Double Ligands Research Articles

Defective porous urchin-like ZnO/NiO microspheres-coated solid-phase microextraction fiber for analysis of trace polychlorinated biphenyls in milk.

Owing to the high lipophilicity of polychlorinated biphenyls (PCB), they easily accumulate in dairy products. Although usually present at very low levels, they pose a serious threat to human health. Therefore, developing a sensitive and reliable method for detecting PCB in dairy products is crucial. Herein, Herein, a metal-organic framework (MOF) material named with bimetallic nodes and double ligands was prepared as a precursor using a one-pot hydrothermal method. Defective porous urchin-like ZnO/NiO, derived from these MOF-based precursors (ZnNi-MOF-NH2) as a sacrificial template, was synthesized via pyrolysis to remove heat-sensitive ligands. To the best of our knowledge, this urchin-like nanostructured ZnO/NiO hybrid was utilized as a solid-phase microextraction (SPME) coating for the first time. Headspace SPME (HS-SPME) was developed for non-contact extraction of PCB in milk prior to gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. Under optimal conditions, the HS-SPME-GC-MS/MS method exhibited a wide linear range (0.01-1000ng·L-1), low limits of detection (0.003-0.025ng·L-1), and high enrichment factors (5714-9906). Additionally, the performance of the ZnO/NiO SPME fiber coating showed no noticeable decrease after 175 uses. The method was applied to trace PCB analysis in milk samples, yielding recoveries of 70.3-114.1%. The ZnO/NiO derived from MOF-based material provides a promising candidate for SPME coatings to extract PCB and other analogs.

Developing an off-on fluorescence sensor based on red copper nanoclusters wrapped by sulfhydryl and polymer double ligands for sensitive detection of N-acetyl-L-cysteine

N-acetyl-L-cysteine (NAC) as a class of thiols is commonly used in the treatment of lung diseases, detoxification and prevention of liver damage. In this paper, 4-mercaptobenzoic acid (4-MBA) coated and polyvinylpyrrolidone (PVP) attached copper nanoclusters (4-MBA@PVP-CuNCs) were successfully synthesized using a simple one-pot method with an absolute quantum yield of 10.98 %, and its synthetic conditions (like effects of single/double ligands and temperature) were studied intensively. Then Hg2+ could quench the fluorescence of the 4-MBA@PVP-CuNCs and its fluorescence was restored with the addition of NAC. Based on the above principles, an off–on switching system was established to detect NAC. That is, the 4-MBA@PVP-CuNCs-Hg probe was prepared by adding Hg2+ to switch off the fluorescence of the CuNCs by static quenching, and then NAC was added to switch on the fluorescence of the probe based on the chelation of NAC and Hg2+. Moreover, the effects of metal ion types and mercury ion doses for the probe construction were also further discussed. The method showed excellent linearity in the range of 0.05–1.25 µM and low detection limit of 16 nM. Meanwhile, good recoveries in real urine, tablets and pellets were observed, which proved the reliability of the method and provided a convenient, fast and sensitive method for NAC detection.

Dual-source signal amplification electrochemiluminescence sensor combined with molecularly imprinted polymers for the imidacloprid detection

A novel lanthanide metal-organic-gel (MOG)-derived material/nitrogen-doped graphdiyne (Tb-Ru-MOG/CeO2/N-GDY) composite with a dual-source signal amplification strategy was prepared and used to construct a molecularly imprinted sensor based on bifunctional monomers for the detection of imidacloprid (IMI) using electrochemiluminescence (ECL). In a green reaction environment, terbium (III) (Tb3+) can undergo multiple coordination reactions with 4′-(4-carboxyphenyl)-2,2′:6′,2″-terpyridine (Hcptpy) and tris(4,4′-dicarboxylicacid-2,2′-bipyridyl) ruthenium (II) dichloride (Ru(dcbpy)32+), and combine with ceria nanoparticles (CeO2 NPs) to form Tb-Ru-MOG/CeO2. Within the Tb-Ru-MOG/CeO2 framework, energy transfer from the double ligands can sensitize the central Tb3+, triggering a distinct antenna effect and energy-transfer, and its polyporous configuration offered a nanoconfined space for Ce3+/Ce4+ to effectively catalyze coreactant radicals (S2O82−), leading to in-situ endogenous activation ECL reactions. The conductive N-GDY accelerated electron movement and increased the loading on the electrode surface, enhancing the exogenous excitation of the ECL signals. Leveraging the synergistic effect of the bifunctional monomer, the synthesized molecularly imprinted polymers (MIPs) ECL sensor demonstrated a wide detection range from 10 nM to 10,000 nM for IMI, with a limit of detection (LOD) of 1.37 nM, showcasing an innovative concept for the dual-source strategy of signal amplification in integrated ECL composites to analyze food and environmental hazards.

A Double‐ligand Chelating Strategy to Iron Complex Anolytes with Ultrahigh Cyclability for Aqueous Iron Flow Batteries

AbstractAqueous all‐iron flow batteries (AIFBs) are attractive for large‐scale and long‐term energy storage due to their extremely low cost and safety features. To accelerate commercial application, a long cyclable and reversible iron anolyte is expected to address the critical barriers, namely iron dendrite growth and hydrogen evolution reaction (HER). Herein, we report a robust iron complex with triethanolamine (TEA) and 2‐methylimidazole (MM) double ligands. By introducing two ligands into one iron center, the binding energy of the complex increases, making it more stable in the charge‐discharge reactions. The Fe(TEA)MM complex achieves reversible and stable redox between Fe3+ and Fe2+, without metallic iron growth and HER. AIFBs based on this anolyte perform a high energy efficiency of 80.5 % at 80 mA cm−2 and exhibit a record durability among reported AIFBs. The efficiency and capacity retain nearly 100 % after 1,400 cycles. The capital cost of this AIFB is $ 33.2 kWh−1 (e.g., 20 h duration), cheaper than Li‐ion battery and vanadium flow battery. This double‐ligand chelating strategy not only solves the current problems faced by AIFBs, but also provides an insight for further improving the cycling stability of other flow batteries.

A Double-ligand Chelating Strategy to Iron Complex Anolytes with Ultrahigh Cyclability for Aqueous Iron Flow Batteries.

Aqueous all-iron flow batteries (AIFBs) are attractive for large-scale and long-term energy storage due to their extremely low cost and safety features. To accelerate commercial application, a long cyclable and reversible iron anolyte is expected to address the critical barriers, namely iron dendrite growth and hydrogen evolution reaction (HER). Herein, we report a robust iron complex with triethanolamine (TEA) and 2-methylimidazole (MM) double ligands. By introducing two ligands into one iron center, the binding energy of the complex increases, making it more stable in the charge-discharge reactions. The Fe(TEA)MM complex achieves reversible and stable redox between Fe3+ and Fe2+ , without metallic iron growth and HER. AIFBs based on this anolyte perform a high energy efficiency of 80.5 % at 80 mA cm-2 and exhibit a record durability among reported AIFBs. The efficiency and capacity retain nearly 100 % after 1,400 cycles. The capital cost of this AIFB is $ 33.2 kWh-1 (e.g., 20 h duration), cheaper than Li-ion battery and vanadium flow battery. This double-ligand chelating strategy not only solves the current problems faced by AIFBs, but also provides an insight for further improving the cycling stability of other flow batteries.

Multi-response luminescent sensor with phenylenediacetic acid and bis-triazole ligand for the detection of Cr(VI), Fe(III) and nitroimidazole antibiotics in aqueous solutions

A novel complex of [Zn(L)(HEA)]n (1) has been successfully synthesized by hydrothermal method based on the double ligands of H2HEA (H2HEA = 1,2-Phenylenediacetic acid) and L (L = 1,1′-((2,4,6-trimethyl-1,3-phenylene)bis(methylene))bis(1H-1,2,4-triazole)). The single crystal structure of the complex was analyzed by X-ray single crystal diffraction, indicating that complex 1 was stacked into a 3D crystal structure through intermolecular π···π and C-H···π weak interaction. The complex was characterized by elemental analysis, infrared spectroscopy, PXRD and TGA. Additionally, fluorescence experiments showed that complex 1 could be used as a fluorescent probe for detecting Fe(III), Cr(VI), and Metronidazole (MDZ), Ornidazole (ODZ), Dimetridazole (DTZ) in aqueous solutions. Detection limits were obtained for ions (3.2×10−7 M for Cr2O72−, 5.4×10−7 M for CrO42− and 3.6 × 10−7 M for Fe3+) and nitroimidazole antibiotics (1.3×10−7 M for MDZ, 9.7×10−8 M for ODZ and 4.4×10−8 M for DTZ). The possible fluorescence quenching mechanism has been studied in the paper.

Advanced hollow structure with functional Interface of NiCoP/NC achieved superior hydroxide ion storage for high-rate supercapacitor

Sluggish reaction kinetics and poor structure stability are the main problems that hinder the application of transition metal phosphides. Differing from the traditional single ligand strategy, a hollow spherical NiCoP with large-scale NiCoP//NC interfaces (DL-NiCoP/NC) was synthesized through co-assembling metal-organic framework (MOF) of 2-methylimidazole and 5-aminotetrazole double ligands. The experimental and theoretical calculation results show that the hollow structure with rich NiCoP//NC interfaces adjusts the local electronic environment, increases the adsorption energy of NiCoP for OH− and effectively optimizes the surface/solution pathway for OH− transfer, which contributes to capacitive-controlled and diffusion-controlled reaction. Based on the above research, the electrochemical reaction process and structural evolution of DL-NiCoP/NC electrode were elucidated. Benefits from the synergistic effects of hollow structure and interfacial interaction, DL-NiCoP/NC electrode shows high specific capacitance (1551 F g−1 at 1 A g−1) and high-rate performance (78.1% capacitance retention at 30 A g−1). The assembled hybrid supercapacitor has favorable energy and power output (54.2 Wh kg−1 and 11,948.9 W kg−1), and excellent capacitance retention (83.7% after 8000 cycles). The fabricated pouch-type supercapacitor exhibited good application potential. This work provides a promising method to design structure with interface regulating for fast OH− storage materials.

Synergistic passivation of high stability CsPb(Br/I)3 perovskite quantum dots with double ligands for WLEDs

The all-inorganic perovskite CsPbI3 quantum dots are difficult to achieve pure red stable luminescence due to their poor lattice thermodynamic stability and non-radiative recombination loss caused by surface halide vacancies. Therefore, the pure red perovskites are usually achieved by mixing the composition of halides (Br and I). In this work, CsPb(Br/I)3 quantum dots (QDs) were synthesized by the hot-injection method under the synergistic effect of homophthalic acid (HA), 2-bromoethanesulphonic acid sodium salt (SBES), and oleylamine (OAm). By adjusting the molar ratio of passivates, the synergistic effect of multiple ligands can not only passivate the unliganded Pb2+-related defects on the surface of NCs, but also increase the formation energy of halide vacancies. Meanwhile, due to the bidentate structure of HA, smaller size of perovskites nanocrystals were obtained. Eventually, synergistic boost in device performance is achieved for color-by-blue white light-emitting diodes (WLEDs) with CIE coordinates of (0.3319, 0.3297) and have an external quantum efficiency (EQE) of 10.13%. This strategy paves an efficient way for improving the efficiency and stability of CsPb(Br/I)3 NCs.

Turning coordination environment of 2D nickel-based metal-organic frameworks by π-conjugated molecule for enhancing glucose electrochemical sensor performance

The design and synthesis of the high-efficiency electrochemical sensor is the key to electrochemical conversion technology. This work synthesized Ni-based metal-organic framework (Ni-MOF) nanosheets by a competitive double ligands hybridization strategy. They were used as precursors to construct Ni-MOF@Ni-2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) core@shell structures by introducing π - conjugated molecule, HHTP. EXAFS further confirmed the interaction between Ni atoms and hexahydroxytriphenylene molecules. This process helps to promote more exposure of its active sites and enhance its electrochemical performance to become a high-performance enzyme glucose sensor. After coating, glucose detection sensitivity increased from 139.82 to 2124.90 μA/(mM cm2). These findings lay the foundation for preparing two-dimension hybrid functional MOF materials.

Three Co (III) Complexes Based on Double Ligands: Crystal Structures and Their Derivatives Applied as Supercapacitor Electrode Materials

• Three Co (III) complexes (namely Co-1, Co-2 and Co-3) were prepared by facial hydrothermal methods. • The composites (C(N,O)/Co x O y ) were obtained via pyrolysis of Co-3. • Good cycling stability and higher specific capacitance of the composites were exhibited. Three Co (III) complexes based on double ligands {[Co(2,2’-bpy)(2,5-HPda) (2,5-Pda)]Cl·2H 2 O, namely Co-1; [Co(2,2’-bpy)(2,5-Pda) 2 ]·2H 2 O, namely Co-2; [Co(2,2’-bpy)(2,5-HPda)(2,5-Pda)]NO 3 ·H 2 O, namely Co-3} were synthesized by hydrothermal methods. Single crystal X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS) and energy dispersive spectrometer (EDS) were applied to confirm the components of the three complexes and the oxidation states of the central atom. Optical micrograph, powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrum (UV-vis) were used to characterize these complexes. The thermal stabilities of the three complexes were further evaluated by thermo gravimetric analysis (TG). Afterwards, Co-3 was calcined under a flow of nitrogen at 420 °C for 2 h and the composites (C(N,O)/Co x O y ) were formed. When the composites were used as electrode materials for supercapacitors, the results showed an excellent specific capacitance of 544 F·g −1 in 6 M KOH solution at a current density of 2 A·g −1 . The cycle tests showed that the specific capacitance retained well after 2000 cycles at 20 A·g −1 current density.

Ni-catalyzed hydroaminoalkylation of alkynes with amines

Allylic amines are versatile building blocks in organic synthesis and exist in bioactive compounds, but their synthesis via hydroaminoalkylation of alkynes with amines has been a formidable challenge. Here, we report a late transition metal Ni-catalyzed hydroaminoalkylation of alkynes with N-sulfonyl amines, providing a series of allylic amines in up to 94% yield. Double ligands of N-heterocyclic carbene (IPr) and tricyclohexylphosphine (PCy3) effectively promote the reaction.

Temperature sensitive properties and preparation of europium complexes with double ligands

Temperature sensitive paints (TSPs) are a class of rising materials for non-contact temperature measurement technology. Efficient complexes with remarkable luminescent properties play the core role in TSPs. Rare earth organic complexes are often used as probe molecules for TSPs because of their long fluorescence lifetime, narrow fluorescence emission peaks, high fluorescence intensity, and large Stokes shift. Herein, two europium-based complexes, Eu(PCCA)3 phen and Eu (PMCA)3 phen, were synthesized under hydrothermal conditions, using europium(III) oxide (Eu2 O3 ), p-chlorocinnamic acid (PCCA), p-methoxy cinnamic acid (PMCA) and 1,10-phenanthroline (phen) as raw materials. Two temperature sensitive paints (Eu(PCCA)3 phen/PMMA and Eu(PMCA)3 phen/PMMA) were obtained by the polymerization of methyl methacrylate (MMA) with different europium complexes. The structure, morphology, luminescent properties of the europium complexes and temperature quenching properties of the TSPs were characterized by infrared (IR) spectroscopy, scanning electron microscopy (SEM), and fluorescence spectroscopy. The fluorescence results show that both of the two TSPs have good temperature quenching performance in the range 20-100°C with high sensitivity 50-60°C and 80-90°C, respectively. Furthermore, the highest sensitivity of Eu(PCCA)3 phen/PMMA is greater than that of Eu(PMCA)3 phen/PMMA. This work can provide a universal way for preparing efficient TSPs in practical applications.

Synthesis optimization, structures of four cobalt complexes as precursor for preparing porous composite materials

Four cobalt-based complexes (C26H18ClCoN4O9, namely trans-O,O-1; C26H19CoN4O10, namely trans-O,O-2; C26H18CoN5O12, namely cis-O,O-1; C26H18CoN5O12, namely cis-O,O-2) were prepared by facial hydrothermal methods combined with the double ligands (Pda = pyridine 2,5-dicarboxylic acid, Phen = 1,10-phenanthroline) using different cobalt salts. Among these complexes, trans-O,O-1 and trans-O,O-2 are heterogeneous isomorphisms whose structures are identical with similar cell parameters and the same P-1 space group, while cis-O,O-1 and cis-O,O-2 are isomers which have the same molecular formula but different structures. The elemental oxidation states and complex structures were confirmed via X-ray photoelectron spectrometer (XPS) and single crystal X-ray diffraction (XRD). The synthesis process and the structure of the mesophases were analyzed. Furthermore, powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectrum analysis (UV–vis) were applied to characterize the products. Afterwards, trans-O,O-1 was selected and calcined under a flow of nitrogen showing that mesoporous composite structures (C(N,Cl)/CoO/Co) were formed when trans-O,O-1 was calcined at 500 ℃, which were further used as electrode materials for supercapacitors. The electrochemical performance of the mesoporous composite structures showed a high specific capacitance of 700F·g−1 in 6 M KOH solution at a current density of 1 A·g−1, and retained well after 2000 cycles at 20 A·g−1 current density.

Alendronate/cRGD-Decorated Ultrafine Hyaluronate Dot Targeting Bone Metastasis.

In this study, we report the hyaluronate dot (dHA) with multiligand targeting ability and a photosensitizing antitumor model drug for treating metastatic bone tumors. Here, the dHA was chemically conjugated with alendronate (ALN, as a specific ligand to bone), cyclic arginine-glycine-aspartic acid (cRGD, as a specific ligand to tumor integrin αvβ3), and photosensitizing chlorin e6 (Ce6, for photodynamic tumor therapy), denoted as (ALN/cRGD)@dHA-Ce6. These dots thus prepared (≈10 nm in diameter) enabled extensive cellular interactions such as hyaluronate (HA)-mediated CD44 receptor binding, ALN-mediated bone targeting, and cRGD-mediated tumor integrin αvβ3 binding, thus improving their tumor targeting efficiency, especially for metastasized MDA-MB-231 tumors. As a result, these dots improved the tumor targeting efficiency and tumor cell permeability in a metastatic in vivo tumor model. Indeed, we demonstrated that (ALN/cRGD)@dHA-Ce6 considerably increased photodynamic tumor ablation, the extent of which is superior to that of the tumor ablation of dot systems with single or double ligands. These results indicate that dHA with multiligand can provide an effective treatment strategy for metastatic bone tumors.

Highly Luminescent and Water-Resistant CsPbBr3–CsPb2Br5 Perovskite Nanocrystals Coordinated with Partially Hydrolyzed Poly(methyl methacrylate) and Polyethylenimine

All inorganic lead halide perovskite nanocrystals (PNCs) typically suffer from poor stability against moisture and UV radiation as well as degradation during thermal treatment. The stability of PNCs can be significantly enhanced through polymer encapsulation, often accompanied by a decrease of photoluminescence quantum yield (PLQY) due to the loss of highly dynamic oleylamine/oleic acid (OLA/OA) ligands. Herein, we propose a solution for this problem by utilizing partially hydrolyzed poly(methyl methacrylate) (h-PMMA) and highly branched poly(ethylenimine) (b-PEI) as double ligands stabilizing the PNCs already during the mechanochemical synthesis (grinding). The hydrophobic polymer of h-PMMA imparts excellent film-forming properties and water stability to the resulting NC-polymer composite. In its own turn, the b-PEI forms an amino-rich, strongly binding ligand layer on the surface of the PNCs being responsible for the significant improvement of the PLQY and the stability of the resulting material. Moreover, the introduction of b-PEI promotes a partial phase conversion from CsPbBr3 to CsPb2Br5 to obtain CsPbBr3/CsPb2Br5 nanocrystals with a core-shell-like structure. As-prepared PNCs solutions are directly processable as inks, while their PLQY drops only slightly from 75% in colloidal solution to 65% in films. Moreover, the final PNC-polymer film exhibits excellent stability against water, heat, and ultraviolet light irradiation. These superior properties allowed us to fabricate a proof of concept thin film OLED with h-PMMA/b-PEI-stabilized PNCs as an easily processable, narrowly emitting color conversion composite material.

High lithium anodic performance of flower-like carbon nanoflakes derived from MOF based on double ligands

Carbon-based anode materials with unique structure, high electrical conductivity, high Li storage performance and excellent cycling stability are promising alternatives to traditional graphite anode materials in lithium-ion batteries (LIBs). Here we report a flower-like carbon material with hierarchical structure that is prepared by carbonization of a flower-like Zn-based metal-organic framework (MOF). The 2D layered MOF network precursor, namely [Zn(BDC)(MelM)·(DMF)] (BDC = benzene dicarboxylic acid, MelM = 2-Methylimidazole), is constructed using two ligands under solvothermal conditions. As an anode material for LIBs, these carbon nanoflakes exhibit remarkable electrochemical performance (capacity, cyclability, and rate capability); the capacity of 902.5 mAh g−1 was retained after 200 cycles at a current density of 100 mA g−1. The remarkable performance results from the unique morphology of carbon nanoflakes which is beneficial for infiltration of electrolyte and the transportation of Li ions.

Ethane selective adsorbent Ni(bdc)(ted)0.5 with high uptake and its significance in adsorption separation of ethane and ethylene

We reported a novel ethane selective metal–organic framework material Ni(bdc)(ted)0.5 with a high uptake of C2H6 and a decent selectivity towards C2H6/C2H4 separation. This material was synthesized with double ligands (bdc and ted) by a hydrothermal method. Its C2H6 and C2H4 isotherms were subsequently measured. The BET surface area of the synthesized Ni(bdc)(ted)0.5 reached 1701m2/g. Successful assembling of the two organic ligands into Ni(bdc)(ted)0.5 was indicated by FT-IR. TGA indicated that Ni(bdc)(ted)0.5 was stable in the temperature region below 673K. Ni(bdc)(ted)0.5 exhibited decent adsorption capacities of C2H6 and C2H4 with a superior high C2H6 adsorption capacity of 6.93mmol/g at 100kPa. More importantly, it exhibited preferential adsorption of C2H6 over C2H4. Its C2H6/C2H4 adsorption selectivity was in the range of 2–7.8 at pressure below 100kPa, higher than the reported adsorbents possessing the characteristic of preferential adsorption of C2H6 over C2H4. In addition, the isosteric heat of C2H6 and C2H4 adsorption on Ni(bdc)(ted)0.5 were much lower compared to those π-complexation sorbents adsorbing olefin preferentially by binding with the π bond of olefin. The high ethane adsorption capacity, high ethane/ethylene selectivity and low isosteric heat of adsorption of Ni(bdc)(ted)0.5 would make it a promising adsorbent for the effective separation of ethane/ethylene.

Advancement of Targeted Ultrasound Contrast Agents and their Applications in Molecular Imaging and Targeted Therapy

In recent years, targeted ultrasound contrast agents (UCA) have emerged with the rapid development of contrast-enhanced ultrasound technology and bio-nanotechnology, showing good prospects for applications in molecular imaging and targeted therapy. The non-invasive treatment modality can reduce the drug dosage, toxicity and side effects, providing a new kind of methodology and approach for treatments, which will greatly expand the research and its applications. Targeted UCA have been developed rapidly in recent years, and a variety of new UCA appear, such as multi-functional UCA, multi-modal UCA, UCA with double ligands or more ligands, long-circulating UCA and immune type UCA, which meet growing clinical and research needs. The novel UCA have made a great progress and play an increasingly important role in molecular imaging. In this article, we reviewed the concepts of ultrasound molecular imaging, and summarized the applications of targeted UCA in molecular imaging and targeted therapy.

Simultaneous knockdown of multiple ligands of innate receptor NKG2D prevents natural killer cell–mediated fulminant hepatitis in mice

NKG2D activation plays an important role in initiating and maintaining liver inflammation, and blockade of NKG2D recognition becomes a promising approach to alleviate liver inflammation. Treatment by silencing NKG2D ligands on hepatocytes, but not NKG2D on circulating immune cells, is more liver-specific, and simultaneous knockdown of multiple NKG2D ligands on hepatocytes will be more efficient in liver disease intervention. Here, we constructed a single vector that could simultaneously express multiple short hairpin RNAs (shRNAs) against all murine NKG2D ligands including Rae1, Mult1, and H60. After hydrodynamic injection of plasmid containing the three shRNA sequences (shRae1-shMult1-shH60), also called pRNAT-shRMH, we found the expression of all three NKG2D ligands on hepatocytes was downregulated both on messenger RNA and protein levels. Moreover, natural killer (NK) cell-mediated NKG2D-dependent fulminant hepatitis of the mice was alleviated, along with inactivation of hepatic NK cells, by pRNAT-shRMH if compared with its counterpart RNA interference vectors against single or double ligands. The therapeutic efficacy of pRNAT-shRMH was equivalent to that of injecting three monoclonal antibodies against Rae1, Mult1, and H60. For better in vivo application, we constructed a recombinant adenovirus containing pRNAT-shRMH (called Ad-RMH) with efficient hepatotropic infection capacity and observed that Ad-RMH intravenous injection exerted a similar therapeutic efficiency as plasmid pRNAT-shRMH hydrodynamic injection. Noticeably, simultaneous knockdown of multiple human NKG2D ligands (MICA/B, ULBP2, and ULBP3) also significantly attenuated NK cell cytolysis against human NKG2D ligand-positive hepatocyte L-02 cells, suggesting a possible translation into human settings. Simultaneous knockdown of multiple ligands of NKG2D prevents NK cell-mediated fulminant hepatitis and is a potential therapeutic approach to treat liver diseases.

A supramolecular copper(II) compound with double bridging water ligands: synthesis, crystal structure, spectroscopy, thermal analysis, and magnetism

A complex of composition {[{Cu(NDC)(OH2)(tn)(μ-OH2)}2]·2H2O}∞ (1) and a mononuclear complex salt [Cu(OH2)2(tn)2](NDC)·3H2O (2), where NDC = 2,6-naphthalenedicarboxylate dianion and tn = 1,3-diaminopropane, were simultaneously crystallized from an aqueous solution of the copper(II) naphthalenedicarboxylate—1,3-diaminopropane—methanol system. The crystal and molecular structures of both complexes were determined by single-crystal X-ray diffraction. Compound (1) consists of a supramolecular coordination complex in which the monomeric unit is assembled from a homodinuclear Cu(II) bridged by two water ligands. The Cu(II) centers exhibit distorted octahedral coordination; the equatorial plane is provided by one chelating tn ligand, one NDC2− ligand, one μ-H2O while the axial positions are occupied by H2O and μ-H2O. Strong intra- and/or intermolecular hydrogen bonds, also involving the crystallization water molecules, together with π–π stacking interactions, are involved in building up the supramolecule. The solid structure of compound (2) includes three water molecules of crystallization, the counter ion NDC2−, and a Cu(II) cationic complex in which the metal is six-coordinated in an axially elongated octahedron defined by two chelating tn ligands in the equatorial plane and two water ligands in the axial positions. Thermal analyses of (1) show two significant weight losses corresponding to water molecules (lattice and coordinated), followed by the decomposition of the network.