Search

The need for a sensitive, selective, non-invasive and reversible fluorescent sensor for Zn2+ monitoring is addressed in this work. A novel guest-host system is developed, including a Zn2+ sensitive fluorescent probe, Zinpyr-1, embedded in a porous optically transparent hybrid film. The entrapped probe molecules are accessible and can interact with the external analyte. The immobilized Zinpyr-1 confirms its specificity and selectivity for Zn2+, as shown by sensing tests conducted in buffer solutions that mimic the ionic composition of biological media. The uniqueness of the developed sensor system lies in its reversibility, combined with a fast and selective response, allowing dynamic measurements of zinc concentrations in the 1 µM to 1 mM range within few tens of seconds. Unlike most Zn2+ sensors, this system is a film-based sensor, making it an interesting minimally invasive tool for future studies on how live cells cultured on it dynamically regulate the Zn2+ concentration under controlled physiological conditions. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells are innate immune cells that exhibit nonspecific cytotoxicity against target cells and are known to have less immune rejection when allogeneic transplantation is performed. Therefore, various attempts are made to utilize them as a novel immunotherapeutic agent. However, there is a limitation that cytotoxicity is relatively low compared to T cells, so there is a need to sufficiently increase cytotoxicity to utilize NK cells as adaptive cell therapy. Zinc plays a crucial role in regulating signal transduction in immune cells by modulating the activity of key signaling molecules, such as NF-κB, acting as a second messenger. However, practical applications in cell culture step faced challenges due to (1) the cytotoxicity of zinc ions, (2) the formation of zinc oxide precipitates, and (3) the decrease in pH of the culture media. In this study, we hypothesized that effective delivery of zinc ions to NK cells would alter their signal transduction, thereby enhancing their target cell-killing activity. To test this, we synthesized zinc-alginate hydrogel microspheres (Zn-ALG) using alginate with divalent cations as crosslinkers and co-cultured these microspheres with NK cells to assess changes in killing activity. After co-culturing with Zn-ALG at a concentration of 1 bead/mL for approximately 72 h, we observed a significant decrease in the expression of inhibitory receptor genes TIM-3 and PDCD1 on NK cells by 21% and 28%, respectively. Additionally, the tumor cell-killing activity of NK cells increased by approximately 23%, showing statistically significant improvement. [ABSTRACT FROM AUTHOR]

BACKGROUND: Our previous studies have found that poly(vinylidene fluoride) bionic periosteum prepared by electrospinning has good cytocompatibility, but its biocompatibility is unknown. OBJECTIVE: To evaluate the biocompatibility of poly(vinylidene fluoride) bionic periosteum doped with Zn2+ and Mg2+. METHODS: Poly(vinylidene fluoride), poly(vinylidene fluoride) bionic periosteum doped with 1% Zn2+, doped with 1% Mg2+, and doped with 1% (Zn2++Mg2+) were prepared by electrospinning to make bionic periosteum extract. SD rats were selected as the experimental subjects for hemolysis test, short-term systemic toxicity test, and heat source test. Guinea pigs were selected as the experimental subjects for skin sensitization test. The biocompatibility of bionic periosteum of four groups was tested. RESULTS AND CONCLUSION: (1) The hemolysis test results showed that the hemolysis rates of 1% Zn2+ poly(vinylidene fluoride), 1% Mg2+ poly (vinylidene fluoride), 1% Zn2++1% Mg2+ poly(vinylidene fluoride) bionic periosteum and poly(vinylidene fluoride) extract were (0.130±0.013)%, (0.149±0.020)%, (0.466±0.018)%, and (0.037±0.018)%, respectively, which met the hemocompatibility standard of biomaterials. (2) The results of short-term systemic toxicity test showed that the four groups of bionic periosteal extract had no toxic signs such as body mass reduction, food intake changes, and dyspnea in SD rats, and had no toxic effects on major organs of rats. (3) Heat source test results showed that after intervention with poly(vinylidene fluoride) bionic periosteum doped with 1% Zn2+, doped with 1% Mg2+, and doped with 1% (Zn2++Mg2+), and poly(vinylidene fluoride) bionic periosteum extract, the elevated body temperature values of SD rats were (0.133±0.058), (0.100±0.010), (0.300±0.010), and (0.300±0.017)°C, respectively. All were less than 0.6 °C, and the total temperature increase was less than 1.4*#176;C. (4) The results of skin sensitization test showed that no erythema or edema was observed under the skin of guinea pigs after the intervention of bionic periosteum extract of four groups. (5) The results showed that poly(vinylidene fluoride) and poly(vinylidene fluoride) bionic periosteum doped with Zn2+ and Mg2+ had good biocompatibility. [ABSTRACT FROM AUTHOR]

Tightly sealed peri‐implant gingival tissue provides a barrier against oral bacterial invasion, protecting the alveolar bone and maintaining long‐term implant survival. To investigate if zinc can enhance the integration between peri‐implant gingival tissue and abutment surface, we herein present novel zinc/chitosan/gelatin (Zn/CS/Gel) coatings prepared using the electrophoretic deposition (EPD) technique. The effect of these coatings on human gingival fibroblasts (hGFs) was investigated by culturing these cells on top of the EPD coatings. Surface characterization demonstrated that Zn2+ were released in a sustained and pH‐responsive manner. The preclinical cell culture evaluation of these coatings indicated that the zinc‐containing coatings enhanced cell migration, adhesion and collagen secretion of hGFs. Moreover, the zinc‐containing coatings exhibited antibacterial efficacy by inhibiting the growth of Porphyromonas gingivalis and reducing attachment of Staphylococcus aureus. Notably, zinc‐free CS/Gel coatings prevented attachment of P. gingivalis as well. The coatings were also shown to be cytocompatible with epithelial cells and osteoblasts, which are other relevant cell types which surround dental implants after clinical placement. Based on our findings, it can be concluded that Zn‐containing coatings hold promise to enhance the adhesion of gingival tissue to the implant surface, which may potentially contribute to the formation of a robust peri‐implant soft sealing counteracting bacterial invasion. [ABSTRACT FROM AUTHOR]

To elucidate the inhibition effects of Zn2+ and Cd2+ on the luciferin–luciferase reaction, we performed quantitative measurements of quantum yields and spectral shapes for in vitro firefly bioluminescence in aqueous solutions containing ZnSO4, ZnCl2, CdSO4, and CdCl2 at different concentrations. Particular care was taken toward the equilibrium between metal ions and enzyme proteins, anion difference, solubility, and uncertainty evaluation. The bioluminescence quantum yields decreased almost linearly to the concentration of Zn2+ and Cd2+ below 0.25 mM. No obvious difference was found between the chloride and sulfate anion solutions. We defined inhibition sensitivity as the decrease in relative quantum yield versus the concentration of metal ions, and they were determined to be 1.48 ± 0.13 and 1.13 ± 0.16/mM for Zn2+ and Cd2+, respectively. We estimated the detection limit of inhibition effects as the concentration of metal ions that decrease relative quantum yields by 10%, which were 0.07 mM (4 ppm) and 0.09 mM (10 ppm) for Zn2+ and Cd2+, respectively. The shape of the bioluminescence spectra changed sensitively with the increase in Zn2+ concentrations. The bioluminescence peak energy for 0.10‐mM Zn2+ was ~2.2 eV, while that for 0.25‐mM Zn2+ was ~2.0 eV. The shape of the spectra changed less sensitively with the increase in Cd2+concentrations, and the peak energy was at ~2.2 eV for Cd2+ concentrations of 0.10 and 0.25 mM. [ABSTRACT FROM AUTHOR]

A novel peptide‐based chemical fluorescence sensor L (Dansyl‐His‐Pro‐Thr‐Cys‐NH2) was designed and synthesized. This sensor exhibits an "On–Off–On" detection cycle to detect Cu2+, Zn2+, and S2− in solution. According to the chelation‐enhanced fluorescence (CHEF) mechanism, when Zn2+ is present, the fluorescence is significantly enhanced and a blue shift occurs, representing a "Turn‐On" phase of the fluorescence detection mode. Because copper ions (Cu2+) have a paramagnetic quenching sensing mechanism, the fluorescence of L quenches rapidly with the formation of the L‐Cu system, representing the "Turn‐Off" phase. The subsequent introduction of S2− to the L‐Cu system results in the recovery of the L‐fluorescence, thereby representing the second "Turn‐On" phase. As a peptide molecule, the sensor L has several advantages over other types of sensors, including water solubility, high sensitivity, and good biocompatibility, with a very low detection limit. The detection lines of Zn2+ and Cu2+ are 97 nM (R = 0.993) and 75 nM (R = 0.995), respectively. Additionally, the sensor does not exhibit any obvious cell toxicity. These results indicate that this peptide chemiluminescent sensor has the potential to be applied in in vivo detection. [ABSTRACT FROM AUTHOR]

Abstract As an important candidate for rechargeable energy storage devices, the large‐scale development of aqueous zinc ion batteries has been hindered by hydrogen evolution and uncontrollable dendrites of metal anodes. A novel ZnO‐SiO2 composite interface phase (Zn@ZSCP) with a double protective effect based on in situ synthesis by hydrothermal method is used to improve these difficulties. The hydrophilic SiO2 layer is beneficial to the dissolution of hydrated zinc ions and reduces the nucleation barrier during zinc deposition, while the stable ZnO layer helps to adjust the electric field distribution on the surface of the metal anode to further induce uniform zinc nucleation. The cycle life of the Zn@ZSCP||Zn@ZSCP symmetric battery based on this innovative interface phase modification is up to 2500 h. Even at a high current density of 8 mA cm−2, the symmetric battery still has a stable cycle life of more than 2000 h. The zinc‐iodine full battery based on Zn@ZSCP anode and low‐cost biomass‐derived porous carbon exhibits an excellent specific capacity and outstanding cycle stability. This simple and reasonable battery structure design not only improves the practicability of aqueous zinc ion batteries to a certain extent but also helps to develop more efficient and environmentally friendly zinc metal batteries.

The zinc-ion hybrid capacitor (ZIHC) is an emerging energy storage device that has attracted intense interest for the inherent merits of relatively higher energy density and power density. Herein, an excellent ZIHC based on the Nb2CTx anode and CNTs@MnO2 cathode has been rationally designed and fabricated successfully in this work. MnO2 nanoflakes were grown on carbon nanotubes (CNTs) directly with a hydrothermal approach. Then, the CNTs@MnO2 nanocomposite acted as a cathode in a zinc-ion battery. Nb2CTx, a kind of new layered compound in the MXene family, demonstrates excellent ion storage capability. The large interlayer space dramatically improves zinc-ion accessibility. A ZIHC with a Nb2CTx anode and a CNTs@MnO2 cathode displays an energy density of 96.7 Wh kg–1 (with 183.2 W kg–1) and a power density of 1156.3 W kg–1 (with 61 Wh kg–1), a capacitance retention of about 88.7% after 10,000 cycles, and a Coulombic efficiency of more than 98.5% in the whole cycling process. This strategy of designing the ZIHC may provide a promising route to create novel energy storage devices. [ABSTRACT FROM AUTHOR]

Phosphorus recovery is essential, especially from wastewater containing high levels of phosphorus from the semiconductor industries, food companies, and livestock. This study aims to determine how pH, Fe/P molar ratio, and Zn/P molar ratio affect the crystallization of ferrous phosphate. Response surface methodology—central composite design was utilized to optimize the recovery efficiency of ferrous phosphate in a fluidized bed crystallization reactor. The pH and Fe/P molar ratio were adjusted within the ranges of 3.8 to 9.6 and 0.58 to 3.40, respectively, for the fluidized bed crystallization. The Zn/P molar ratio parameter was set between 0.1 and 1.0 to evaluate the impact of zinc. Following optimization by response surface analysis, the phosphorus removal efficiency was nearly 100% at pH 7.3, Fe/P molar ratio of 2.5, and the phosphate crystal efficiency was 60.3% at pH 6.8, Fe/P molar ratio of 1.9. In addition, the study discovered that zinc ion would significantly reduce the efficiency of ferrous phosphate recovery during the crystallization process, with the maximum phosphate crystal efficiency declines to 47% at Zn/P molar ratio of 0.5. [ABSTRACT FROM AUTHOR]

Emerging energy storage devices are vital approaches towards peak carbon dioxide emissions. Zinc-ion energy storage devices (ZESDs), including zinc ion capacitors and zinc ion batteries, are being intensely pursued due to their abundant resources, economic effectiveness, high safety, and environmental friendliness. Carbon materials play their important role in the development of ZESDs, from cathode, electrolyte, to metallic Zn anode. Though thrilling development has been achieved in ZESDs, they still face the challenges of unsatisfactory capacity and kinetics for cathode, and irreversibility and low utilization rate of Zn anode. Hence, the roles of carbon materials in ZESDs are systematically discussed, starting with investigating carbons with different dimensions as cathodes and the corresponding strategies to improve their performance. Also, carbons as coatings or skeletons for other types of cathode materials are introduced. Besides, the functions of carbons in electrolyte development are explored. Further, the influence of carbon materials on Zn anode is elucidated with the corresponding operational mechanisms. Finally, an outlook for carbon materials in ZESDs is provided. We envision the presented minireview can pay way on exploring novel carbon research towards next-generation energy storage technologies. Highlights: • Zinc-ion energy storage devices (ZESDs) are powerful rechargeable alternatives towards sustainability. • Carbon materials play vital roles on addressing the critical challenges in ZESDs. • Incorporation of redox-active entities serve as a mainstream to enhance the performance of carbon nanostructures for cathodes in ZESDs. • Carbons with high chemical stability are imperative to explore new charge storage mechanism in ZESDs. • Reversibility of metallic Zn anode can be greatly improved by novel carbon coatings or hosts. [ABSTRACT FROM AUTHOR]

Two zinc complexes [Zn(LH)2(phen)] (1) and [Zn(L)(H2O)]n (2) (LH− = 2-hydroxy-5-((3-nitrophenyl)azo)-benzoate, phen = 1,10-phenanthroline) were synthesized by hydrothermal methods and characterized by elemental analysis and IR spectroscopy. Complexes 1 and 2 crystallize in mononuclear and polymeric structures, respectively, where ligands L2− are coordinated to the zinc ions via their carboxylate and phenolate groups in η2,μ2,κ2 and η2,μ2,κ1 mode, respectively. Introduction of the auxiliary chelating phen ligand results in the chelation of the zinc ions in 1 through both the phen ligand and the carboxylate group of the first LH− anion assisted further by the monodentate carboxylate group of the second LH− anion. In complex 2 the L2− anions act as tridentate ligands utilizing their carboxylate and phenolate groups to coordinate to three zinc ions. The phenolate oxygen atom bridges two zinc ions resulting in the generation of a layer structure. Fluorescence measurements have indicated that complexes 1 and 2 exhibit similar luminescence emissions around 393 and 387 nm, respectively, which originate from intra-ligand π-π* transitions. The emission intensities were strengthened relative to the sodium complex NaLH owing to the enhancement of the rigidity of the aromatic system through the coordination interactions of the ligands with the more tightly bound zinc ions. Furthermore, the suspension of complex 2 can be used to selectively detect Fe3+ cations via the luminescence quenching process. [ABSTRACT FROM AUTHOR]

The addition of specific ions has a significant effect on the characteristics and kinetics of hydrogen production by photofermentation (PFHP). In this article, a new basic research investigated by us find that adjusting the addition ratio of Zn2+ and Mn2+ ions in the R. sphaeroides HY01 system can effectively improve their biohydrogen production from xylose. The largest biohydrogen yield can be obtained as high as 219.2 mL/g xylose at concentration levels of 12 mg/L Zn2+ and 8 mg/L Mn2+. The shortest lag time is 5.76 h, along with most of the organic energy in the substrate transferred to H2. To evaluate the effect of Zn2+ and Mn2+, the Gompertz model with appropriately modification is applied on the photosynthetic bacteria R. sphaeroides HY01, and the corresponding constants are obtained by fitting the model, which is of great guiding significance for the optimization of fermentation conditions. [ABSTRACT FROM AUTHOR]

SUMMARY: Alcohol dehydrogenases (ADHs) are a group of zinc‐binding enzymes belonging to the medium‐length dehydrogenase/reductase (MDR) protein superfamily. In plants, these enzymes fulfill important functions involving the reduction of toxic aldehydes to the corresponding alcohols (as well as catalyzing the reverse reaction, i.e., alcohol oxidation; ADH1) and the reduction of nitrosoglutathione (GSNO; ADH2/GSNOR). We investigated and compared the structural and biochemical properties of ADH1 and GSNOR from Arabidopsis thaliana. We expressed and purified ADH1 and GSNOR and determined two new structures, NADH‐ADH1 and apo‐GSNOR, thus completing the structural landscape of Arabidopsis ADHs in both apo‐ and holo‐forms. A structural comparison of these Arabidopsis ADHs revealed a high sequence conservation (59% identity) and a similar fold. In contrast, a striking dissimilarity was observed in the catalytic cavity supporting substrate specificity and accommodation. Consistently, ADH1 and GSNOR showed strict specificity for their substrates (ethanol and GSNO, respectively), although both enzymes had the ability to oxidize long‐chain alcohols, with ADH1 performing better than GSNOR. Both enzymes contain a high number of cysteines (12 and 15 out of 379 residues for ADH1 and GSNOR, respectively) and showed a significant and similar responsivity to thiol‐oxidizing agents, indicating that redox modifications may constitute a mechanism for controlling enzyme activity under both optimal growth and stress conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Resistance to the inflammatory response is an important part of promoting the repair of damaged tissue and improving the local inflammatory response caused by medical bio-implant materials has been a key issue to be addressed in recent years. OBJECTIVE: To summarize the anti-inflammatory effects of common metal ions and related molecular mechanisms to provide some theoretical references for improving the early inflammatory response of hosts caused by bio-implant materials. METHODS: A computer search of the relevant literature in PubMed, Web of Science, CNKI and WanFang databases was conducted using “metal ions, magnesium ion, zinc ion, silver ion, copper ion, inflammation, anti-inflammatory effects, oxidative stress, immunoregulation, signaling pathways” as Chinese and English search terms. Preliminary screening was conducted by reading the titles and abstracts. Finally, 80 papers were included for result analysis and summary. RESULTS AND CONCLUSION: (1) Metal ions such as magnesium, zinc, silver and copper have a good anti-inflammatory effect. The strength of this antiinflammatory effect is strongly correlated with the dose and duration of action. In the future, consideration can be given to controlling the release rate of ions and adjusting the appropriate therapeutic concentration to achieve the best anti-inflammatory effect. (2) Magnesium ions and zinc ions exhibit excellent antiinflammatory activity, with magnesium ions often being beneficial in anti-inflammatory therapy in the form of compounds such as magnesium sulfate and zinc ions regulating the body’s inflammatory response with zinc feed as the main source of zinc supplementation. (3) Silver and copper ions have some antiinflammatory effects, but are still predominant for their excellent antibacterial activity, mainly in the form of nanoparticles and bio-coatings. (4) Magnesium and zinc metal ions can be combined with natural extracts to form complexes to exert anti-inflammatory effects, and this method has the advantage of being inexpensive and widely available and is a sustainable and green approach, which is worthy of clinical promotion. (5) Metal ions such as magnesium, zinc, silver and copper exert anti-inflammatory effects by reducing host oxidative stress damage, modulating immune cells and inhibiting inflammatory signaling pathways such as nuclear factor-κB, Toll-like receptor, STAT3 and NOD. (6) The molecular mechanism related to the anti-inflammation of metal ions is a complex network, which is not the effect of a single pathway, but should be a combination of multiple signaling pathways. There are still many potential mechanisms that have not yet been explored, and more systematic elucidation of the interconnections between various signaling pathways is needed in the future. [ABSTRACT FROM AUTHOR]

A new phenanthroline derivative bearing imidazole group, (2-(3,5-di(pyridin-4-yl)phenyl)-1-p-tolyl-1H-imidazo[4,5-f] [1,10]phenanthroline) has been devised. The derivative serves as a multifunctional probe, exhibiting a highly sensitive colorimetric response to Fe2+ ion and a selectively ratiometric fluorescent response to Zn2+ ion in a buffer-ethanol solution. The colorless-to-red visual color change upon addition of Fe2+ accompanied by enhanced absorption makes this derivative a suitable naked-eye sensor for Fe2+ ion. Moreover, the derivative displayed a Zn2+-induced red-shift of emission (44 nm), showing a color change from blue to light cyan under a 365-nm UV lamp. Its practical imaging applicability for intracellular Zn2+ was confirmed in HeLa cells using a confocal microscope. The improved emission properties and cell imaging capability would provide a new approach to fluorescence sensation for Zn2+. [ABSTRACT FROM AUTHOR]

In this study, a novel fluorescent probe DZ was designed by derivatizing from naphthaldehyde and benzoyl hydrazine. The probe exhibited a low detection limit of 1.75×10−8 mol/L for Zn2+ in ethanol systems. Due to its typical aggregation‐induced emission phenomenon, DZ showed exceptional efficacy in detecting the alcoholic strength of Chinese Baijiu, allowing for accurate differentiation between beverages with various alcohol contents in water/ethanol mixtures. In addition, DZ had been successfully utilized for the detection of Zn2+ in both test paper and environmental water samples. [ABSTRACT FROM AUTHOR]

The existing strategies for myocardial infarction therapy mainly focus on reinstating myocardial blood supply, often disregarding the intrinsic and intricate microenvironment created by elevated levels of reactive oxygen species (ROS) that accompanies myocardial infarction. This microenvironment entails cardiomyocytes apoptosis, substantial vascular cell death, excessive inflammatory infiltration and fibrosis. In such situation, the present study introduces a zinc-based nanozyme injectable multifunctional hydrogel, crafted from ZIF-8, to counteract ROS effects after myocardial infarction. The hydrogel exhibits both superoxide dismutase (SOD)-like and catalase (CAT)-like enzymatic activities, proficiently eliminating surplus ROS in the infarcted region and interrupting ROS-driven inflammatory cascades. Furthermore, the hydrogel's exceptional immunomodulatory ability spurs a notable transformation of macrophages into the M2 phenotype, effectively neutralizing inflammatory factors and indirectly fostering vascularization in the infarcted region. For high ROS and demanding for zinc of the infarcted microenvironment, the gradual release of zinc ions as the hydrogel degrades further enhances the bioactive and catalytic performance of the nanozymes, synergistically promoting cardiac function post myocardial infarction. In conclusion, this system of deploying catalytic nanomaterials within bioactive matrices for ROS-related ailment therapy not only establishes a robust foundation for biomedical material development, but also promises a holistic approach towards addressing myocardial infarction complexities. Myocardial infarction remains the leading cause of death worldwide. However, the existing strategies for myocardial infarction therapy mainly focus on reinstating myocardial blood supply. These therapies often ignore the intrinsic and intricate microenvironment created by elevated levels of reactive oxygen species (ROS). Hence, we designed an injectable Zn-Based nanozyme hydrogel with ROS scavenging activity for myocardial infarction therapy. ALG-(ZIF-8) can significantly reduce ROS in the infarcted area and alleviate the ensuing pathological process. ALG-(ZIF-8) gradually releases zinc ions to participate in the repair process and improves cardiac function. Overall, this multifunctional hydrogel equipped with ZIF-8 makes full use of the characteristics of clearing ROS and slowly releasing zinc ions, and we are the first to test the therapeutic efficacy of Zinc-MOFs crosslinked-alginate hydrogel for myocardial infarction. [Display omitted] [ABSTRACT FROM AUTHOR]

The present work demonstrates the determination of thorium (Th4+), zinc (Zn2+) and fluoride (F−) ions by employing a substituted tripodal terpyridine (TP) as a fluorescence sensor. The distinct fluorescence intensities of the free TP and TP‐M complexes (M=Zn2+or Th4+) with the same emission wavelength at 468 nm were observed in steady‐state photoluminescence (PL) spectra at pH 7.0 with a 1 : 3 ratio of metal to the ligand. A ratiometric dual fluorescence signals for Zn2+ and Th4+ were displayed by the probe TP at varied concentrations. Furthermore, the quantitative determination of F− ions was achieved through the addition of F− to the tripod‐terpyridine‐zinc complex (TP‐Zn2+) where the fluorescence intensity decreases gradually. Notably, the present work facilitates the LOD (limit of detection) as 1.1×10−10 M, 1.01×10−8 M and 3.18×10−10 M and further LOQ (limit of quantification) as 0.37×10−9 M, 0.33×10−7 M and 5.26×10−9 M for Zn2+, Th4+ and F− ions, respectively. The predicted absorption spectra of TP show HOMO to LUMO+2 electronic excitation at 358 nm whereas the complex TP‐Th4+ exhibits HOMO to LUMO+1 electronic excitation at 568 nm. [ABSTRACT FROM AUTHOR]

The specificity, programmability and biocompatibility of DNA materials make them advantageous for applications in bio-detection and drug delivery. To further expand the applications and synthesis methods of DNA materials, in this study, Zn2+/DNA self-assembled nanoparticles (ZDNPs) with tumor-responsive marker microRNA-21 (miR-21) are simply and efficiently synthesized by utilizing the cooperative interaction between DNA and metal ions. Through the specific complementarity of the DNA hairpin structure in ZDNPs with miR-21, the fluorescent signal is activated and Zn2+ is released, which result in intracellular ROS production and can be used for fluorescence imaging and oxidative stress therapy of tumor. The synthesized ZDNPs are uniformly shaped spherical particles that can effectively load Zn2+. Depending on the responsive experiment of ZDNPs to miR-21, it is verified that there is a good linear fluorescence response signal with specificity between ZDNPs and miR-21 concentration. The linear response range is 5~160 nmol/L, and the detection limit is 5 nmol/L. The intracellular effects of ZDNPs are also investigated, and the results show that they can perform responsive fluorescence imaging, and mediate apoptosis of tumor cells through the oxidative stress pathway. As for in vivo fluorescence imaging and tumor therapy, ZDNPs demonstrate specific and sustained tracing ability at tumor lesion sites and produce significant growth inhibition effects on tumor. [ABSTRACT FROM AUTHOR]

Cannabidiol (CBD) is a chemical obtained from Cannabis sativa; it has therapeutic effects on anxiety and cognition and anti-inflammatory properties. Although pharmacological applications of CBD in many types of tumors have recently been reported, the mechanism of action of CBD is not yet fully understood. In this study, we perform an mRNA-seq analysis to identify the target genes of CBD after determining the cytotoxic concentrations of CBD using an MTT assay. CBD treatment regulated the expression of genes related to DNA repair and cell division, with metallothionein (MT) family genes being identified as having highly increased expression levels induced by CBD. It was also found that the expression levels of MT family genes were decreased in colorectal cancer tissues compared to those in normal tissues, indicating that the downregulation of MT family genes might be highly associated with colorectal tumor progression. A qPCR experiment revealed that the expression levels of MT family genes were increased by CBD. Moreover, MT family genes were regulated by CBD or crude extract but not by other cannabinoids, suggesting that the expression of MT family genes was specifically induced by CBD. A synergistic effect between CBD and MT gene transfection or zinc ion treatment was found. In conclusion, MT family genes as novel target genes could synergistically increase the anticancer activity of CBD by regulating the zinc ions in human colorectal cancer cells. [ABSTRACT FROM AUTHOR]

Metal-binding proteins, including proteases, play critical roles in the replication and pathogenesis of RNA viruses. This study conducted a comprehensive analysis to elucidate the landscape of metalloproteins and identify metal-binding proteases within RNA viruses. The analysis revealed the presence of predicted metalbinding proteins in 19 significant RNA viral families, encompassing 45 viral genera and 375 viral species. The predicted metalloproteome primarily consisted of magnesium (47%) and zinc (40%) binding proteins, with manganese (11%) binding proteins also identified. Through advanced bioinformatics tools, a data set of 905 carefully selected metalloproteins underwent rigorous functional characterization. The prevalence of polyproteins (37%), RNA polymerases (22%), and proteases (10%) was observed. Furthermore, metal ion binding was achieved in viral structural, non-structural, and accessory proteins such as integrase and methyltransferase. The in-depth investigation focused on protease domains, identifying a refined set of 456 non-redundant protease domains. Among them, 78 protease domains were determined to possess metal-binding properties, with zinc and magnesium binding emphasized. The findings provide significant insights into metal-binding proteases' distribution and evolutionary patterns, particularly in major human RNA viral proteases. Sequence similarity network analysis highlighted the presence of different classes of peptidases in viral families, such as zinc-binding peptidase C30 in the coronaviridae family, including human coronavirus proteases, and peptidase C16 in all genera of coronaviruses. This comprehensive analysis sheds light on the immense potential of metal-binding proteases as therapeutic targets. Continued exploration of metal-binding proteomes will further enhance our understanding of metal-dependent biological processes and facilitate the development of innovative antiviral strategies. [ABSTRACT FROM AUTHOR]

Biofouling is a major concern in marine industries. The use of traditional toxic antifouling coatings is forbidden or severely restricted. This study aimed to provide a green and effective antifouling coating. The coating was prepared using a polydimethylsiloxane (PDMS) matrix and Cu-doped zinc sulfide (ZnS:Cu). Four samples with different ZnS:Cu contents (1, 10, 20, and 50 wt%) were prepared. Pristine PDMS (0 wt%) was used as the control. The results showed that all coatings had hydrophobic surfaces conducive to combating biofouling. In tests against B. Subtilis, the 1, 10, 20, and 50 wt% samples showed enhanced antifouling capabilities compared to the 0 wt% sample. In static and dynamic tests against Chlorella, the antifouling capability increased with increasing ZnS:Cu content and the 50 wt% sample showed the best antifouling capability. The possible antifouling mechanisms of these coatings include the release of ions (Zn2+ and Cu+), induction of deformation, and fluorescence emission. This study provides a reference for the application of Zn2+/Cu+ combinations to combat marine biofouling. [ABSTRACT FROM AUTHOR]

Cyclodextrin (CD) is an important guest material owing to the water solubility and biocompatibility. In the paper, an organic small molecule was synthesized. According to supramolecular self-assembly, the organic molecule was bounded to the cavity of Poly β-cyclodextrin, which was characterized by IR, SEM and TEM et al. After self-assembly interaction, the morphology has changed obviously comparing with precursors. Simultaneously, the supramolecular self-assembly complex exhibited good water solubility. Moreover, By Gaussian calculation, the high binding activity between organic molecule and cyclodextrin was confirmed. By fluorescence investigation, the supramolecular system showed high fluorescence sensing activity for Zn2+ in pure water environment, which could track the dynamic change of Zn2+ in organisms. In addition, the supramolecular system exhibited low cytotoxicity. The work provided an interesting pathway for constructing water-soluble and low cytotoxic fluorescence sensor for Zn2+. [ABSTRACT FROM AUTHOR]

Abstract Objectives The aim of this study was to evaluate the effects of zinc chloride (ZnCl2) at 20, 50, 100, and 200 μg/mL on the quality of seminal plasma‐free boar sperm stored at 17°C for 7 days and to explore the underlying mechanisms. Methods Boar sperm were collected and incubated in non‐capacitation/capacitation medium to analyze sperm quality. Results In the non‐capacitated state, the addition of ZnCl2 at 20 and 50 μg/mL improved the survival rate and plasma membrane integrity of boar sperm (p < 0.05). Compared to the control group, the addition of ZnCl2 significantly increased total antioxidative capacity and CuZn superoxide dismutase activity, while reducing the malondialdehyde content (p < 0.05). ZnCl2 at 100 and 200 μg/mL significantly decreased sperm motility, protein kinase A (PKA) substrate phosphorylation, and tyrosine phosphorylation. These proteins were mainly located on the mid‐pieces of the flagellum. The addition of ZnCl2 at 20 and 50 μg/mL conveyed a protective effect to boar sperm stored at 17°C. Furthermore, ZnCl2 at 100 and 200 μg/mL inhibited sperm motility via tyrosine phosphorylation, thus preventing the ‘capacitation‐like’ state. In the capacitated state, there was no change in PKA substrate phosphorylation and tyrosine phosphorylation of the mid‐pieces of the flagellum compared to the control groups, indicating that the addition of Zn2+ did not negatively affect capacitation of preserved sperm. Conclusions ZnCl2 showed protective capacity to the preservation extender used for boar sperm during the process of 17°C storage, and the optimal concentration of ZnCl2 for the preservation extender was 100 μg/mL.

Reaction of M(OAc)2·xH2O (M, x = Zn, 2 and Co, 4), 1,4-dihydro-5,6-dicyano-2,3-pyrazinedione (H2CN2pyzdione), and pyrazine (pyz) affords two compounds of the same molecular formula {[M(H2O)6][M(CN2pyzdione)2(pyz)]·6H2O}n (M = Zn for 1 and Co for 2) in which discrete units of [M(H2O)6]2+ are linked to one-dimensional chains of [M(CN2pyzdione)2(pyz)]2– via multiple O–H···O hydrogen-bonding interactions and M2+-bound H2O molecules in [M(H2O)6]2+ also serve as linkers of hydrogen-bonded interstitial H2O molecules. Remarkably, 1 crystallizes in the monoclinic crystal system, the similar crystal system and unit cell parameters as 2, but with a space group distinct from 1 and 2, i.e., 1 is the noncentrosymmetric space group C2, whereas 2 is the centrosymmetric space group C2/m. This polar structure for 1 is induced by the presence of alternating arrangements of distinguishable two axial Zn–N bonds within [Zn(CN2pyzdione)2(pyz)]2– chains. Indeed, solid-state circular dichroism spectra of 1 exhibit significant Cotton effects, as evidenced by the polar space group C2. Moreover, these Cotton effects show clear temperature-dependence depending on contents of H2O molecules of 1.

The local natural clay from Darbandikhan (DC) was evaluated as a possible adsorbent for the adsorption of Zn2+ in its natural state, after [acid activation (ADC), base activation (BDC), and after pillaring (TiPDC)] in the laboratory and Sulaimani city industrial zone sewage. X-ray Diffraction, X-ray Fluorescence (XRF), Fourier-Transform Infrared Spectroscopy, Thermal gravimetric analyses, and N2 physisorption analyses were used to study the effects of different clay treatments on the surface, and adsorptive properties of the clay. The modifications resulted mainly in the removal of the calcite content and a significant increase in the surface area from 24.38 to 30.65, 32.19, and 47.46 m2 g−1 for DC, ADC, BDC, and TiPDC respectively. The adsorbent materials were examined for their efficiency to remove Zn2+ contaminant from Sulaimani industrial zone sewage by a batch method. ADC and TiPDC presented more than 99.9% removal (from 308.0 to less than 0.01 μg/L) of Zn2+. The estimated kinetic parameters illustrate that there is a directly proportional between the adsorption capacity and temperature for Zn2 + ions adsorption by DC, ADC, BDC, and TiPDC. The thermodynamic study showed that the adsorption of Zn2+ was found to be spontaneous above 20 °C for adsorbent (∆G° = -ve), and endothermic (∆H° = + ve) with an increase in the randomness at the adsorbate-adsorbent contact layer (∆S° = + ve). The natural clay and the modified materials (ADC, BDC, and TiPDC) can be regarded as good adsorbents for removing Zn2+ from wastewater. [ABSTRACT FROM AUTHOR]

The effectiveness of low-cost biosorbent Blepharispermum hirtum for the removal of Zn(II) ions from aqueous solution was examined. To assess the impact of solution pH and temperature on biosorption capability, batch biosorption tests were conducted. The optimum conditions for biosorption were discovered at pH 6.0, 0.5 g/L of biomass, and 15 min of equilibrium duration. The biosorption data was well represented by Langmuir model with correlation coefficient of 0.9981 followed by Freundlich, Temkin and Dubinin--Radushkevich isotherms with the correlation coefficients of 0.9834, 0.9812 and 0.8790 respectively at a solution temperature of 303 K. According to the Langmuir isotherm model, the maximal adsorption capacities (qmax) for Zn(II) was 27.66 mg/g. The Fourier-transform infrared spectrometer (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to carry out the characterization studies of biosorbent Blepharispermum hirtum. Discrete aggregates developed on the surface of the biosorbent because of interaction with metal ions. Either electrostatic attraction or a complexation mechanism held the metal ions to the biosorbents' active sites. [ABSTRACT FROM AUTHOR]

The abuse of antibiotics makes bacterial infection an increasingly serious global health threat. Reactive oxygen species (ROS) are the ideal alternative antibacterial approach for quick and effective sterilization. Although various antibacterial strategies based on ROS have been developed, many of them are still limited by insufficient antibacterial efficiency. Here, we have developed an acid-enhanced dual-modal antibacterial strategy based on zeolitic imidazolate frameworks-8 (ZIF8) -derived nanozyme. ZIF8, which can release Zn2+, is chosen as the carrier to integrate glucose oxidase (GOx) and gold nanoparticles (Au NPs) which can produce ROS via a cascade catalytic reaction. Thus, the bactericidal capability of ROS and Zn2+ have been integrated. More importantly, gluconic acid, a “by-product” of the catalytic reaction, can generate an acidic environment to promote both the ROS-producing and Zn2+-releasing, enhancing the overall antibacterial performance further. This triple-synergistic strategy exhibits extraordinary bactericidal ability at a low dosage of 4 μg/mL (for S. aureus) and 8 μg/mL (for E. coli), which shows a great potential of MOF-derived nanozyme for efficient bacterial eradication and diverse biomedical applications.

As known, in the synthesis of conductive polyaniline polymer from aniline monomer, the polymerization medium must be acidic. In order to make the polymerization medium acidic, protonic acids such as HCl and H2SO4 are generally used. In this study, two acids have been used to make the polymerization medium acidic. One of them, as we know, is H2SO4 as a protonic acid. The other acid is the zinc ion, which is a Lewis acid. The metal ion has never been used for this purpose up to now. Two polyaniline polymers have been synthesized to prove that conductive polymers can also be synthesized in the presence of metal ions instead of protonic acid. One of them is the polyaniline polymer, synthesized in the presence of H2SO4(PANI). The other polymer is polyaniline polymer, synthesized in the presence of zinc ions as acid (PANI-Zn-PSS). The synthesized polymers have been characterized by using scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible spectrophotometer (UV-vis.), thermal analysis techniques (thermo-gravimetric analysis, TGA)/differential thermal analysis, DTA) and electrical conductivity measurements kit. The photocatalytic activities of polymers synthesized have been investigated by the degradation of methylene blue (MB) dye in aqueous medium under UV light. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to evaluate the effects of zinc chloride (ZnCl2) at 20, 50, 100, and 200 μg/mL on the quality of seminal plasma‐free boar sperm stored at 17°C for 7 days and to explore the underlying mechanisms. Methods: Boar sperm were collected and incubated in non‐capacitation/capacitation medium to analyze sperm quality. Results: In the non‐capacitated state, the addition of ZnCl2 at 20 and 50 μg/mL improved the survival rate and plasma membrane integrity of boar sperm (p < 0.05). Compared to the control group, the addition of ZnCl2 significantly increased total antioxidative capacity and CuZn superoxide dismutase activity, while reducing the malondialdehyde content (p < 0.05). ZnCl2 at 100 and 200 μg/mL significantly decreased sperm motility, protein kinase A (PKA) substrate phosphorylation, and tyrosine phosphorylation. These proteins were mainly located on the mid‐pieces of the flagellum. The addition of ZnCl2 at 20 and 50 μg/mL conveyed a protective effect to boar sperm stored at 17°C. Furthermore, ZnCl2 at 100 and 200 μg/mL inhibited sperm motility via tyrosine phosphorylation, thus preventing the 'capacitation‐like' state. In the capacitated state, there was no change in PKA substrate phosphorylation and tyrosine phosphorylation of the mid‐pieces of the flagellum compared to the control groups, indicating that the addition of Zn2+ did not negatively affect capacitation of preserved sperm. Conclusions: ZnCl2 showed protective capacity to the preservation extender used for boar sperm during the process of 17°C storage, and the optimal concentration of ZnCl2 for the preservation extender was 100 μg/mL. [ABSTRACT FROM AUTHOR]

Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) click chemistry and fluorescent probe are hot research topics of organic chemistry. Introducing it into undergraduate laboratory could help to cultivate creativity of students. However, how to avoid the use of azides is a great challenge to promote CuAAC click chemistry in undergraduate education. Herein, we report a modified CuAAC click reaction experiment for undergraduate laboratory teaching, featuring improved safety and interestingness. 5,7-dimethyltetrazolo[1,5-a]pyrimidine can be tautomerized into azide form in solution. Elegantly using this property could achieve the CuAAC reaction between 5,7- dimethyltetrazolo[1,5-a]pyrimidine and 4-acetylene anisole for the generation of triazole compound 5, avoiding the toxicity and explosive risk from the operation of azide compound. The synthesized compound 5 could selectively recognize zinc ions as a fluorescent probe. It is potentially useful for quantitative analysis of zinc ion concentration. [ABSTRACT FROM AUTHOR]

Calcite mesocrystals were proposed, and have been widely reported, to form in the presence of polymer additives via oriented assembly of nanoparticles. However, the formation mechanism and the role of polymer additives remain elusive. Here, inspired by the biomineralization process of sea urchin spine comprising magnesium calcite mesocrystals, we show that calcite mesocrystals could also be obtained via attachment of amorphous calcium carbonate (ACC) nanoparticles in the presence of inorganic zinc ions. Moreover, we demonstrate that zinc ions can induce the formation of temporarily stabilized amorphous nanoparticles of less than 20 nm at a significantly lower calcium carbonate concentration as compared to pure solution, which is energetically beneficial for the attachment and occlusion during calcite growth. The cation-mediated particle attachment crystallization significantly improves our understanding of mesocrystal formation mechanisms in biomineralization and offers new opportunities to bioprocess inspired inorganic ions regulated materials fabrication. Zinc was used as a cationic additive to mediate the crystallization of amorphous 3 calcium carbonate, leading to the formation of calcite mesocrystals via a particle 4 attachment crystallization mechanism. [ABSTRACT FROM AUTHOR]

In this work, an acylhydrazone derivative (QN62) was developed via the one-step condensation of 6-hydroxy-2-naphthoic hydrazide with quinoline-8-carboxaldehyde. The structure of the QN62 compound was characterized by 1H NMR, 13C NMR, HR-MS (ESI), and X-ray crystallography. As a dual-functional turn-on fluorescence chemosensor, QN62 exhibited rapid recognition for Zn2+ in DMSO-H2O (4:1, v/v) and Mg2+ in ethanol-H2O (9:1, v/v). The enhancement in fluorescence detection was associated with the coordination reaction between QN62 and the target ions, which promoted intramolecular charge transfer and prevented the CN isomerization process. Simultaneously, a rapid color change from colorless to yellowish-green or yellow under UV light (365 nm) was easily visible to the naked eye. Under optimal conditions, the limit of detection and limit of quantification were 32.3 nM and 97.8 nM for Zn2+ and 16.1 nM and 48.9 nM for Mg2+, respectively. The recognition mechanism was reasonably speculated based on analysis of the Job’s plot, HR-MS, 1H NMR, and density functional theoretical calculations. Utilizing silica-gel plates fabricated from the QN62 chemosensor, the visual and rapid identification of Zn2+ and Mg2+ was successfully achieved, which could provide a convenient approach for on-site detection in environmental fields. The QN62 chemosensor could also quantify trace amounts of Zn2+ and Mg2+ in water samples. Furthermore, the cell imaging experiments indicated that QN62 could effectively sense intracellular Zn2+ and Mg2+, providing potential applications in biological systems.

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A Schiff-base type fluorescent sensor (PLB3) was synthesized by nucleophilic addition-elimination between 2-hydroxy-1-naphthaldehyde and 5-chloro-2-aminopyridine. Single crystal X-ray diffraction analysis demonstrated keto-amine isomer was predominantly adopted. 8-Fold fluorescence-enhanced recognition for detecting Zn2+ was chelation enhanced fluoresce (CHEF) mechanism. Also, PLB3 could distinguish well Zn2+ from analogue Cd2+. Job's plot fluorescence titration and UV–Vis titration revealed the 1:1 stoichiometry between Zn2+ and PLB3. The association constant (Ka) and limit of detection (LOD) were 5.14 × 107 M−1 and 0.33 μM, respectively. The excellent selective and sensitive properties urge PLB3 to detect the trace amounts of Zn2+ in the environmental systems. [ABSTRACT FROM AUTHOR]

A Schiff-base type fluorescent sensor (PLB3) was synthesized by nucleophilic addition-elimination between 2-hydroxy-1-naphthaldehyde and 5-chloro-2-aminopyridine. Single crystal X-ray diffraction analysis demonstrated keto-amine isomer was predominantly adopted. 8-Fold fluorescence-enhanced recognition for detecting Zn2+ was chelation enhanced fluoresce (CHEF) mechanism. Also, PLB3 could distinguish well Zn2+ from analogue Cd2+. Job's plot fluorescence titration and UV–Vis titration revealed the 1:1 stoichiometry between Zn2+ and PLB3. The association constant (Ka) and limit of detection (LOD) were 5.14 × 107 M−1 and 0.33 μM, respectively. The excellent selective and sensitive properties urge PLB3 to detect the trace amounts of Zn2+ in the environmental systems. [ABSTRACT FROM AUTHOR]

The purpose of the current study was to evaluate the interaction between zinc ions and horseradish peroxidase (HRP) by ultraviolet-visible, fluorescence, circular dichroism, and FTIR spectroscopies. HRP conformation analysis revealed a noticeable decrease in α-helix from 47% for the free enzyme to 17% for HRP–Zn2+ and a reduction in tertiary structures of the enzyme through a Zn2+ interaction. Moreover, the fluorescence intensity of HRP was decreased significantly by Zn2+. The linear relationship of HRP emission data and inhibitor concentration indicated that the extinction process is linear and occurs uniformly with increasing Zn2+ concentration. The values of Kq for the zinc and HRP interaction were in the order of 1011 L/mol, which means that HRP fluorescence was quenched by Zn2+ through a static quenching mechanism. [ABSTRACT FROM AUTHOR]

Reaction of M(OAc)2·xH2O (M, x = Zn, 2 and Co, 4), 1,4-dihydro-5,6-dicyano-2,3-pyrazinedione (H2CN2pyzdione), and pyrazine (pyz) affords two compounds of the same molecular formula {[M(H2O)6][M(CN2pyzdione)2(pyz)]·6H2O}n (M = Zn for 1 and Co for 2) in which discrete units of [M(H2O)6]2+ are linked to one-dimensional chains of [M(CN2pyzdione)2(pyz)]2– via multiple O–H···O hydrogen-bonding interactions and M2+-bound H2O molecules in [M(H2O)6]2+ also serve as linkers of hydrogen-bonded interstitial H2O molecules. Remarkably, 1 crystallizes in the monoclinic crystal system, the similar crystal system and unit cell parameters as 2, but with a space group distinct from 1 and 2, i.e., 1 is the noncentrosymmetric space group C2, whereas 2 is the centrosymmetric space group C2/m. This polar structure for 1 is induced by the presence of alternating arrangements of distinguishable two axial Zn–N bonds within [Zn(CN2pyzdione)2(pyz)]2– chains. Indeed, solid-state circular dichroism spectra of 1 exhibit significant Cotton effects, as evidenced by the polar space group C2. Moreover, these Cotton effects show clear temperature-dependence depending on contents of H2O molecules of 1. [ABSTRACT FROM AUTHOR]