Anion Release Research Articles

Light-driven anion-pumping rhodopsin with unique cytoplasmic anion-release mechanism

Microbial rhodopsins are photoreceptive membrane proteins found in microorganisms with an all-trans-retinal chromophore. The function of many microbial rhodopsins is determined by three residues in the third transmembrane helix called motif residues. Here, we report a group of microbial rhodopsins with a novel Thr–Thr–Gly (TTG) motif. The ion-transport assay revealed that they function as light-driven inward anion pumps similar to halorhodopsins previously found in archaea and bacteria. Based on the characteristic glycine residue in their motif and light-driven anion-pumping function, these new rhodopsins are called glycylhalorhodopsins (GHRs). X-ray crystallographic analysis found large cavities on the cytoplasmic side, which are produced by the small side-chain volume of the glycine residue in the motif. The opened structure of GHR on the cytoplasmic side is related to the anion releasing process to the cytoplasm during the photoreaction compared to canonical halorhodopsin from Natronomonas pharaonis (NpHR). GHR also transports SO42– and the extracellular glutamate residue plays an essential role in extracellular SO42– uptake. In summary, we have identified TTG motif-containing microbial rhodopsins that display an anion-releasing mechanism.

Effects of uric acid on oxidative stress in vascular smooth muscle cells.

Hyperuricemia during hypertension is associated with aberrant vascular functions and increased oxidative stress, which affects endothelial dysfunction. Nevertheless, the molecular mechanisms underlying the effects of uric acid on vascular smooth muscle cells (VSMCs) through oxidative stress remain unclear. The aim of the present study was to investigate the dose- and time-dependent effects of uric acid on oxidative stress and p53 protein expression in VSMCs. VSMCs were incubated with various concentrations of uric acid (0-50 mg/dl) for different time periods (1-24 h). Thiobarbituric acid reactive substances (TBARs), protein carbonylation and nitric oxide (NO) levels were determined using appropriate assay kits. Superoxide anion release was detected using the Görlach method. Western blotting was performed to determine the protein expression levels of p53. The findings demonstrated that the application of uric acid led to an increase in protein carbonylation and superoxide anion levels while causing a decrease in NO levels. Conversely, no significant effect was observed on TBARS levels. Additionally, it was observed that high concentrations of uric acid suppressed p53 expression at 6, 12 and 24 h. The present study provided evidence that the influence of uric acid on oxidative stress was more closely associated with time than dose; however, not all effects observed were strictly time-dependent.

Assembly of Dye Molecules in Covalent Organic Frameworks for Enhanced Colorimetric Biosensing.

Colorimetric assays have been extensively investigated for biosensing applications due to their advantages of visual recognizability, ease of use, and low cost. However, advancing their development is a great challenge due to the inherent limitations of colorimetric dyes. Herein, we report a strategy to assemble dyes in covalent organic frameworks (COFs) to effectively reinforce the applicability of pH-responsive dyes in colorimetric bioassays. Experimental results reveal that three-dimensional COFs can promote the assembly of dyes through hydrogen bonding, resulting in the formation of a dye-supermolecule@COF assembly. Consequently, when sensitized at increased pH levels (e.g., hydroxyl ions), disruption of hydrogen bonds may trigger a rapid transition from their insoluble fixed state within the COFs into soluble, visibly detectable dye anions. This process can also be facilitated by increased hydrophilicity and elevated electrostatic repulsion between the dye anions and COFs, leading to the substantial release of chromogenic dye anions from the COF pores into the solution, thereby amplifying the colorimetric signal output. Therefore, by employing various synthesized dye-supermolecule@COFs as signal tags, we developed a colorimetric bioassay capable of accurately identifying breast cancer cell subtypes. This study not only highlights the effectiveness of dye-supermolecule@COFs in enhancing colorimetric biosensing but also underscores the potential of employing the COF-mediated dye assembly strategy for colorimetric assays.

Signaling by Neutrophil G Protein-Coupled Receptors that Regulate the Release of Superoxide Anions.

In human peripheral blood, the neutrophil granulocytes (neutrophils) are the most-abundant white blood cells. These professional phagocytes are rapidly recruited from the bloodstream to inflamed tissues by chemotactic factors that signal danger. Neutrophils, which express many receptors that are members of the large family of G protein-coupled receptors (GPCRs), are critical for the elimination of pathogens and inflammatory insults, as well as for the resolution of inflammation leading to tissue repair. Danger-signaling molecular patterns such as the N-formylated peptides that are formed during bacterial and mitochondrial protein synthesis and recognized by formyl peptide receptors (FPRs) and free fatty acids recognized by free fatty acid receptors (FFARs) regulate neutrophil functions. Short peptides and short chain fatty acids activate FPR1 and FFA2R, respectively, while longer peptides and fatty acids activate FPR2 and GPR84, respectively. The activation profiles of these receptors include the release of reactive oxygen species (ROS) generated by the NADPH oxidase. Activation of the oxidase and the production of ROS are processes that are regulated by proinflammatory mediators, including TNFα and GM-CSF. The receptors have signaling and functional similarities, although there are also important differences, not only between the two closely related neutrophil FPRs, but also between the FPRs and the FFARs. In neutrophils, these receptors never walk alone, and additional mechanistic insights into the regulation of the GPCRs and the novel regulatory mechanisms underlying the activation of NADPH oxidase advance our understanding of the role of receptor transactivation in the regulation of inflammatory reactions.

Real-time monitoring of cellular superoxide anion release in THP-1 cells using a catalytically amplified superoxide dismutase-based microbiosensor.

Reactive oxygen species (ROS) including the superoxide anion (O2•-) are typically studied in cell cultures using fluorescent dyes, which provide only discrete single-point measurements. These methods lack the capabilities for assessing O2•- kinetics and release in a quantitative manner over long monitoring times. Herein, we present the fabrication and application of an electrochemical biosensor that enables real-time continuous monitoring of O2•- release in cell cultures for extended periods (> 8h) using an O2•- specific microelectrode. To achieve the sensitivity and selectivity requirements for cellular sensing, we developed a biohybrid system consisting of superoxide dismutase (SOD) and Ti3C2Tx MXenes, deposited on a gold microwire electrode (AuME) as O2•- specific materials with catalytic amplification through the synergistic action of the enzyme and the biomimetic MXenes-based structure. The biosensor demonstrated a sensitivity of 18.35 nA/μM with a linear range from 147 to 930nM in a cell culture medium. To demonstrate its robustness and practicality, we applied the biosensor to monitor O2•- levels in human leukemia monocytic THP-1 cells upon stimulation with lipopolysaccharide (LPS). Using this strategy, we successfully monitored LPS-induced O2•- in THP-1 cells, as well as the quenching effect induced by the ROS scavenger N-acetyl-L-cysteine (NAC). The biosensor is generally useful for exploring the role of oxidative stress and longitudinally monitoring O2•- release in cell cultures, enabling studies of biochemical processes and associated oxidative stress mechanisms in cellular and other biological environments.

Mineralogical insights into anion and cation dissolution behavior in calcium arsenic residue from copper smelting: Implications for safe disposal

This study investigates the dissolution behavior of calcium-arsenic residue (CAR) sourced from a copper smelter in China, crucial for its safe disposal. Using mineralogical analysis, we identified fine powders, medium particles, and varying crystallinity in lumps, with calcium arsenate oxides comprising 56.03 % of the total weight. Arsenic dissolution is predominantly influenced by arsenic-containing mineral phases, with calcium arsenate oxides serving as the primary controlling phase. Other cations, including copper, zinc, calcium, and lead, behave according to their respective mineral phases. At a leaching pH of 3, concentrations of heavy metal ions such as As, Zn, Cu, and Pb exceed permissible limits set by the United States Environmental Protection Agency (USEPA), reaching approximately 3500, 155, 30, and 7.5 mg/L, respectively. The release of fluoride and chloride anions remains consistent throughout the system, largely unaffected by pH variations, at approximately 10 and 200 mg/L, respectively. Additionally, the competitive interaction between SO42- and AsO43- for Ca2+ ions promote SO42- dissolution, leading to morphological changes in gypsum (CaSO4·2 H2O). Under acidic conditions (pH=3), there's an increase in gypsum volume, with SO42- leaching concentration around 1100 mg/L, while under alkaline conditions (pH=12), the SO42- leaching concentration increases to around 4400 mg/L due to the dominance of AsO43-. Kinetic analysis suggests that arsenic release involves a combination of diffusion and interfacial mass transfer. Overall, this study provides valuable insights into the characterization and dissolution behavior of CAR-related minerals, offering comprehensive data support for their safe disposal and landfilling.

A novel biological antibacterial polyvinyl alcohol/polyionic liquid hydrogel for wound dressing.

The release of antibiotics or anions by traditional bacteriostatic agents led to the development of bacterial drug resistance and environmental pollution. Ionic liquids (ILs) have become important choices for antibacterial agents because of their excellent physical, chemical and biological properties. In this paper, the bioactivities of 1-vinyl-3-butylimidazolium chloride ([VBIM]Cl, IL) and poly (1-vinyl-3-butylimidazolium chloride) (P[VBIM]Cl, PIL) were evaluated, and the potential antibacterial material was used to synthesize hydrogels. Using the colony formation assay and the Oxford cup method, antibacterial effect of IL and PIL were tested. Cell-Counting-Kit-8 (CCK-8) experiments were used to study the IC50 (half maximal inhibitory concentration) values of IL and showed 1.47mg/mL, 0.35mg/mL and 0.33mg/mL at 24 h, 48 h and 72 h, respectively. The IC50 value of PIL were 12.15μg/mL, 12.06μg/mL and 11.76μg/mL at 24 h, 48 h and 72 h, respectively. The PIL is further crosslinked with polyvinyl alcohol (PVA) to form a novel hydrogel through freeze-thaw cycles. The newly fabricated hydrogel exhibited a high water content, excellent water absorption properties and outstanding mechanical performance. Using the colony formation assay and the inhibition zone assay, the hydrogels exhibited favorable antibacterial effects (against E.coli and S.aureus) such that nearly 100% of the bacteria were killed in liquid medium while cultivating with H4 (synthesized by 0.5g PIL and 1g PVA). In addition, the cytotoxicity of PIL was significantly reduced through hydrogen bond crosslinking. H4 showed the highest antibacterial activity and a good biocompatibility. The results indicated that the PVA&PIL hydrogels had great potential for wound dressing.

In silico investigation of herbicide release from intercalated layered double hydroxides

Excessive pesticide use may contaminate streams and surface water, posing a significant danger for the environment. The employment of slow-deliver formulations may circumvent this issue by reducing pesticide waste. In this work, computational simulations were performed to study the release of anionic herbicide species from the galleries of layered double hydroxides. Density Functional Theory was initially employed to construct the structural models of intercalated materials, which were later used for force-field based molecular dynamics. The calculated Gibbs free energy of the anion release indicated that the herbicide species are spontaneously exchanged with carbonate anions, demonstrating that the final intercalation with CO32− is favored. The molecular dynamics runs showed that the basal spacing increases in the presence of an aqueous solution, in certain cases even swelling the interlayer region. Based on the acquired data, a simple mechanism could be proposed for the release of anion species from layered materials.

Mineralocorticoid receptor promotes cardiac macrophage inflammaging

Inflammaging, a pro-inflammatory status that characterizes aging and primarily involving macrophages, is a master driver of age-related diseases. Mineralocorticoid receptor (MR) activation in macrophages critically regulates inflammatory and fibrotic processes. However, macrophage-specific mechanisms and the role of the macrophage MR for the regulation of inflammation and fibrotic remodeling in the aging heart have not yet been elucidated. Transcriptome profiling of cardiac macrophages from male/female young (4 months-old), middle (12 months-old) and old (18 and 24 months-old) mice revealed that myeloid cell-restricted MR deficiency prevents macrophage differentiation toward a pro-inflammatory phenotype. Pathway enrichment analysis showed that several biological processes related to inflammation and cell metabolism were modulated by the MR in aged macrophages. Further, transcriptome analysis of aged cardiac fibroblasts revealed that macrophage MR deficiency reduced the activation of pathways related to inflammation and upregulation of ZBTB16, a transcription factor involved in fibrosis. Phenotypic characterization of macrophages showed a progressive replacement of the TIMD4+MHC-IIneg/low macrophage population by TIMD4+MHC-IIint/high and TIMD4–MHC-IIint/high macrophages in the aging heart. By integrating cell sorting and transwell experiments with TIMD4+/TIMD4–macrophages and fibroblasts from old MRflox/MRLysMCre hearts, we showed that the inflammatory crosstalk between TIMD4– macrophages and fibroblasts may imply the macrophage MR and the release of mitochondrial superoxide anions. Macrophage MR deficiency reduced the expansion of the TIMD4– macrophage population and the emergence of fibrotic niches in the aging heart, thereby protecting against cardiac inflammation, fibrosis, and dysfunction. This study highlights the MR as an important mediator of cardiac macrophage inflammaging and age-related fibrotic remodeling.

Repeated Aqueous Film-Forming Foams Applications: Impacts on Polyfluoroalkyl Substances Retention in Saturated Soil.

Historical practices at firefighter-training areas involved repeated aqueous film-forming foams (AFFFs) applications, resulting in source zones characterized by high concentrations of perfluoroalkyl and polyfluoroalkyl substances (PFAS). Repeated applications of AFFF composed of 14 anionic and 23 zwitterionic perfluoroalkyl substances (PFAS) were conducted on a single one-dimensional saturated soil column to quantify PFAS retention. An electrofluorination-based (3M) Milspec AFFF, which was above the mixture's critical micelle concentration (CMC), was at application strength (3%, v/v). Retention and retardation of PFAS mass increased with each successive AFFF addition, although the PFAS concentration profiles for subsequent applications differed from the initial. Greater degree of mass retention and retardation correlated with longer PFAS carbon-fluorine chain length and charged-headgroup type and as a function of AFFF application number. Anionic PFAS were increasingly retained with each subsequent AFFF application, while zwitterionic PFAS exhibited an alternating pattern of sorption and desorption. Surfactant-surfactant adsorption and competition during repeat AFFF applications that are at concentrations above the CMC resulted in adsorbed PFAS from the first application, changing the nature of the soil surface with preferential sorption of anionic PFAS and release of zwitterionic PFAS due to competitive elution. Applying a polyparameter quantitative structure-property relationship developed to describe sorption of AFFF-derived PFAS to uncontaminated, saturated soil was attempted for our experimental conditions. The model had been derived for data where AFFF is below the apparent CMC and our experimental conditions that included the presence of mixed micelles (aggregates consisting of different kinds of surfactants that exhibit characteristics properties different from micelles composed of a single surfactant) resulted in overall PFAS mass retained by an average of 27.3% ± 2.7% (standard error) above the predicted values. The correlation was significantly improved by adding a "micelle parameter" to account for cases where the applied AFFF was above the apparent CMC. Our results highlight the importance of interactions between the AFFF components that can only be investigated by employing complex PFAS mixtures at concentrations present in actual AFFF at application strength, which are above their apparent CMC. In firefighter-training areas (AFFF source zones), competitive desorption of PFAS may result in downgradient PFAS retention when desorbed PFAS become resorbed to uncontaminated soil.

Insight into ion exchange behavior of LDHs: Asynchronous chloride adsorption and intercalated ions release processes

Cl− adsorption and intercalated ions release processes during LDHs are highly intricate phenomena. In this study, ion exchange performance of LDHs with specific cation interlayers and intercalated anions (CaAl–NO3-LDHs, CaAl–NO2-LDHs, CaFeAl–NO3-LDHs and CaFeAl–NO2-LDHs) were extensively investigated. The results indicate that in the presence of low chloride concentration, the intercalated anions are prematurely released due to partial dissolution of LDHs in neutral deionized water and ion exchange with OH− in alkaline simulated concrete pore solution. Therefore, Cl− adsorption of LDHs and release process of intercalated anions in LDHs are not completely synchronized. Compared to partial LDHs dissolution, the accelerating effect of OH− exchange on intercalated anion release in simulated concrete pore solution is more pronounced. Further, higher stability of LDHs in testing solutions is mainly corresponding to higher binding energy between intercalation ions and cation interlayers, thus saturated Cl− adsorption content of NO3-LDHs with high binding energy is higher than NO2-LDHs with low binding energy, and saturated Cl− adsorption content of CaAl-LDHs with high binding energy is higher than CaFeAl-LDHs with low binding energy in testing solutions.

Structural features and dynamic behaviour of the interlayer space of layered double hydroxide coatings

Layered double hydroxide (LDH) offer great potentialities to design functional coatings with customizable properties by exploiting their anion exchange properties. We investigated the anion exchange properties and expansion capacity of the interlayer space relating to the starting film morphology. ZnAl LDH coatings of different thicknesses and morphologies were first obtained by an in situ method using Al-based substrates. When the anion to intercalate is relatively bigger than the starting nitrates, the intercalation may be constrained by the initial LDH particle size and density composing the film. After optimising the morphology, the intercalation of three functional anions with potential antimicrobial properties was successfully achieved with an expansion of the interlayer space up to 150 % while holding the coating integrity. The release of the guest anion was studied by immersion in physiological saline solution. Finally, the possibility to regenerate the coating was demonstrated supporting the potential of these hybrid coatings for applications.

Durable Cation Replenishing to Activate Anion Releasing for Enhanced Electrochemical Performance of Dual‐Ion Full Batteries

AbstractDual‐ion batteries, as one of the most promising alternatives to Li‐ion batteries, face severe challenges in terms of side reactions, particularly at the anode. These side reactions result in the consumption of limited cations and the deactivation of anions in graphite during cycling. To date, most reports are focused on reducing these side reactions. Here, a new way is proposed to achieve the stable cycling of dual‐ion batteries using Mg as an example. Mg can be oxidized to Mg2+ during the discharge process, thereby replenishing the cation loss due to the side reactions. Meanwhile, anions are released from graphite to maintain the charge balance in the electrolyte. Another advantage is that the formation of Li3Mg7 during cycles facilitates Li plating/stripping. Therefore, Mg||Graphite exhibits a high Coulombic efficiency (≈96.5%) and a stable cycling performance (≈94.6% after 1700 cycles at 2 C) even without prelithiation, much better than Cu||Graphite and Graphite||Graphite. The mechanism also works for other active metals, such as K, Ca, and Na. The results demonstrate the promising potential of this strategy.

Unprecedented anti-inflammatory biscembranoids with 3-hydroperoxy-3-methylcyclohex-1-ene moiety isolated from aquaculture Sarcophyton trocheliophorum

Recent advancements in the discovery of natural products have made significant progress in rapidly identifying known compounds from complex extracts using advanced spectroscopic technologies. Among these methods, one powerful approach called MS/MS molecular networking (MN) organizes chemical similarity based on MS/MS fragmentation data, serving as a valuable complement to traditional dereplication strategies. In our ongoing research focused on lead discovery from a sustainable medicinal source, an aquaculture soft coral Sarcophyton trocheliophorum, the MN profiling approach revealed the chemical diversity of biscembranoid analogs. By analyzing the MN pattern, biscembranoid derivatives with unique MS/MS fragments were prioritized for further investigation. Two novel biscembranoids, sarcotroxide A (1) and B (2), were successfully obtained through targeted isolation. These novel biscembranes contained an unprecedented 3-hydroperoxy-3-methylcyclohex-1-ene moiety compared with all biscembranoid analogs. The chemical structures of the two new biscembranoids were confirmed through spectroscopic analyses and in silico calculations. Their anti-inflammatory properties were assessed against the generation of superoxide anion (O2•−) and elastase release in activated human neutrophils. Sarcotroxides A (1) and B (2) exhibited anti-inflammatory activity by inhibiting O2•− accumulation (with 43.67% and 61.62% inhibition) and elastase release (with 38.21% and 61.62% inhibition) at 10 µM. These findings validated the potential of these biscembranoids from the cultured S. trocheliophorum as promising candidates for the future development of anti-inflammatory agents specifically designed to target neutrophils.

A novel PPARβ/FFA1 dual agonist Y8 promotes diabetic wound healing

BackgroundDiabetes ulcer is one of the leading causes of disability and death in diabetics. Y8 [(2-(2-fluoro-4-((4-methyl-2-(4-(trifluoromethyl)phenyl)thiazol-5-yl)methoxy) phenoxy)acetic acid)], a dual agonist of peroxisome proliferation activated receptorβ (PPARβ) and free fatty acid receptor 1 (FFA1/FFAR1/GPR40), a new compound molecule with the potential for diabetes ulcer treatment. ObjectiveTo research the effect of the dual target agonist Y8 and its mechanism of action in the treatment of diabetic ulcers. MethodsWe have established a wound model in diabetic mice. After treatment with Y8, wound healing was evaluated by tissue pathology, reactive oxygen species (ROS) levels, and gene expression testing. Under high sugar conditions, the mechanism of Y8 affecting fibroblasts' proliferation and keratinocytes' migration is further studied. ResultsWe found that Y8 accelerated wound healing and shortened healing time in diabetic mice. Granulation tissue generation and extracellular matrix (ECM) deposition were significantly increased in Y8-treated mice. Mechanistically, Y8 promotes keratinocyte proliferation by activating PPARβ and migration of keratinocytes by triggering FFA1 in vitro. In addition, Y8 also decreased ROS levels in fibroblasts in vitro and in vivo by activating PPARβ, reducing their release of superoxide anions. ConclusionOur results suggest that PPARβ/FFA1 dual agonist Y8 has the effect of promoting the healing of diabetic ulcer wounds in vivo and in vitro, and its therapeutic effect is better than that of single-target agonists.

Illumination Enhanced Crystallization and Defect Passivation for High Performance CsPbI3 Perovskite Solar Cells by Sacrificing Dye

AbstractAll‐inorganic perovskite solar cells (PSCs) have been the research focus due to their high thermal stability and proper band gap for tandem solar cells. However, their power conversion efficiency (PCE) is still lower than that of organic‐inorganic hybrid PSCs. Herein, a sacrificing dye (Rhodamine B isothiocyanate, RBITC) is developed to regulate the growth of perovskite film by in situ release of ethylammonium cations, isothiocyanate anions and benzoic acid molecules upon annealing and illumination. The ethylammonium cations can efficiently passivate surface defects. The isothiocyanate anions incorporate with uncoordinated Pb to regulate the crystallization process. The benzoic acid molecules facilitate the nucleation of the perovskite crystals. Especially, the illumination can accelerate the release of these beneficial ions/molecules to improve the quality of perovskite films further. After optimization with RBITC, a high open circuit voltage (VOC) of 1.24 V and a champion PCE of 20.95% are obtained, which are among the highest Voc and PCE values of CsPbI3 PSCs. Accordingly, the operational stability of the PSC devices is significantly improved. The results provide an efficient chemical strategy to regulate the formation of perovskite films in whole crystallization process for high performance all‐inorganic PSCs.

Assessment of the Antibacterial Potential of Layered Double Hydroxides

Microbes play a crucial role in our lives, and certain pathogenic bacteria are responsible for a wide range of infectious illnesses, food safety, and environmental damage. Layered double hydroxide (LDH), a type of natural two-dimensional substance with a distinctive layered structure also known as anionic clays, has been established as a material that may be utilized to battle a variety of bacterial infections. The interesting properties of LDH include their ease of synthesis, unique structure, uniform distribution of different metal cations in the brucite layer, surface hydroxyl groups, flexible tunability, intercalated anions with interlayer spaces, swelling properties, oxo-bridged linkage, and high chemical and thermal stability, ability to intercalate different types of anions (inorganic, organic, biomolecules, and even genes), delivery of intercalated anions. In the field of biomaterials, LDH has gained prominence as a significant class of layered materials with promising applications. Here, emphasis has been placed on factors such as biocompatibility, anion exchange with the target ion, holding of guest species in the interlayer space, and controlled anion release in a given medium. By utilizing LDH's inherent biocompatibility, several studies have improved its antibacterial characteristics, enabling researchers to add active substances into its matrix for the treatment of bacterial-caused disease. Despite the fact that LDH's antibacterial capabilities have been the subject of several studies, there are currently very few reviews of such findings. Therefore, this study reviewed current developments in new LDH techniques to enhance their antimicrobial activity and provided background on their structures.

Caffeic Acid-Zinc Basic Salt/Chitosan Nanohybrid Possesses Controlled Release Properties and Exhibits In Vivo Anti-Inflammatory Activities.

Caffeic acid (CA) exhibits a myriad of biological activities including cardioprotective action, antioxidant, antitumor, anti-inflammatory, and antimicrobial properties. On the other hand, CA presents low water solubility and poor bioavailability, which have limited its use for therapeutic applications. The objective of this study was to develop a nanohybrid of zinc basic salts (ZBS) and chitosan (Ch) containing CA (ZBS-CA/Ch) and evaluate its anti-edematogenic and antioxidant activity in dextran and carrageenan-induced paw edema model. The samples were obtained by coprecipitation method and characterized by X-ray diffraction, Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and UV-visible spectroscopy. The release of caffeate anions from ZBS-CA and ZBS-CA/Ch is pH-dependent and is explained by a pseudo-second order kinetics model, with a linear correlation coefficient of R2 ≥ 0.99 at pH 4.8 and 7.4. The in vivo pharmacological assays showed excellent anti-edematogenic and antioxidant action of the ZBS-CA/Ch nanoparticle with slowly releases of caffeate anions in the tissue, leading to a prolongation of CA-induced anti-edematogenic and anti-inflammatory activities, as well as improving its inhibition or sequestration antioxidant action toward reactive species. Overall, this study highlighted the importance of ZBS-CA/Ch as an optimal drug carrier.

Effects of Zinc-Layered Hydroxide on Controlled Release of Plant Nutrients and Growth Performance of Kelempayan (Neolamarckia cadamba) Seedlings

The loss of nutrients from conventional fertilisers is often encountered by the agricultural industry. Slow-release fertilisers by nanotechnology application can maintain nutrient availability for effective plantgrowth. Zinc-layered hydroxide nanohybrids have been little explored as controlled release systems offunctional anions, unlike the Layered Double Hydroxides (LDH) that belong to the same family ofanionic clays. The objective of the study was to investigate the effectiveness of zinc-layered hydroxidenanohybrid containing plant nutrient anions as a controlled-release formulation. Two nano-deliverymaterials namely zinc-layered hydroxide nitrate (ZLN) and zinc-layered hydroxide phosphate (ZLP) weresuccessfully synthesised through the co-precipitation and anion exchange methods. The PXRD patterns ofthe resulting nanohybrids, ZLN and ZLP recorded basal spacing of 9.57 and 6.78Å, respectively, at alower 2 angles range of 0-60 o . FTIR analyses confirmed the formation of host-guest nanohybrid whichcomprised the characteristic bands of nitrate and phosphate. Thermogravimetric analyses showed thethermal stability of the nanohybrid obtained where the capability of the host material to function as acontrolled release agent was determined through a controlled release study. Controlled release of plantnutrient sources, nitrate and phosphate from their respective nanohybrids were evaluated using variousrelease medium solutions. The accumulated release of guest anion from interlayer zinc layered hydroxide(ZLH) nanohybrid into pH 4 solution was observed to be faster than pH 6.5. A higher concentration ofsodium carbonate solution showed an increase in the percentage release for both nitrate and phosphateanions into the release medium. A plant growth trial using Kelempayan (Neolamarckia cadamba)seedlings showed that treatment with ZLN and ZLP recorded the highest biomass weight compared toapplication with commercial fertiliser and raw chemicals. The content of N, P and Zn in Kelempayanleaves showed the highest readings for similar treatment. The study found that ZLH has acted as a goodhost for inorganic plant nutrients with slow-release properties and thus has improved the growthperformance of Kelempayan seedlings with better nutrient uptake.

Quercetin and histamine effects of the content of superoxide anion and ATP in the blood plasma of rats

Background. Histamine is one of the versatile biogenic amines with multiple roles in the immune response and allergic disorders. Histamine and ATP can act as ligands in the body. In plasma, ATP is a potent vasodilator that stimulates the formation of NO and prostaglandins and, very importantly, can offset local sympathetic vasoconstriction. Adenosine triphosphate is released into plasma from erythrocytes and endothelial cells, and the plasma concentration increases in both the feed artery and the vein draining the contracting skeletal muscle. Taking this into account, it is important to study the effect of histamine in combination with quercetin, which inhibits the release of histamine from cellular depots, on the content of the superoxide anion and ATP in the blood plasma. Materials and Methods. Nonlinear white male rats were used for the experimental studies. Quercetin solutions were added to whole blood to a final concentration of 0.1; 0.3; 0.5; 1; 3; 5 mM. In other experiments, histamine solution was added to the blood to final concentration of 0.01; 0.1; 1; 10 μM. In a series of experiments, histamine (0.01 and 10 μM) and quercetin (0.1; 0.5; 3; 5 mM) were added to the blood in various possible combinations. Blood plasma was used in each experimental group. The blood to which saline was added was used as control. The content of superoxide anion and adenosine triphosphate was measured in the selected samples. Results and Discussion. Histamine, quercetin, as well as their combined action lead to the intensification of superoxide anion generation in the blood plasma of rats. Quercetin is known to be an antioxidant, but some of our studies have shown the opposite effect. Quercetin causes an increase in the ATP content in the blood plasma of rats. Histamine causes the same effect only at concentrations of 0.1 and 10 µM. Likewise, the combined administration of histamine and quercetin into the blood increased the ATP content. The results of ANOVA test prove that both histamine and quercetin have the same effect on the release of superoxide anion and ATP from blood cells into plasma. Their combined action only strengthens the effect of releasing the studied products. Conclusion. Quercetin, histamine and their combined action cause an increase in the generation of superoxide anion and ATP in the blood plasma of rats.