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The integration of functional nanomaterials with tissue engineering scaffolds has emerged as a promising solution for simultaneously treating malignant bone tumors and repairing resected bone defects. However, achieving a uniform bioactive interface on 3D-printing polymer scaffolds with minimized microstructural heterogeneity remains a challenge. In this study, we report a facile metal-coordination self-assembly strategy for the surface engineering of 3D-printed polycaprolactone (PCL) scaffolds with nanostructured two-dimensional conjugated metal-organic frameworks (cMOFs) consisting of Cu ions and 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP). A tunable thickness of Cu-HHTP cMOF on PCL scaffolds was achieved via the alternative deposition of metal ions and HHTP. The resulting composite PCL@Cu-HHTP scaffolds not only demonstrated potent photothermal conversion capability for efficient OS ablation but also promoted the bone repair process by virtue of their cell-friendly hydrophilic interfaces. Therefore, the cMOF-engineered dual-functional 3D-printing scaffolds show promising potential for treating bone tumors by offering sequential anti-tumor effects and bone regeneration capabilities. This work also presents a new avenue for the interface engineering of bioactive scaffolds to meet multifaceted demands in osteosarcoma-related bone defects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The excessive and prolonged use of antibiotics contributes to the emergence of drug-resistant S. aureus strains and potential dysbacteriosis-related diseases, necessitating the exploration of alternative therapeutic approaches. Herein, we present a light-activated nanocatalyst for synthesizing in situ antimicrobials through photoredox-catalytic click reaction, achieving precise, site-directed elimination of S. aureus skin infections. Methylene blue (MB), a commercially available photosensitizer, was encapsulated within the Cu II -based metal-organic framework, MOF-199, and further enveloped with Pluronic F-127 to create the light-responsive nanocatalyst MB@PMOF. Upon exposure to red light, MB participates in a photoredox-catalytic cycle, driven by the 1,3,5-benzenetricarboxylic carboxylate salts (BTC - ) ligand presented in the structure of MOF-199. This light-activated MB then catalyzes the reduction of Cu II to Cu I through a single-electron transfer (SET) process, efficiently initiating the click reaction to form active antimicrobial agents under physiological conditions. Both in vitro and in vivo results demonstrated the effectiveness of MB@PMOF-catalyzed drug synthesis in inhibiting S. aureus, including their methicillin-resistant strains, thereby accelerating skin healing in severe bacterial infections. This study introduces a novel design paradigm for controlled, on-site drug synthesis, offering a promising alternative to realize precise treatment of bacterial infections without undesirable side effects., (© 2024 Wiley-VCH GmbH.)

Chemodynamic therapy (CDT) can induce cancer cell death through hydroxyl radicals (·OH) generated from Fenton or Fenton-like reactions. Compared with traditional therapies, CDT effectively overcomes inevitable drug resistance and exhibits low side effects. However, clinical application still faces challenges, primarily due to insufficient ·OH generation and the short-lifetime of ·OH in vivo. To address these challenges, we developed a peroxynitrite (ONOO - )-based CDT nanodrug (DOX@PMOF) composed of MOF-199, NO donor (PArg), and nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) activator (doxorubicin, DOX). In DOX@PMOF, MOF-199 serves as both a carrier for loading DOX and a source of Cu + for triggering CDT. Upon uptake by cancer cells, the high concentration of glutathione (GSH) reduces MOF-199 to Cu + , which then reacts with H 2 O 2 to generate ·OH. Moreover, the released DOX upregulates NOX4 expression, leading to the elevated H 2 O 2 level and thereby promoting a high-efficiency Fenton-like reaction for sufficient ·OH generation. Subsequently, PArg generates abundant NO in response to the tumor microenvironment, leading to a cascade of NO and ·OH for the in situ synthesis of ONOO - . ONOO - is more toxic and has a longer lifetime and diffusion distance than ·OH, resulting in a more effective CDT treatment. To further enhance the in vivo therapeutic effect, we coated DOX@PMOF with a homologous cell membrane to form an active tumor-targeting nanodrug (DOX@MPMOF), which has demonstrated the ability to effectively inhibit tumor growth and metastasis while exhibiting good biosafety.

A novel Gd-MOF based on tetrafluoro-terephthalic acid has been synthesized and its structure has been solved using X-ray single crystal diffraction data. The compound, with the formula [Gd 2 (F 4 BDC) 3 ·H 2 O]·DMF, is isostructural with other Ln-MOFs based on the same ligand and has been recently reported. Its crystals were also reduced to nanometer size by employing acetic acid or cetyltrimethylammonium bromide (CTAB) as a modulator. The relaxometric properties of the nanoparticles were evaluated in solution by measuring 1 H T 1 and T 2 as a function of the applied magnetic field and temperature. The biocompatibility of Gd-MOFs was evaluated on murine microglial BV-2 and human glioblastoma U251 cell lines. In both cell lines, Gd-MOFs do not modify the cell cycle profile or the activation levels of ERK1/2 and Akt, which are protein-serine/threonine kinases that participate in many signal transduction pathways. These pathways are fundamental in the regulation of a large variety of processes such as cell migration, cell cycle progression, differentiation, cell survival, metabolism, transcription, tumour progression and others. These data indicate that Gd-MOF nanoparticles exhibit high biocompatibility, making them potentially valuable for diagnostic and biomedical applications.

Zinc metal-organic frameworks have emerged as promising candidates, demonstrating excellent biological properties stemming from the unique characteristics of MOFs and zinc. In this study, we employed a facile method to synthesize a zinc metal-organic framework [Zn(IP)(H 2 O)] using ultrasound irradiation, with the linker being isophthalic acid (IPA) (1,3-benzene dicarboxylic acid). The parent Zn-MOF and two Ag/Zn-MOF samples prepared via loading and encapsulation methods were comprehensively characterized using various techniques, including FT-IR, XRD, SEM, TEM, N 2 adsorption-desorption isotherm, UV-vis spectroscopy and TGA. The parent Zn-MOF and two Ag/Zn-MOF samples exhibited a broad spectrum of antibacterial effects. Remarkably, genomic DNA of P. aeruginosa was effectively degraded by Zn-MOF, further supporting its potent antibacterial results. The free radical inhibition assay demonstrated a 71.0% inhibition under the influence of Zn-MOF. In vitro cytotoxicity activity of Zn-MOF against HepG-2 and Caco-2 cell lines revealed differential cytotoxic effects, with higher cytotoxicity against Caco-2 as explored from the IC 50 values. This cytotoxicity was supported by the high binding affinity of Zn-MOF to CT-DNA. Importantly, the non-toxic property of Zn-MOF was confirmed through its lack of cytotoxic effects against normal lung cell (Wi-38). The anti-inflammatory treatment of Zn-MOF achieved 75.0% efficiency relative to the standard Ibuprofen drug. DFT and docking provided insights into the geometric stability of Zn-MOF and its interaction with active amino acids within selected proteins associated with the investigated diseases. Finally, the synthesized Zn-MOF shows promise for applications in cancer treatment, chemoprevention, and particularly antibacterial purposes., (© 2024. The Author(s).)

Separation of racemic drugs is of great importance and interest in chemistry and pharmacology. Here, we report the bottom-up synthesis of the binaphthyl-based chiral covalent organic frameworks (CCOFs), (R)-BHTP-COF. Then, high-performance liquid chromatography (HPLC) columns were prepared using (R)-BHTP-COF as a chiral stationary phase (CSP). Racemic ibuprofen was successfully baseline-separated on (R)-BHTP-COF-based CSP, and achieved excellent selectivity ( α = 2.32) and chromatographic resolution ( R s = 3.39) factors. Meanwhile, the separation of six racemic drugs by the (R)-BHTP-COF-packed column exhibited high resolution, selectivity, and durability. The successful applications indicate the great potential of CCOFs as a novel stationary phase for efficient HPLC separation.

Photothermal therapy (PTT) and photodynamic therapy (PDT) provide targeted approaches to cancer treatment, but each therapy has inherent limitations such as insufficient tissue penetration, uneven heat distribution, extreme hypoxia, and overexpressed HSP90 in tumor cells. To address these issues, herein, by encapsulating the IR780 dye and glucose oxidase (GOx) enzyme within ZIF-8 nanoparticles, we created a versatile system capable of combining photodynamic and enhanced photothermal therapy. The integration of the IR780 dye facilitated the generation of reactive oxygen species and hyperthermia upon light activation, enabling dual-mode cancer cell ablation. Moreover, GOx catalyzes the decomposition of glucose into gluconic acid and hydrogen peroxide, leading to the inhibition of ATP production and downregulation of heat shock protein 90 (HSP90) expression, sensitizing cancer cells to heat-induced cytotoxicity. This synergistic combination resulted in significantly improved therapeutic outcomes. Both in vitro and in vivo results validated that the nanoplatform demonstrated superior specificity and favorable therapeutic responses. Our innovative approach represents a promising strategy for overcoming current limitations in cancer treatments and offers the potential for clinical translation in the future.

Carbonic anhydrase (CA) plays a crucial role in the CO 2 capture processes by catalyzing the hydration of CO 2 . In this study, we synthesized a bioinspired carbonic anhydrase Zn-MOF (metal-organic framework) incorporating 2-aminoimidazole and Zn 2+ as initial constituents. The synthesized Zn-MOF exhibited promising potential for efficiently catalyzing the CO 2 hydration. Structural analyses such as SEM, XRD, and BET confirmed that the Zn-MOF crystal consisted of stacked grains with an average size of approximately 36 nm, forming a micron-sized spherical structure. Functionally, Zn-MOF exhibited effective catalytic activity toward both CO 2 hydration and ester hydrolysis. The introduction of amino groups significantly enhanced the esterase activity of Zn-MOF to 0.28 U/mg at ambient temperature, which was twice that of ZIF-8. Furthermore, the introduction of amino groups resulted in remarkable hydrothermal stability, with the esterase activity reaching 0.72 U/mg after undergoing hydrothermal treatment at 80 °C for 12 h. Additionally, Zn-MOF exhibited enhanced capability in CO 2 hydration at a pH value exceeding 8.5. After six repeated uses, ZIF-8 and Zn-MOF retained approximately 68 and 65% of their initial enzyme activity, respectively, underscoring the potential practical applicability of Zn-MOF in industrial CO 2 capture processes. This work showcases the development of a novel Zn-MOF crystal as an efficient CA mimic, effectively emulating the active sites of natural CA using 2-aminoimidazole as a coordinating ligand for Zn 2+ coordination. These findings not only advance the field of innovative enzyme mimics but also pave the way for further exploration of industrial CO 2 capture catalysts.

The synthesis of bioinspired metal-organic frameworks (MOFs) performed in mild conditions with a high quality is greatly demanded. Moreover, the influence of the morphology and structure of bio-MOFs on the cell interaction and toxicity is important to determine. In this work, we developed an ultrasound (US)-assisted synthesis of HKUST-1 MOFs under mild conditions and investigated the influence of the parameters of synthesis on the morphology, structure, and biological properties of the developed MOFs. It was found that the US power, reaction time, temperature, and type of solvent composition would affect the morphology, size, and yield of the obtained crystals. Employing the optimal synthetic conditions, five types of HKUST-1 MOFs were prepared, achieving highest yields (67.8-96.2%) and different morphologies (octahedral, dodecahedral, icosahedral). The relationship between the morphological features and biological properties of developed bio-MOFs was evaluated and discussed. The cellular association and cytotoxicity of MOF@US and MOF@US-PARG were studied on various cell cultures, i.e. normal mouse embryonic fibroblasts (MEF NF2), chronic myeloid leukemia (K562), and mouse melanoma (B16-F10). The experimental results showed that MOF@US-PARG has a higher percentage of association compared to MOF@US. It has also been shown that the cytotoxicity depends on the concentration and surface modification of the developed MOFs.

In the past few decades, scaffolds manufactured from composite or hybrid biomaterials of natural or synthetic origin have made great strides in enhancing wound healing and repairing fractures and pathological bone loss. However, the prevailing use of such scaffolds in tissue engineering is accompanied by numerous constraints, including low mechanical stability, poor biological activity, and impaired cell proliferation and differentiation. The performance of scaffolds in wound and bone tissue engineering may be enhanced by some modifications in the synthesis of nanoscale metal-organic framework (nano-MOF) scaffolds. Nano-MOFs have attracted researchers' attention in recent years due to their distinctive features, which include tenability, biocompatibility, good mechanical stability, and ultrahigh surface area. The biological properties of scaffolds are enhanced and tissue regeneration is facilitated by the introduction of nano-MOFs. Moreover, the physicochemical characteristics, drug loading, and ion release capacities of the scaffolds are improved by the nanoscale structure and topological features of nano-MOFs, which also control stem cell differentiation, proliferation, and attachment. This review provides further comprehensive detail about the most recent uses of nano-MOFs in tissue engineering. The distinct characteristics of nano-MOFs are explored in enhancing tissue repair, wound healing, osteoinduction, and bone conductivity. Significant attributes include high antibacterial activity, substantial drug-loading capacity, and the ability to regulate drug release. Finally, this discussion addresses the obstacles, clinical impediments, and considerations encountered in the application of these nanomaterials to diverse scaffolds, tissue-mimicking structures, dressings, fillers, and implants for bone tissue repair and wound healing.

The ground-breaking combination of photodynamic therapy (PDT) and photothermal therapy (PTT) has attracted much attention in medical fields as an effective method for fighting cancer. However, evidence suggests that the therapy efficiency is still limited by shallow light penetration depth and poor photosensitizer loading capacity. Herein, we constructed an upconversion nanoparticle@Zr-based metal-organic framework@indocyanine green molecule (UCNPs@ZrMOF@ICG) nanocomposite to integrate 1532 nm light-triggered PDT and 808 nm light-mediated PTT. NaLnF 4 nanoparticles are designed to emit upconversion luminescence (UCL) under 1532 nm laser excitation, which is consistent with the absorption spectra of the ZrMOF. Benefiting from the excellent energy transfer efficiency, the ZrMOF can absorb visible light from the UCNPs and then catalyze O 2 into 1 O 2 for deep tissue PDT. To achieve combination therapy, the clinically approved ICG nanocomposite was introduced as a photothermal agent for PTT under 808 nm laser irradiation, and the photothermal conversion efficiency was calculated to be ∼28%. The designed nanosystems facilitate efficient deep-tissue tumor treatment by integrating PDT with PTT. Ultimately, this study creates a multifunctional nanocomposite by combining 1532 nm light-triggered deep tissue PDT and near-infrared (NIR) light-driven PTT for personalized cancer therapy.

In recent years, metal-organic frameworks (MOFs) have garnered widespread attention due to their distinctive attributes, such as high surface area, tunable properties, biodegradability, extremely low density, high loading capacity, diverse chemical functionalities, thermal stability, well-defined pore sizes, and molecular dimensions. Increasingly, biomedical researchers have turned their focus towards their multifaceted development. Among these, stimuli-responsive MOFs, with their unique advantages, have captured greater interest from researchers. This review will delve into the merits and drawbacks of both endogenous and exogenous stimuli-responsive MOFs, along with their application directions. Furthermore, it will outline the characteristics of different synthesis routes of MOFs, exploring various design schemes and modification strategies and their impacts on the properties of MOF products, as well as how to control them. Additionally, we will survey different types of stimuli-responsive MOFs, discussing the significance of various MOF products reported in biomedical applications. We will categorically summarize different strategies such as anticancer therapy, antibacterial treatment, tissue repair, and biomedical imaging, as well as insights into the development of novel MOFs nanomaterials in the future. Finally, this review will conclude by summarizing the challenges in the development of stimuli-responsive MOFs in the field of biomedicine and providing prospects for future research endeavors.

Morphological modulation in covalent organic frameworks (COFs) with particular emphasis on the correlation between structure and target applications in biomedical fields, is currently in its early stage of evolution. Herein, a multifunctional rattle-architecture imine-based COF with a mobile core of gold nanoparticles (Au NPs) and an outer polydopamine (PDA) shell, tailored for cancer treatment, has been developed to effectively integrate dual responsive release capabilities with the potential for multiple therapeutic applications. The engineered COF displays outstanding crystallinity, a suitable size and precisely controlled morphological characteristics. By leveraging COF and PDA attributes, the successful co-delivery of hydrophilic doxorubicin (DOX) and hydrophobic docetaxel (DTX) within discrete compartments is achieved responsive to both pH and near-infrared triggers. Designed nanocarrier outperforms prior COFs with a superior 83.7% DOX loading capacity, thanks to its expansive internal space and porous shell. Taking advantage of the inclusion of Au core and the concurrent presence of COF and PDA outer shells, the nanocarrier exhibits a significant photothermal-conversion capability. The rattle-architecture double-shelled Au@RCOF@PDA were functionalized with poly(ethylene glycol)-folic acid (PEG-FA) to confer the system with active-targeting capability and enhanced biocompatibility. Through in vitro and in vivo evaluations, the designed system demonstrates an exceptional synergistic anti-tumor effect, along with favorable biosafety and histocompatibility. This study not only sheds light on the remarkable merits offered by regulating the morphology of COF-based systems in cancer therapy but also highlights the potential for synergistic therapeutic approaches in advancing cancer treatment strategies.

Gossypol (Gsp) and antibiotics present in water bodies become organic pollutants that are harmful to human health and the ecological environment. Accurate and effective detection of these pollutants has far-reaching significance in many fields. A new three-dimensional metal-organic framework (MOF), {[Eu 3 (L) 2 (HCOO - )(H 2 O) 3 ]·2H 2 O·2DMF} n ( Eu-MOF ), was synthesized from 3,5-bis(2,4-dicarboxylphenyl)nitrobenzene (H 4 L) ligand and Eu 3+ via the solvothermal method in this paper. The Eu-MOF demonstrates strong red fluorescence and can remain stable in different pH solutions. The MOF fluorescence probe could detect organic pollutants through the "shut-off" effect, with a fast response speed and a low detection limit [Gsp, nitrofurantoin (NFT), and nitrofurazone (NFZ) for 0.43, 0.38, and 0.41 μM, respectively]. During the testing process, Eu-MOF exhibited good selectivity and recoverability. Furthermore, the mechanism of fluorescence quenching was investigated, and the recoveries were also good in real samples. This paper introduced a deep learning model to recognize the fluorescence images, a portable intelligent logic detector designed for real-time detection of Gsp by logic gate strategy, and an anticounterfeiting mark prepared based on inkjet printing. Importantly, this work provides a new way of thinking for the detection of organic pollutants in water with high sensitivity and practicality by combining the fluorescence probe with machine learning and logical judgment.

Although hierarchically porous zeolitic imidazolate frameworks (HPZIFs) not only inherit the intrinsic architectural and chemical stabilities of their microporous counterparts but also afford open space for the efficient mass diffusion of the macromolecules involved, their rational design and construction are still challenging. Herein, HPZIFs with tailorable pore sizes ranging from 18 to 54 nm were successfully fabricated by using a newly developed soft-template-directed strategy. Our success rooted in the fact that the screened PS 81 -PVP 44 -PEO 113 triblock copolymer could effectively coordinate with the metal precursor for the directed crystallization of ZIFs along surfactant assemblies. The advantages of continuous large pores and open structures in such HPZIFs were fully taken into account to serve as a bioreactor for the efficient immunoassay. The expanded large pores provided not only a significantly vast surface area to enhance the density of capture antibodies but also enough space for accommodating multiple conjugated biomolecules in one pore channel. In combination with a cascade enzyme cycle amplification strategy, a model biomarker of prostate-specific antigen (PSA) at the femtomolar level was checked with a limit of detection of 92 fM using the developed immunosensor. Specific screening on patients with prostate cancer or even benign prostatic hyperplasia was exemplified through accurately quantifying small changes of PSA concentration in clinical serum samples, prefiguring the great potential of the developed HPZIF-8 immunosensor platform for the early monitoring and diagnostics of diseases.

Cyclodextrin-based metal-organic frameworks (CD-MOFs) are gaining traction in the realm of drug delivery due to their inherent versatility and potential to amplify drug efficacy, specificity, and safety. This article explores the predominant preparation techniques for CD-MOFs, encompassing methods like vapor diffusion, microwave-assisted, and ultrasound hydrothermal approaches. Native CD-MOFs present compelling advantages in drug delivery applications. They can enhance drug loading capacity, stability, solubility, and bioavailability by engaging in diverse interactions with drugs, including host-guest, hydrogen bonding, and electrostatic interactions. Beyond their inherent properties, CD-MOFs can be customized as drug carriers through two primary strategies: co-crystallization with functional components and surface post-modifications. These tailored modifications pave the way for controlled release manners. They allow for slow and sustained drug release, as well as responsive releases triggered by various factors such as pH levels, glutathione concentrations, or specific cations. Furthermore, CD-MOFs facilitate targeted delivery strategies, like pulmonary or laryngeal delivery, enhancing drug delivery precision. Overall, the adaptability and modifiability of CD-MOFs underscore their potential as a versatile platform for drug delivery, presenting tailored solutions that cater to diverse biomedical and industrial needs., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work. There is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled., (Copyright © 2024. Published by Elsevier Masson SAS.)

The selective separation and purification of artesunate (ARU) and artemisinin (ART) using zirconium-based metal-organic frameworks (MOF), especially UiO-66 MOF, are receiving increasing attention. In this study, tunable "hydrophobic" sites of thiol (-SH) were introduced to amino-functionalized MOFs (UiO-66-NH 2 ) to fabricate a thiol-amino bifunctional UiO-66/polyvinylidene fluoride (PVDF)-blended membrane (S1-UiO/PVDF-DPIM) via the delayed-phase-inversion method for selective separation of ARU/ART. The adsorption results indicated that the modification of UiO-66-NH 2 with thiol can indeed increase the ARU adsorption. The thiol-functional MOF (S1-UiO-66-NH 2 ) was chosen as the optimal thiol-amino bifunctional MOF, as it possessed the maximum ARU adsorption capacity (111.14 mg g -1 ) and the highest selective-separation factor (α = 51.84). The ATR FT-IR dynamic spectrum disclosed the recognition mechanism, indicating that incorporating thiol groups into a hydrophilic MOF as hydrophobic sites can boost adsorption efficiency. Moreover, the static-selective permeation results showed that the S1-UiO/PVDF-DPIM preferentially transfers ARU when mixed with ART, even achieving complete ARU/ART separation. The most crucial aspect was the introduction of a hydrophobic core of -SH and new spontaneously formed disulfide bonds to S1-UiO/PVDF-DPIM, creating alternated hydrogen bonds and hydrophobic interactions. This work provides an alternative strategy to prepare hydrophobic-hydrophilic MOF-based membranes for the highly efficient and selective separation of complex analogue systems.

A new quinoline-based COF (covalent organic framework), obtained by Povarov reaction, containing 2,6-diisopropylphenyl moieties as substituents over the heterocyclic ring is described for detecting Zn 2+ in aqueous solution. The introduction of the mentioned bulky phenyl rings into the network favors an increase of the distance between the reticular sheets and their arrangement, obtaining a new material with an alternating AB type stacking. The new material exhibits good selectivity to detect Zn 2+ by fluorescence emission in aqueous solutions up to a concentration of 1.2 × 10 -4  m of the metal ion. In order to have a deeper insight into the interaction between the COF and the zinc cation, a thorough spectroscopical, microscopical, and theoretical study is also presented and discussed in this communication., (© 2024 The Authors. Macromolecular Rapid Communications published by Wiley‐VCH GmbH.)

Reactive oxygen species (ROS)-driven chemodynamic therapy has emerged as a promising anti-tumor strategy. However, the insufficient hydrogen peroxide (H 2 O 2 ) supply in tumor microenvironment results in a low Fenton reaction rate and subsequently poor ROS production and therapeutic efficacy. Herein, we report on a new nanocomposite MIL-53@ZIF-67/S loaded with doxorubicin and glucose oxidase, which is decomposed under the acidic tumor microenvironment to release Fe 3+ , Co 3+ , glucose oxidase, and doxorubicin. The released content leads to synergistic anti-tumor effect through the following manners: 1) doxorubicin is directly used for chemotherapy; 2) Fe 3+ and Co 3+ result in glutathione depletion and Fenton reaction activation through Fe 2+ and Co 2+ generation to achieve chemodynamic therapy; 3) glucose oxidase continuously catalyzes glucose consumption to induce starvation of the cancer cells, and 4) at the same time the produced gluconic acid and H 2 O 2 significantly promote Fenton reaction and further boost chemodynamic therapy. This work not only demonstrates the high anti-tumor effect of the new nanocomposite, but also provides an innovative strategy for the development of a multi-in-one nanoplatform for cancer therapy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Nitrofuran antibiotics (NFAs) residues in waterare a persistent concern for the public due to the potential threats they pose to human health and the environment. Therefore, efficient probes that are capable of detecting trace amounts of antibiotics in real water environments have become a top priority. Herein, a novel fluorescent Zn-MOF probe (MOF-1) was revealed for the highly selective and sensitive sensing of NFAs. MOF-1 was rationally constructed with Zn(NO 3 ) 2 ·6H 2 O, 5,5'-(anthracene-9,10-diyl) diisophthalic acid (H 4 ADIP) and 1,3-bis(imidazol-1-ylmethyl)-benzene (mbib) by using the solvothermal method. Fluorescence sensing experiments demonstrate that MOF-1 can function as a fluorescent sensor for selective, sensitive, and rapid detection of NFAs among 15 antibiotics including ciprofloxacin (CPFX), chloramphenicol (CAP), sulfonamides and NFAs. Fluorescence titration experiments indicated that MOF-1 exhibited remarkably low detection limits of 0.19 μM, 0.26 μM, and 0.34 μM for furazolidone (FZD), furaltadone (FDH) and nitrofurazone (NFZ), respectively. Meanwhile, MOF-1 was successfully employed for NFAs detection in real samples with the recoveries of 98.7 % - 104.1 %, and a relative standard deviation below 5.1 %. Moreover, the sensing mechanism could be ascribed to the synergistic effect between the internal filtering effect and photoinduced electron transfer according to the experiment results and DFT calculations. Additionally, test strips were prepared based on MOF-1 for point of care testing of NFAs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Abnormal homocysteine (Hcy) levels in human serum have been associated with serious or vital diseases, making the reliable and easy detection of Hcy important to clinical analysis and biological study. In this work, five phosphorescent Ir(C^N) 2 (N^N) complexes (Ir n ) having aldehyde group were synthesized as probes (C^N and N^N denoted ligands). A discussion was conducted on their molecular structure, electronic structure, photophysical parameters, and Hcy sensing ability, revealing the correlations between their molecular structures and performances. Ir n emission was enhanced (by ∼ two folds) and blue-shifted (by 100 nm) after meeting Hcy (free state), via a cyclization reaction between the -CHO group (from Ir n ) and Hcy. In addition, using RE(BTC) as a supporting material (RE = Tb and Eu), the Ir(III) probe was loaded onto a supporting material of RE(BTC) (H 3 BTC = 1, 3, 5-benzenetricarboxylic acid). The emission color was changed by increasing Hcy concentration. Straight working curves were obtained with LOD (limit of detection) of 1.9 μM and a response time of ∼200 s. The novelty of this work was the combination of Ir n with RE(BTC), which offered enhanced and blue-shifted emission upon Hcy via a cyclization reaction. This demonstrated a high level of sensitivity towards homocysteine detection., Competing Interests: Declaration of competing interest No potential conflict of interest was reported by the authors., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Photodynamic therapy (PDT) is an emerging treatment but often restricted by the availability of oxygen. Enhancing the lifespan of singlet oxygen ( 1 O 2 ) by fractionated generation is an effective approach to improve the efficacy of PDT. Herein, an imine-based nanoscale COF (TpDa-COF) has been synthesized and functionalized with a pyridone-derived structure (Py) to create a 1 O 2 -storing nanoplatform TpDa-COF@Py, which can reversibly capture and release 1 O 2 . Under 660 nm laser exposure, Py interacts with 1 O 2 produced by the porphyrin motif in COF backbones to generate 1 O 2 -enriched COF (TpDa-COF@Py + hv), followed by the release of 1 O 2 through retro-Diels-Alder reactions at physiological temperatures. The continuous producing and releasing of 1 O 2 upon laser exposure leads to an "afterglow" effect and a prolonged 1 O 2 lifespan. In vitro cytotoxicity assays demonstrates that TpDa-COF@Py + hv exhibits an extremely low half-maximal inhibitory concentration (IC 50 ) of 0.54 µg/mL on 4T1 cells. Remarkably, the Py-mediated TpDa-COF@Py nanoplatform demonstrates enhanced cell-killing capability under laser exposure, attributed to the sustained 1 O 2 cycling, compared to TpDa-COF alone. Further in vivo assessment highlights the potential of TpDa-COF@Py + hv as a promising strategy to enhance phototheronostics and achieve effective tumor regression. Accordingly, the study supplies a generalized 1 O 2 "afterglow" nanoplatform to improve the effectiveness of PDT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Anthrax bacillus is a very dangerous zoonotic pathogen that seriously endangers public health. Rapid and accurate qualitative and quantitative detection of its biomarkers, 2,6-dipicolinic acid (DPA), is crucial for the prevention and treatment of this pathogenic bacterium. In this work, a novel Cd-based MOF (TTCA-Cd) has been synthesized from a polycarboxylate ligand, [1,1':2',1″-terphenyl]-4,4',4″,5'-tetracarboxylic acid (H 4 TTCA), and further doped with Tb(III), forming a dual-emission lanthanide-functionalized MOF hybrid (TTCA-Cd@Tb). TTCA-Cd@Tb can be developed as a high-performance ratiometric fluorescent sensor toward DPA with a very low detection limit of 7.14 nM and high selectivity in a wide detection range of 0-200 μM, demonstrating a big advancement and providing a new option for the detection of DPA.

Antibiotic resistance is a significant global concern, necessitating the development of either new antibiotics or advanced delivery methods. With this in mind, we report on the synthesis and characterisation of a new family of Metal-Organic Frameworks (MOFs), OnG6 MOFs, designed to act as multi-drug carriers for bacterial infection treatment. OnG6 is based on the pro-drug 4,4'-azodisalicylic acid (AZDH 4 ), which in vivo produces two equivalents of para -aminosalicylic acid (ASA), a crucial drug for M. tuberculosis treatment. X-ray and computational studies revealed that OnG6 MOFs are mesoporous MOFs with etb topology and an [M 2 (AZD)] formula (M = Zn, OnG6-Zn; Mg, OnG6-Mg; Cu, OnG6-Cu; and Co, OnG6-Co), featuring 1-dimensional channel type pores of 25 Å diameter. OnG6 MOFs are the first reported MOFs bearing the ligand AZDH 4 , joining the family of mesoporous MOFs arranged in a honeycomb pattern. They absorb isoniazid (INH) and ciprofloxacin (CIPRO) with the former being a specific antibiotic for M. tuberculosis , and the latter being a broader-spectrum antibiotic. The stability of the MOFs and their capacity for antibiotic uptake depend on the nature of the metal ion, with OnG6-Mg demonstrating the highest drug absorption. The antimicrobial activity of these species was assessed against S. aureus and E. coli , revealing that the carriers containing CIPRO displayed optimal efficacy.

Zeolitic imidazolate framework-8 (ZIF-8) encapsulating enzymatically active biomolecules has emerged as a novel biocompatible nanozyme and offers significant implications for bioanalysis of various biomarkers towards early diagnosis of severe diseases such as cancers. However, the rapid, continuous and scalable synthesis of these nanozymes still remains challenging. In this work, we proposed a novel microfluidic approach for rapid and continuous synthesis of hemin@ZIF-8 nanozyme. By employing a distinctive combination of zigzag-shaped channel and spiral channel with sudden expansion structures, we have enhanced the mixing efficiency within the chip and achieved effective encapsulation of hemin in ZIF-8. The resulting hemin@ZIF-8 nanoparticles exhibit peroxidase-like activity and are capable of detecting free H 2 O 2 with a limit of detection (LOD) as low as 45 nM, as well as H 2 O 2 secreted by viable cells with a detection threshold of approximately 10 cells per mL. By leveraging this method, we achieved successful detection of cancer cells and effective screening of anticancer drugs that induce oxidative stress injury in cancer cells. This innovative microfluidic strategy offers a new avenue for synthesizing functional nanocomposites to facilitate the development of next-generation diagnostic tools for early disease detection and personalized medicine.

Herein, we report a composite COF material loaded with a Pt nanoenzyme and an organic photosensitizer BODIPY, synthesized via a stepwise post-synthetic modification. The obtained Pt@COF-BDP nanoparticles can efficiently and continuously convert H 2 O 2 to O 2 , thereby increasing the efficiency of single-linear oxygen production and achieving efficient tumor inhibition.

The low cost and simple detection method for Hcy (homocysteine) is highly desired in analytical and biological fields since Hcy has been regarded as a bio-marker for multiple diseases. In this work, five Ir(C^N) 2 (N^N) + compounds having -CHO group in their C^N or N^N ligand were synthesized and tried for Hcy sensing. Electron-donating groups such as -NH 2 and -CH 3 were incorporated into the C^N or N^N ligand. Their geometric structure, electronic structure, and optical parameters (with or without Hcy) were analyzed and compared carefully to explore their Hcy sensing potential. The sensing mechanism was revealed by NMR titration and theoretical simulation as a cyclization reaction between the -CHO group and Hcy. The optimal compounds, which showed increased emission quantum yield (2.5-fold) and emission blue-shift (by ∼ 100 nm) upon Hcy, were then covalently grafted into a porous host bio-MOF-1. Linear working plots were fitted, with good selectivity, LOD of 0.15 μM, and response time of 33 s. The novelty of this work was the eye-sensitive emission color change of this nanosensing platform from red (without Hcy) to green (with Hcy)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this work, a novel magnetic covalent organic framework (COF (TpPa-NH 2 ) @ Fe 3 O 4 ) was prepared via two step by simple solvent method for the extraction of anionic azo dye residues in food. The as-prepared COF (TpPa-NH 2 ) @ Fe 3 O 4 nanocomposite was characterised by scanning electron microscope, transmission electron microscope, Fourier transform-infrared spectroscopy, X-ray diffraction and vibrating sample magnetometer. Before high-performance liquid chromatography with ultraviolet detection (HPLC-UV) determination, it was used as magnetic adsorbent for magnetic solid-phase extraction (MSPE) to extract and pre-concentrate three anionic azo dyes in carbonated beverage samples. The several key extraction and desorption parameters affecting the extraction recovery rate were investigated, including extraction time, pH of the solution, amount of material, adsorption time, elution solvent, pH of elution solvent, type of elution solvent, elution volume and elution time. Under optimised conditions, this method has good linearity between 5 and 500 μg L -1 (correlation coefficient > 0.9986). The limit of detection was 2.3-3.4 μg L -1 . The recoveries of the samples were between 87.5 and 96.9%, and the relative standard deviation lower than 4.6%. The developed method has broad application prospects for the analysis of anionic azo dyes in carbonated beverages., (© 2024. The Author(s), under exclusive licence to The Japan Society for Analytical Chemistry 2024.)

Pathogenic bacteria have consistently posed a formidable challenge to human health, creating the critical need for effective antibacterial solutions. In response, enzyme-metal-organic framework (MOF) composites have emerged as a promising class of antibacterial agents. This study focuses on the development of an enzyme-MOF composite based on HZIF-8, incorporating the advantages of simple synthesis, ZIF-8 antibacterial properties, lysozyme hydrolysis, and high biological safety. Through a one-pot method, core-shell nanoparticles (HZIF-8) were synthesized. This structure enables efficient immobilization of lysozyme and lactoferrin within the HZIF-8, resulting in the formation of the lysozyme-lactoferrin@HZIF-8 (LYZ-LF@HZIF-8) composite. Upon exposure to light irradiation, HZIF-8 itself possessed antibacterial properties. Lysozyme initiated the degradation of bacterial peptidoglycan and lactoferrin synergistically enhanced the antibacterial effect of lysozyme. All of the above ultimately contributed to comprehensive antibacterial activity. Antibacterial assessments demonstrated the efficacy of the LYZ-LF@HZIF-8 composite, effectively eradicating Staphylococcus aureus at a cell density of 1.5 × 10 6 CFU/mL with a low dosage of 200 μg/mL and completely inactivating Escherichia coli at 400 μg/mL with the same cell density. The enzyme-MOF composite exhibited significant and durable antibacterial efficacy, with no apparent cytotoxicity in vitro, thereby unveiling expansive prospects for applications in the medical and food industries.

With the rapid advancement of nanotechnology, stimuli-responsive nanomaterials have emerged as a feasible choice for the designing of controlled drug delivery systems. Zeolitic imidazolates frameworks are a subclass of Metal-organic frameworks (MOFs) that are recognized by their excellent porosity, structural tunability and chemical modifications make them promising materials for loading targeted molecules and therapeutics agents. The biomedical industry uses these porous materials extensively as nano-carriers in drug delivery systems. These MOFs not only possess excellent targeted imaging ability but also cause the death of tumor cells drawing considerable attention in the current framework of anticancer drug delivery systems. In this review, the outline of stability, porosity, mechanism of encapsulation and release of anticancer drug have been reported extensively. In the end, we also discuss a brief outline of current challenges and future perspectives of ZIFs in the biomedical world., Competing Interests: Declaration of competing interest The authors declared that the work reported in this paper has no known competing financial or personal interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Metal-organic frameworks (MOFs) are porous materials with potential in biomedical applications such as sensing, drug delivery, and radiosensitization. However, how to tune the properties of the MOFs for such applications remains challenging. Herein, we synthesized two MOFs, Zr-PEB and Hf-PEB. Zr-PEB can be classified as porous interpenetrated zirconium frameworks (PIZOFs) and Hf-PEB is its analogue. We controlled their sizes while maintaining their crystal structure by employing a coordination modulation strategy. They were designed to serve as sensitizer for X-ray therapy and as potential drug carriers. Comprehensive characterizations of the MOFs' properties have been conducted, and the in vitro biological impacts have been studied. Since viability assay showed that Hf-PEB was more biocompatible compared to Zr-PEB, the cellular uptake of Hf-PEB by cells was evaluated using both fluorescence microscopy and soft X-ray tomography (SXT), and the three-dimensional structure of Hf-PEB in cells was observed. The results revealed the potential of Zr-PEB and Hf-PEB as nanomaterials for biomedical applications and demonstrated that SXT is an effective tool to assist the development of such materials.

Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. Attempts to enhance the utility of MOFs have involved the preparation of various composites, including polymer-grafted MOFs. By directly grafting polymers to the external surface of MOFs, issues of incompatibility between polymers and MOFs can be overcome. Polymer brushes grafted from the surface of MOFs can serve to stabilize the MOF while enabling particle assembly into self-assembled metal-organic framework monolayers (SAMMs) via polymer-polymer interactions. Control over the chemical composition and molecular weight of the grafted polymer can allow for tuning of the SAMM characteristics. In this work, instructions are provided on how to immobilize a chain transfer agent (CTA) onto the surface of the MOF UiO-66 (UiO = Universitetet i Oslo). The CTA serves as initiation sites for the growth of polymers. Once polymer chains are grown from the MOF surface, the formation of SAMMs is achieved through self-assembly at an air-water interface. The resulting SAMMs are characterized and shown to be freestanding by scanning electron microscopy imaging. The methods presented in this paper are expected to make the preparation of SAMMs more accessible to the research community and thereby expand their potential use as a MOF-polymer composite.

In this study, the critical importance of designing an appropriate immobilized carrier and method for free lipase to ensure exceptional biological catalytic activity and stability was emphasized. Covalent organic frameworks (COF-1) were synthesized as a novel porous carrier with an azine structure (-CN-NC-) through the condensation of hydrazine hydrate and benzene-1,3,5-tricarbaldehyde at room temperature. Simultaneously, Rhizomucor miehei lipase (RML) was immobilized within the COF-1 carrier using an in-situ aqueous phase method. Characterization of the carrier and RML@COF-1 and evaluation of the lipase properties of RML and RML@COF-1 through p-Nitrophenyl palmitate hydrolysis were conducted. Additionally, application in the synthesis of 1, 3-dioleoyl-2-palmitoylglycerol (OPO) was explored. The results showed that RML@COF-1 exhibited a high enzymatic loading of 285.4 mg/g. Under 60℃ conditions, the activity of RML@COF-1 was 2.31 times higher than that of free RML, and RML@COF-1 retained 77.25% of its original activity after 10 cycles of repeated use, indicating its excellent thermal stability and repeatability. Under the optimal conditions (10%, 1:8 PPP/OA, 45℃, 5 h), the yield of OPO reached 47.35%, showcasing the promising application prospects of the novel immobilized enzyme synthesized via in-situ aqueous phase synthesis for OPO preparation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Covalent organic frameworks (COFs) constitute a class of highly functional porous materials composed of lightweight elements interconnected by covalent bonds, characterized by structural order, high crystallinity, and large specific surface area. The integration of naturally occurring porphyrin molecules, renowned for their inherent rigidity and conjugate planarity, as building blocks in COFs has garnered significant attention. This strategic incorporation addresses the limitations associated with free-standing porphyrins, resulting in the creation of well-organized porous crystal structures with molecular-level directional arrangements. The unique optical, electrical, and biochemical properties inherent to porphyrin molecules endow these COFs with diversified applications, particularly in the realm of biology. This review comprehensively explores the synthesis and modulation strategies employed in the development of porphyrin-based COFs and delves into their multifaceted applications in biological contexts. A chronological depiction of the evolution from design to application is presented, accompanied by an analysis of the existing challenges. Furthermore, this review offers directional guidance for the structural design of porphyrin-based COFs and underscores their promising prospects in the field of biology.

Enzyme immobilization within metal-organic frameworks (MOFs) is a promising solution to avoid denaturation and thereby utilize the desirable properties of enzymes outside of their native environments. The biomimetic mineralization strategy employs biomacromolecules as nucleation agents to promote the crystallization of MOFs in water at room temperature, thus overcoming pore size limitations presented by traditional postassembly encapsulation. Most biomimetic crystallization studies reported to date have employed zeolitic imidazole frameworks (ZIFs). Herein, we expand the library of MOFs suitable for biomimetic mineralization to include zinc(II) MOFs incorporating functionalized terephthalic acid linkers and study the catalytic performance of the enzyme@MOFs. Amine functionalization of terephthalic acids is shown to accelerate the formation of crystalline MOFs enabling new enzyme@MOFs to be synthesized. The structure and morphology of the enzyme@MOFs were characterized by PXRD, FTIR, and SEM-EDX, and the catalytic potential was evaluated. Increasing the linker length while retaining the amino moiety gave rise to a family of linkers; however, MOFs generated with the 2,2'-aminoterephthalic acid linker displayed the best catalytic performance. Our data also illustrate that the pH of the reaction mixture affects the crystal structure of the MOF and that this structural transformation impacts the catalytic performance of the enzyme@MOF.

An interfacial galvanic replacement strategy to controllable synthesize palladium nanoparticles (Pd NPs)-modified NiFe MOF nanocomposite on nickel foam, which served as an efficient sensing platform for quantitative determination of dopamine (DA). Pd NPs grown in situ on the nanosheets of NiFe MOF via self-driven galvanic replacement reaction (GRR) and well uniform distribution was achieved. This method effectively reduced the aggregation of metallic nanoparticles and significantly promoted the electron transfer rate during the electrochemical process, leading to improved electrocatalytic activity for DA oxidation. Remarkably, the precisely constructed biosensor achieved a low detection limit (LOD) of 0.068 µM and recovery of 94.1% (RSD 6.7%, N = 3) for simulated real sample detection and also exhibited superior selectivity and stability. The results confirmed that the as-fabricated Pd-NiFe/NF composite electrode could realize the quantitative determination of DA and showed promising prospects in real sample biosensing., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Covalent organic frameworks (COFs) represent a new type of crystalline porous polymers that possess pre-designed skeletons, uniform nanopores, and ordered π structure. These attributes make them well-suited for the design of light-emitting materials. However, the majority of COFs exhibits poor luminescence due to aggregation-caused quenching (ACQ), resulting from the strong interaction between adjacent layers. To break the limitation, the building units with three methoxy groups on the walls are used to construct TM-OMe-EBTHz-COF, which suppresses the ACQ effects to improve light-emitting activity of COF. The TM-OMe-EBTHz-COF exhibits a notable emission of yellow-green luminescence in the solid state, with a remarkably high absolute quantum yield of 21.1%. The methoxy groups and hydrazine linkage form three coordination sites, contributing to excellent performance in metal ions sensing. The TM-OMe-EBTHz-COF demonstrates high sensitivity and selectivity to Fe 3+ ion. Importantly, the low detection limit is below 150 nanomolar, ranking it among the best-performing Fe 3+ sensor systems., (© 2024 Wiley‐VCH GmbH.)

Covalent organic frameworks (COFs) have attracted increasing research interest due to their intriguing topological structures and fascinating properties. Diverse COFs with different shapes and sizes are developed by the design of appropriate building blocks. However, the heteroporous COFs to date are still in their infancy due to the relatively limited configuration of precursors. Herein, it is ingeniously designed and synthesized a new K-shaped "two-in-one" building unit (3',6'-bis(4-(5,5-dimethyl-1,3-dixoan-2-yl)phenyl)-[1,1':2',1"-terphenyl]-4,4"-diamine, BPTD), thus realizing the construction of triangular dual microporous COF (BPTD-COF) via self-polycondensation of the K-shaped monomer. The super micropore (0.76 nm) of BPTD-COF endows the higher density of amine activity sites, while the other aperture size (1.35 nm) meets the need for accommodating cationic dyes (rhodamine B, methylene blue), thus BPTD-COF displays a distinctive selective adsorption for cationic dyes with good reusability., (© 2023 Wiley-VCH GmbH.)

The synergistic effects of photothermal therapy (PTT) and photodynamic therapy (PDT) has attracted considerable attention in the field of cancer therapy because of its excellent anti-tumor effect. This work provides a novel pH/NIR responsive therapeutic nanoplatform, IrO 2 @ZIF-8/BSA-FA (Ce6), producing a synergistic effect of PTT-PDT in the treatment of osteosarcoma. Iridium dioxide nanoparticles (IrO 2 NPs) with exceptional catalase-like activity and PTT effects were synthesized by a hydrolysis method and decorated with zeolitic imidazolate framework-8 (ZIF-8) shell layer to promote the physical absorption of Chlorin e6 (Ce6), and further functionalized with bovine serum albumin-folate acid (BSA-FA) for targeting tumor cells. The IrO 2 @ZIF-8/BSA-FA nanocomposite indicated an outstanding photothermal heating conversion efficiency of 62.1% upon laser irradiation. In addition, the Ce6 loading endows nanoplatform with the capability to induce cell apoptosis under 660 nm near-infrared (NIR) laser irradiation through a reactive oxygen species (ROS)-mediated mechanism. It was further testified that IrO 2 @ZIF-8/BSA-FA can function as a catalase and convert the endogenous hydrogen peroxide (H 2 O 2 ) into oxygen (O 2 ) to improve the local oxygen pressure under the acidic tumor microenvironment (TME), which could subsequently amplified PDT-mediated ROS cell-killing performance via relieving hypoxia microenvironment of tumor. Both in vitro and in vivo experimental results indicated that the nanomaterials were good biocompatibility, and could remarkably achieve tumor-specific and enhanced combination therapy outcomes as compared with the corresponding PTT or PDT monotherapy. Taken together, this work holds great potential to design an intelligent multifunctional therapeutic nanoplatform for cancer therapy.

Adenosine triphosphate (ATP) is an important kind of metabolized biological molecule that is formed in organisms, especially in mitochondria, is used universally as energy, and is one of the most significant multifunctional biological molecules. Metal-organic frameworks (MOFs) have been widely used in many applications such as gas storage and separation, drug delivery, heterogeneous catalysis, chemical sensors, etc. Remarkably, lanthanide MOFs (Ln-MOFs), which display large pores, multiple dimensions, and unique lanthanide luminescence properties, are widely used as chemical sensors. A novel three-dimensional probe, Eu 2 (sbdc) 3 (H 2 O) 3 (Eu-sbdc), was successfully self-assembled with Eu(NO 3 ) 3 ·6H 2 O and 5,5-dioxo-5 H -dibenzo[ b , d ]thiophene-3,7-dicarboxylic acid (H 2 sbdc). The Ln-MOF Eu-sbdc can quickly and effectively optically detect ATP via a luminescent quenching mechanism. The K sv value of Eu-sbdc is 1.02 × 10 4 M -1 , and the lower detection limit of Eu-sbdc for ATP is 20 μM, which is more sensitive to ATP. Its mechanism of monitoring ATP might be a dynamic or static quenching process. Eu-sbdc could effectively and quickly recognize ATP with high sensitivity.

H 2 O 2 detection is closely relevant to human health; however, most of the H 2 O 2 probes suffer from low accuracy and sensitivity because of the aggregating nature of solid sensors. In contrast, a mixed-matrix membrane (MMM) with high processability and flexibility is a suitable H 2 O 2 probe to overcome these drawbacks. Herein, we fabricated MOF-based MMMs by using a robust UiO-66-(COOH) 2 with carboxylate-chelating moieties, which were utilized for binding Fe (II) metal centers. The Fe (II)-immobilized MOF-MMM involved in a Fenton reaction when treated with H 2 O 2 , exhibiting a fluorescence turn-on property. Compared to the bulk-state MOF powder, the MOF-MMM sensor showed much-improved sensitivity (detection limit down to 0.0215 μM) because of the uniform dispersion of the probe and a sufficient contact with the analyte. This MOF-MMM sensor combinedly exhibited a turn-on fluorescence response and outstanding sensing properties with flexibility and processability, providing a novel platform suitable for practical sensing applications.

Chemotherapy is still an important and effective clinical treatment for cancer. However, individual drugs hardly achieve precise controlled release and targeted therapy, thus resulting in unavoidable side effects. Fortunately, the emergence of drug carriers is expected to solve the above problems. In this work, the MOF-on-MOF strategy was adopted to encapsulate DOX into double-layer NH 2 -MIL-88B to fabricate a core-shell-structured DOX@NH 2 -MIL-88B-On-NH 2 -MIL-88B (DMM) and then realize the pH and GSH dual-responsive controlled DOX release. Because of the core-shell structure, the drug-loading capacity of DMM reached 14.4 wt %, which was nearly twice that of DOX@NH 2 -MIL-88B (DM), and the controlled release performance of DMM was also improved at the same time, greatly improving the kinetics equilibrium time of DOX from 2 h (DM) to 16 h (DMM) at pH 5.0. Moreover, we found that DMM also possessed peroxidase-like catalytic activity under acidic conditions, which could catalyze H 2 O 2 to produce • OH, exhibiting the potential chemodynamical treatment of cancer. Cell experiments showed that DMM had a significant inhibitory effect against 4T1 cancer cells, and the survival rate of 4T1 cells was less than 20% at 100 ppm.

Two-dimensional covalent organic frameworks (2D-COFs) are a class of crystalline porous organic polymers that consist of covalently linked, two-dimensional sheets that can stack together through noncovalent interactions. Here we report the synthesis of a novel COF, called PyCOFamide, which has an experimentally observed pore size that is greater than 6 nm in diameter. This is among the largest pore size reported to date for a 2D-COF. PyCOFamide exhibits permanent porosity and high crystallinity as evidenced by the nitrogen adsorption, powder X-ray diffraction, and high-resolution transmission electron microscopy. We show that the pore size of PyCOFamide is large enough to accommodate fluorescent proteins such as Superfolder green fluorescent protein and mNeonGreen. This work demonstrates the utility of noncovalent structural reinforcement in 2D-COFs to produce larger and persistent pore sizes than previously possible.

Herein, we report the design of therapeutic nanoparticles by encapsulating photosensitizers and aluminum ions into metal-organic frameworks. The nanoparticles could significantly inhibit the growth of primary and rechallenged tumors by a combination of photothermal therapy and immunotherapy. This work offers a promising strategy to design an immunologic nanoplatform for "cold" tumor therapy.

Herein, we report an inorganic photothermal agent, CuS- and an organic photosensitizer, BODIPY-loaded composite nanoscale COF material via a stepwise post-synthetic modification. The obtained CuS@COF-BDP can be a dual-modal therapeutic agent to highly inhibit MCF-7 tumor cell proliferation due to its efficient singlet oxygen generation and photothermal conversion abilities.

A metal-organic polyhedron (MOP) with four paramagnetic Fe(III) centers was studied as a magnetic resonance imaging (MRI) probe. The MOP was characterized in solution by using electron paramagnetic resonance (EPR), UV-visible (UV-vis) spectroscopies, Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry, and in the solid state with single-crystal X-ray diffraction. Water proton T 1 relaxation properties were examined in solution and showed significant enhancement in the presence of human serum albumin (HSA). The r 1 relaxivities in the absence and presence of HSA were 8.7 mM -1 s -1 and 21 mM -1 s -1 , respectively, per molecule (2.2 mM -1 s -1 and 5.3 mM -1 s -1 per Fe) at 4.7 T, 37 °C. In vivo studies of the iron MOP show strong contrast enhancement of the blood pool even at a low dose of 0.025 mmol/kg with prolonged residence in vasculature and clearance through the intestinal tract of mice. The MOP binds strongly to serum albumin and shows comparable accumulation in a murine tumor model as compared to a covalently linked Gd-HSA contrast agent.

Polysaccharide/MOF composite membranes have captured the interests of many researchers during decontamination of polluted environments. Their popularity can be attributed to the relatively high chemical and thermal stabilities of these composite membranes. Chitosan is among the polysaccharides extensively used during the synthesis of hybrid membranes with MOFs. The applications of chitosan/MOF composite membranes in separation science are explored in detail in this paper. Researchers have also synthesised mixed matrix membranes of MOFs with cellulose and cyclodextrin that have proved to be effective during separation of a variety of materials. The uses of cellulose/MOF and cyclodextrin/MOF membranes for the removal of environmental pollutants are discussed in this review. In addition, the challenges associated with the use of these mixed matrix membranes are explored in this current paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs' chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality. This review summarizes the methodology for fabricating ultrasensitive and selective Zn-MOF-based sensors, as well as their application in early cancer diagnosis and therapy. This review also offers a systematic approach to understanding the development of MOFs as efficient drug carriers and provides new insights on their applications and limitations in utility with possible solutions.

Near-infrared window II (NIR-II, 1000-1700 nm) imaging displays the advantages in deep-tissue high-contrast imaging in vivo on the strength of the high temporal-spatial resolution and deeper penetration. However, the clinical utility of NIR-II imaging agents is limited by their single function. Herein, for the first time, we report the design of a multifunctional drug delivery system (DDS) assembly, CQ/Nd-MOF@HA nanohybrids, with NIR-II fluorescence (1067 nm), large Stokes shifts, and ultrahigh quantum yield, which combined targeted NIR-II luminescence bioimaging and pH-controlled drug delivery. The nanoscale metal-organic framework (MOF) as a highly promising multifunctional DDS for targeted NIR-II bioimaging and chemotherapy in vitro and in vivo lays the foundation of the MOF-based DDS for further clinical diagnosis and treatment.

Cobalt (Co) ions, which can mimic hypoxia to promote angiogenesis, exhibit great potential for bone repair. However, a key point for the use of Co ions is that their release profile should be controllable and, more importantly, suitable for the bone regeneration process. Here, 2-ethylimidazole (eIm) was introduced into zeolitic imidazolate framework-67 (ZIF-67) to slow down Co-ion release and fabricate eIm-doped ZIF-67 (eIm/ZIF-67), which was combined into gelatin methacrylate (GelMA) to obtain an in situ photo-cross-linking nanocomposite hydrogel as a tunable Co-ion controlled release system. A tunable and controlled release of Co ions from the nanocomposite hydrogel was achieved by variation of linker composition, and GelMA with 75% eIm/ZIF-67 (with 75% eIm in the precursor solutions) could maintain a 21-day sustained release of Co ions, which is matched with early-stage angiogenesis during the bone formation process. Our in vitro study also showed that the GelMA@eIm/ZIF-67 hydrogel could reduce cytotoxicity and effectively promote the angiogenic activity of human umbilical vein endothelial cells (HUVECs) and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Moreover, an in vivo rat calvarial defect model demonstrated that the GelMA@eIm/ZIF-67 hydrogel exhibited remarkably enhanced bone formation and neovascularization abilities and had good biocompatibility as shown in organ histopathological examinations. Therefore, this novel nanocomposite hydrogel has strong therapeutic potential as a desirable Co-ion controlled release system and a powerful proangiogenic/osteogenic agent for the treatment of bone defects.