tx, AuNPs and NC resulting in the high-performance behaviors, which can be summed up as stable electrochemical active sites and efficient electron transport channels. First, the abundant anchor points are offered by NC for immobilizing AuNPs, which ensure the electrochemical activity of such material. Second, the close combination of few-layer Ti3C2Tx nanosheets and NC provides an ideal channel for electron transmission along with the electrochemical reaction process. The potential application of Ti3C2Tx@AuNPs-ZnO@NC is displayed to develop the electrochemical medical sensor. The detection limits are 41 nM towards DA, 59 nM towards AC, and 67 nM towards XA. The linear ranges are 3–200 μM for DA, 15–500 μM for AC, and 8–350 μM for XA.

Zeolitic imidazolate framework-8 as a high-affinity adsorbent for dispersive solid-phase extraction in the analysis of plant growth regulators in fruits.

Facile and sensitive determination of plant growth regulators (PGRs) in food samples is crucial but still poses a significant challenge. In this study, to enhance the sensitivity of the HPLC-DAD method for PGR detection, a dispersive solid phase extraction (d-SPE) method using zeolitic imidazolate framework-8 (ZIF-8) as the highly effective adsorbent is developed. ZIF-8 nanoparticles are formed through the coordination of Zn2+ with 2-methylimidazole. Due to its high porosity, large surface area, abundant π electronics and nitrogen electronics, ZIF-8 exhibits a strong affinity to PGRs due to the synergistic effects of π-π interaction, van der Waals force, H-bond, and surface effect. Under the optimal d-SPE conditions, the sensitivity of the method is significantly enhanced with outstanding performances, including a wide range of linearity (2.0-200 ng g-1) with high correlation coefficients (R ≥ 0.9989), low limits of detection (LODs, 0.9-8.0 ng g-1 for all PGRs), satisfactory precision (intra-day RSDs ≤ 3.3%, inter-day RSDs ≤ 4.2%), and high accuracy (recovery: 86.6-101.5%). The developed method was successfully applied to quantitatively detect 9 PGRs in fruit samples, yielding satisfactory results. This d-SPE-HPLC-DAD method, characterized by high sensitivity, simplicity, efficiency, ease of practice and cost-effectiveness for PGR detection, shows potential for detecting PGRs in other complex samples and provides a strategy for designing target-affinity adsorbents.

Artificial Neutrophils Against Vascular Graft Infection.

Efficient neutrophil migration to infection sites plays a vital role in the body's defense against bacterial infections and natural immune responses. Neutrophils have a short lifespan and cannot be mass-cultured in vitro. Therefore, developing more stable artificial neutrophils (AN) in a controllable manner has become a research focus. However, existing AN lack chemotaxis, which is the ability to migrate toward high-signal-concentration positions in a dynamic blood- flow environment. Supplying AN with chemotaxis is key to designing AN that are more similar to natural neutrophils in terms of morphology and function. In this study, micrometer-sized, spherical, biocompatible AN are developed. These AN consist of zeolitic imidazolate framework-8 nanoparticles encapsulating two enzymes, coacervate droplet frameworks, and outer phospholipid bilayers carrying enzymes. The AN exhibit responsiveness to elevated hydrogen peroxide levels at inflammation sites, actively chemotaxing toward these sites along concentration gradients. They also demonstrate effective combat against Staphylococcus aureus infections. The capabilities of the AN are further validated through in vitro experiments and in vivo evaluations using vascular graft infection models. This study replicates natural neutrophils in terms of chemical composition, functionality, and physiological impact. It introduces new ideas for advancing the development of advanced artificial cells.

Polydopamine-armored zeolitic imidazolate framework-8-incorporated zwitterionic hydrogel with multifunctional properties for infected wound healing

Diabetic skin wound healing is compromised by bacterial infections, oxidative stress, and vascular disruption, leading to delayed recovery and potential complications. This study developed an antibacterial, antioxidant, and adhesive hydrogel dressing that promotes rapid bacterial-infected diabetic wound healing using the biological macromolecule of polydopamine (PDA). This hydrogel comprised PDA-armored zeolitic imidazolate framework-8 nanoparticles (PDA@ZIF-8 NPs) combined with a second armor of zwitterionic polymer network (poly(acrylamide-co-sulfobetaine methacrylate); PAS), realizing low concentration Zn2+ release, good adhesion (14.7 kPa for porcine skin), and improved tensile strength (83.2 kPa). The hydrogel exhibited good antibacterial efficacy against both Staphylococcus aureus (S. aureus, 92.8 %), Escherichia coli (E. coli, 99.6 %) and methicillin-resistant S. aureus (MRSA, 99.2 %), which was attributed to the properties of the incorporated PDA@ZIF-8 NPs. Notably, in vitro, the PDA@ZIF-8 PAS hydrogel not only promoted fibroblast proliferation and migration but also facilitated endothelial cell angiogenesis. In vivo, the PDA@ZIF-8 PAS hydrogel retained its Zn2+-releasing function and effectively suppressed bacterial growth in infected wounds, thereby accelerating the regeneration of both normal and diabetic wounds. This multiarmored hydrogel is a promising sustained-release carrier for functional metal ions and drugs, making it applicable for not only skin healing, but potentially the regeneration of other complex tissues.

In vitro investigation of anti-inflammatory activity of propolis/saffron extract/curcumin-loaded ZIF8 nanoparticles and their potential application for treating osteoarthritis

Abstract Background Osteoarthritis (OA) poses a significant healthcare challenge globally, necessitating the development of effective therapeutic interventions. It is crucial to develop novel drug delivery systems for OA treatment. Aims This study explores the potential of propolis, saffron extract, and curcumin-loaded zeolitic imidazolate framework-8 (ZIF8) nanoparticles as a treatment modality for OA. The anti-inflammatory and chondroprotective properties of these natural compounds make them promising candidates for OA management. Methods Through comprehensive in vitro investigations, including scanning electron microscopy (SEM), MTT assays, antiinflammatory assays, cell migration assays, Fourier transform infrared (FTIR) spectroscopy, and release assays, we evaluated the physicochemical and biological characteristics of propolis, saffron extract, and curcumin-loaded ZIF8 nanocarriers. Results Our findings demonstrate that these nanocarriers effectively encapsulated the bioactive compounds, exhibited sustained release profiles, and displayed significant anti-inflammatory properties. Notably, propolis-loaded ZIF8 nanocarriers exhibited superior anti-inflammatory activity compared to other formulations. The encapsulation of propolis, saffron extract, and curcumin within ZIF8 nanoparticles holds promise for enhancing their therapeutic efficacy and ensuring targeted delivery to affected joints in OA treatment. Conclusion This study highlights the potential of nanotechnology-based delivery systems in harnessing the therapeutic benefits of natural compounds for OA management.

Biomimetic ZIF-8 Nanoparticles: A Novel Approach for Biomimetic Drug Delivery Systems.

Metal-organic frameworks (MOFs) are porous materials resulting from the coordination of metal clusters or ions with organic ligands, merging macromolecular and coordination chemistry features. Among these, zeolitic imidazolate framework-8 (ZIF-8) stands out as a widely utilized MOF known for its robust stability in aqueous environments owing to the robust interaction between its constituent zinc ions (Zn2+) and 2-methylimidazole (2-MIM). ZIF-8 readily decomposes under acidic conditions, serving as a promising candidate for pH-responsive drug delivery systems. Moreover, biomimetic materials typically possess good biocompatibility, reducing immune reactions. By mimicking natural structures or surface features within the body, they enhance the targeting of nanoparticles, prolong their circulation time, and increase their bioavailability in vivo. This review explores the latest advancements in biomimetic ZIF-8 nanoparticles for drug delivery, elucidating the primary obstacles and future prospects in utilizing ZIF-8 for drug delivery applications.

Achieving a balance between permeability and selectivity in a ZIF-8-matrix nanocomposite membrane for desalination

Hybrid metal–organic framework (MOF)-polymer membranes are promising for addressing the permeability-selectivity tradeoff in membrane applications. The key challenges for achieving high-efficiency separation performance have been identified as increasing the MOF loading while maintaining interfacial compatibility with polymeric matrices. Herein, a novel design of ZIF-8 matrix nanocomposite membrane, with ZIF-8 nanoparticles (NPs) serving as the main matrix, was prepared by functionalizing the external surface of zeolitic imidazolate framework-8 (ZIF-8) NPs with polyethyleneimine and subsequent crosslinking into the selective layer using trimesoyl chloride as a crosslinking agent via confined interfacial polymerization. The content of ZIF-8 NPs in the selective layer was up to about 70 wt%, resulting in superior permeability (＞ 43.6 LMH bar−1) for desalination due to the large number of transport channels, which was several folds as compared to most of the reported membranes. Meanwhile, a reasonably high Na2SO4 rejection (∼95.1 %) was maintained as the polyamide fragments formed during interfacial polymerization, which filled defects among the ZIF-8 NPs. Overall, such strategy paves the way for the design of efficient MOF-based membranes for balancing between permeability and selectivity in desalination.

Surface modification of ZIF-8 nanoparticles by hyaluronic acid for enhanced targeted delivery of quercetin

Quercetin (QT) is a natural pharmaceutical substance with anti-inflammatory, antibacterial, and anti-cancer features. Nevertheless, it has low bioavailability, zeolitic-imidazolate framework-8 (ZIF-8) nanoparticles (NPs) with merits like very high surface area and porous nature are increasingly employed in the biomedical field as drug delivery system (DDS). Hyaluronic acid (HA) is a polymer that can be a smart “switch” and tumor-targeted “guider”, extending blood circulation, and improving the tumor-specific accumulation of DDS through CD44-mediated pathway. Herein, we have successfully synthesized HA-modified ZIF-8 NPs (ZIF-8/HA) for targeted delivery of QT. After characterization of synthesized materials by different advanced techniques, the QT loading capacity of ZIF-8 was investigated through different factors like initial QT concentration, solvent type, loading time and loading temperature. The release of QT in vitro was studied at pH values of 7.4 and 5.5 and ZIF-8 NPs decreased the release of QT at pH 7.4, demonstrating their ability to reduce QT loss during its distribution in blood. Also, HA-modified ZIF-8 resulted in enhanced compatibility, a decrease in toxicity to normal cells and an increase in targeted delivery of QT. Furthermore, the cytotoxicity of QT-loaded ZIF-8/HA on fibroblast cell lines (L929) as well as breast cancer cell lines (MCF-7) were evaluated. It was found that QT-loaded ZIF-8/HA not only led to a decrease in the toxicity of ZIF-8 and QT to normal cells in the body but also increased the toxicity of QT to cancer cells.

Fabrication of hydrophobic drug-loaded Zeolitic Imidazolate Framework-8 (ZIF-8) for enhanced anti-bacterial activity

Current study presents a novel approach for constructing small hydrophobic biomolecules embedded within zeolitic imidazolate framework-8 (ZIF-8) with exceptional antibacterial properties. In this method, ZIF-8 is synthesized from zinc acetate and 2-methylimidazole in the presence or absence of small hydrophobic bioactive molecules like rutin, rosmarinic acid, and morin. Scanning electron microscopy (SEM) analysis reveals that the synthesized ZIF-8 nanoparticles exhibit mostly hexagonal shape with size 200 nm which is further increased upon drug encapsulation. The synthesis of ZIF-8 and drug-loaded ZIF-8 is confirmed through FTIR, UV–vis spectroscopy, XRD, TGA, and EDX analyses. Zeta potential measurements show values ranging from -14.5 to -23.97 mV for both ZIF-8 and drug-loaded ZIF-8 nanoparticles. The drug loading content is determined to be 5 %, 9 %, and 16 % for morin, rutin, and rosmarinic acid, respectively. All the drug-loaded ZIF-8 formulations exhibit a pH-dependent drug release pattern, with maximal drug release observed at lower pH levels. Most importantly, these formulations demonstrate potent antibacterial activity against both Gram-positive (Enterococcus faecalis and Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial strains. Specifically, ZIF-8/RUT exhibit maximum zone of inhibition (ZOI ∼ 51 mm) against all tested bacterial strains. ZIF-8/MOR and ZIF-8/RUT exhibit MIC values ranging from 2.0 to 3.0 mg/mL and MBC values from 6 to 9 mg/mL against all the tested bacteria. Among the formulations, ZIF-8/MOR and ZIF-8/RUT exhibit synergistic antibacterial effect, whereas ZIF-8/RMA possess less antibacterial potency against all the tested bacteria and mostly exhibit additive effect. Our findings suggest that these newly developed nano-formulations hold potential for the creation of highly effective antibacterial agents.

Highly efficient suppression of zincate ion crossover in zinc–air batteries using selective membrane PVA-KOH/ZIF-8 gel polymer electrolytes

Rechargeable zinc–air batteries have attracted considerable attention in the industries due to their high energy density, affordability, and safety. However, these batteries still have limitations in their lifetime because of the issue of zincate ion (Zn(OH)42−) crossover. To suppress this issue, a new PVA-KOH-based gel polymer electrolyte membrane incorporating zeolitic imidazolate framework-8 (ZIF-8) nanoparticles was developed as a selective membrane. The influence of different-sized ZIF-8 nanoparticles synthesized with three different zinc salts on thermal, physical, and electrochemical properties was investigated. The PVA-KOH/ZIF-8 membrane significantly reduced the diffusion coefficient of zincate ions to 3.27 × 10−6, 2.01 × 10−6, and 1.99 × 10−6 cm2 min−1 by the incorporation of ZIF-8, synthesized with Zn(NO3)2, Zn(OAc)2, and ZnSO4, respectively. Because of the pore apertures of ZIF-8 that are equivalent to Zn(OH)42−, the PVA-KOH/ZIF-8 selective membrane could block Zn(OH)42−and allowed OH− to pass through the membrane. Moreover, a large external hydrophilic surface was achieved by the influence of smaller-sized particles, which improved the retention of electrolytes. As a result, the ionic conductivity of the PVA-KOH/ZIF-8 membrane increased up to 164.27 mS cm−1 when added 10 wt% ZIF-8, synthesized by ZnSO4. Furthermore, this membrane showed the highest value of battery life cycle of 89 cycles at a current density 10 mA cm−2 and the discharge capacity of 396 mAh g−1. These results indicated that the development of a PVA-KOH/ZIF-8 membrane has a high potential and suitability for use as a new class of separators in rechargeable zinc–air batteries.