Chelate Effect Research Articles

Enhancing Adsorption Performance of Ce(III) by Amine-Thiourea and Aniline-Modified Magnetic Chitosan Nanocomposites.

To enhance the adsorption performance of chitosan for rare earth ions, two novel magnetic chitosan-based adsorbents were prepared by using chitosan-coated magnetic silica nanoparticles modified with amine-thiourea and aniline. The structure of copolymers was analyzed using characterization methods such as X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis, confirming the successful synthesis of modified magnetic chitosan nanocomposites. The investigation explored the influence of pH, contact time, dosage, initial concentration, and temperature on the adsorption performance. Comparative studies revealed a significantly enhanced adsorption performance after modification. The chitosan-coated magnetic silica nanoparticles modified with aniline (PAN-CS/Fe3O4@SiO2) reached adsorption saturation in about 120 min with a capacity of 136 mg/g, while the chitosan-coated magnetic silica nanoparticles modified with amine-thiourea (TSC-CS/Fe3O4@SiO2) exhibited a higher adsorption capacity of 156 mg/g for Ce(III). Both materials demonstrated strong agreement with the Langmuir isotherm model and pseudo-second-order kinetics. Thermodynamic analysis indicated that Ce(III) adsorption is both spontaneous and endothermic. Examination of the adsorption mechanisms suggested that the effective adsorption of Ce(III) is due to the strong synergistic effects of chelation and electrostatic interactions involving amino, carboxyl, and hydroxyl groups. This study demonstrates that chitosan modified with amine-thiourea and aniline is an effective approach to significantly enhance the rare earth ion adsorption by chitosan.

Rapid method for screening of both calcium and magnesium chelation with comparison of 21 known metal chelators.

Chelation is the rational treatment modality in metal overload conditions, but chelators are often non-selective and can, hence, cause an imbalance in the homeostasis of physiological metals including calcium and magnesium. The aim of this study was to develop an affordable, rapid but sensitive and precise method for determining the degree of chelation of calcium and magnesium ions and to employ this method for comparison on a panel of known metal chelators. Spectrophotometric method using o-cresolphthalein complexone (o-CC) was developed and its biological relevance was confirmed in human platelets by impedance aggregometry. The lowest detectable concentration of calcium and magnesium ions by o-CC was 2.5μM and 2μM, respectively. The indicator was stable for at least 110days. Four and seven out of twenty-one chelators strongly chelated calcium and magnesium ions, respectively. Importantly, the chelation effect of clinically used chelators was not negligible. Structure-activity relationships for eight quinolin-8-ols showed improvements in chelation particularly in the cases of dihalogen substitution, and a negative linear relationship between pKa and magnesium chelation was observed. Calcium chelation led to inhibition of platelet aggregation in concentrations corresponding to the complex formation. A novel method for screening of efficacy and safety of calcium and magnesium ion chelation was developed and validated.

A novel synthetic compound, deferiprone–resveratrol hybrid (DFP-RVT), promotes hepatoprotective effects and ameliorates iron-induced oxidative stress in iron-overloaded β-thalassemic mice

A high amount of iron in β-thalassemia patients can lead to oxidative stress and organ dysfunction, especially liver, the main iron accumulated organ. Iron catabolism causes the generation of reactive oxygen species (ROS), triggering liver inflammation, fibrosis, and cirrhosis. Deferiprone-resveratrol hybrid (DFP-RVT) is chemically synthesized by combining deferiprone (DFP) and resveratrol (RVT) which shows an iron-chelating property along with antioxidant activity. This study explored the hepatoprotective effect of DFP-RVT in iron overloaded β-knockout (BKO) thalassemic mice. The results revealed that DFP-RVT treatment improved liver function in iron-overloaded BKO mice by reducing liver enzymes and increasing hepcidin levels compared to iron overload control mice. Both DFP alone and DFP-RVT treatment groups demonstrated iron chelation effects by decreasing liver iron content (LIC), iron profiles, and iron deposition in the liver. Moreover, DFP-RVT powerfully showed antioxidant properties by decreasing liver and plasma thiobarbituric acid reactive substances (TBARs) and increasing reduced glutathione (GSH) and superoxide dismutase (SOD). Interestingly, transforming growth factor β1 (TGFβ1), which can contribute to chronic liver disease through liver injury, inflammation, fibrosis, and cirrhosis, is highly expressed in iron-overloaded mice. However, both DFP and DFP-RVT treatment significantly reduced TGFβ1 levels compared to the iron-overloaded group. Therefore, DFP-RVT could be a potent hepatoprotective compound through the mobilization of iron, reduction of ROS, improvement of liver enzymes, and alleviation of liver damage, potentially relieving liver dysfunction in iron-overloaded BKO mice.

Evaluation of a novel non-ionic graft starch-based antiscalant in reduction of CaSO4 scaling by static and reverse osmosis test

A novel nonionic starch-based antiscalant (St-g-GMA) was designed and obtained by graft copolymerization of starch and glycidyl methacrylate (GMA). St-g-GMA not only achieved an obvious reduction of CaSO4 scaling in static test, but also effectively mitigated the flux decrease in dynamic reverse osmosis (RO) system. This improvement is ascribed to the grafted poly(GMA) chains on St-g-GMA. A suitable grafting ratio of this starch-based antiscalant achieve a high performance cost in control of CaSO4 scaling. Combination of the apparent antiscaling performance, observation under scanning electron microscopy, energy dispersive x-ray spectroscopy unit, x-ray diffraction pattern, conductivity measurement, and dispersion experiment, the scale-inhibition mechanism of St-g-GMA was investigated and mainly attributed to chelation, dispersion and lattice distortion effects. The oxygen-containing groups on poly(GMA) chains such as epoxy groups can chelate with Ca2+, causing the induction time of crystallization prolonged; St-g-GMA with the distinct branched chain configuration can well disperse the formed microcrystal of CaSO4. Moreover, molecular dynamics simulations confirmed that the grafted poly(GMA) chains well bind to the crystal surfaces and the oxygen-containing groups could even enter the crystal lattice to inhibit the crystal growth and change the morphologies. St-g-GMA still mitigated the flux decrease notably in treatment of a synthetic seawater during a 24-h RO measurement. This study provided an efficient, environmentally-friendly and low-cost antiscalant with high application potentials.

Effect of chelator on carbon sequestration and mechanical properties of CO2-cured cement pastes with different pore structures

Chelator can accelerate the mineralization reaction of cement-based materials, playing a positive role in reducing CO2 emissions into the atmosphere. Cement pastes with different pore structures were prepared by adjusting the water cement ratio, and effects of chelator on the microstructure, phase composition, carbon sequestration and mechanical properties of CO2-cured cement pastes with different pore structures were investigated in this study. The results indicated that chelator could promote CO2 transport in dense cement paste with more gel pore and transition pore and medium dense cement paste with many transition pore and capillary pore, and induce mineralization reaction to repair larger pores in loose cement paste with more capillary pore and megalopore (LCM). Chelator had the most significant effect on improving the performance of cement paste of LCM, increasing the carbonation sequestration rate and compressive strength of cement paste cured for 48 h by 19.0 % and 28.1 %, respectively.

Comparative analysis and mechanistic insights into polysorbate 80 stability differences in biopharmaceutical buffer systems

Polysorbate 80 (PS80) is a non-ionic surfactant extensively utilized in biopharmaceutical formulations for stabilizing proteins. However, PS80 degradation has become a widespread concern throughout the industry over the past decade. In this work, the impact of most frequently employed pH/buffer systems on the stability of PS80 was assessed. PS80 degraded fastest in histidine buffer, followed by acetate and succinate buffers, whereas it remained stable in citrate, phosphate and tris buffers. When there was PS80 degradation, the extent of degradation was found to be pH-dependent. The predominant degradation pathway was oxidation mainly triggered by metal ions. The varying stability of PS80 across different pH/buffer systems was attributed to the role of buffer agents, which can either promote or inhibit the oxidation process through their interactions with metal ions. Specifically, buffers except histidine exhibited metal ion chelation similar to ethylenediaminetetraacetic acid (EDTA), which can suppress the oxidation of PS80, although the effectiveness of chelation varies to different extents. Furthermore, the binding capacity appeared stronger at higher pH in acetate and succinate buffers. Conversely, histidine was reported to form pro-oxidant complexes with metal ions to accelerate PS80 degradation, especially at higher pH levels. Our work for the first time offers a comprehensive understanding of PS80 oxidation in biopharmaceutical buffer systems. This provides a strong foundation for buffer and excipient selection in parenteral formulations.

Polyacrylonitrile nanofibrous mat modified with cysteamine and ionic liquid as a recyclable and efficient adsorbent for selective removal of sulfonamides and Cu(II) from aqueous solution: Roles of multi-function adsorption

The combined contamination of heavy metals and antibiotics is a prevalent occurrence, yet the distinct chemical characteristics of these substances pose a significant obstacle to their simultaneous elimination. In this work, novel polyacrylonitrile nanofibrous mat (NFsM) modified with cysteamine and ionic liquid (IL@Cys@PAN NFsM) was developed using a cascade thiol-ene click reaction. The IL@Cys@PAN NFsM exhibits a rich array of functional groups and demonstrates strong binding affinity, fast mass transfer, and exceptional selectivity for sulfonamides (SAs) and Cu(II). The maximum adsorption capacities for SAs and Cu(II) in single-component systems were 122.3 and 97.4 mg/g respectively, according to the Langmuir isotherm model. The time dependent adsorption capacities followed a pseudo-second-order kinetic model, demonstrating a chemisorption-dominant process for each analyte. In binary pollutant systems, the co-occurrence of SAs and Cu(II) in water produced a competitive effect; however, the decrease in adsorption capacity was minimal. Through experimental analysis, FTIR characterization and density functional theory (DFT) studies, reasonable interactions of hydrogen-bond, electrostatic interactions, π-π stacking for SAs, and chelation effect for Cu(II) were proposed. Additionally, the reusability and recyclability of IL@Cys@PAN NFsM enhance its practicality for real-world applications. This paper presents the first systematic study on the simultaneous adsorption of heavy metals and antibiotics using NFsM, offering a novel perspective on the design of custom adsorbents capable of efficiently removing multiple contaminants with diverse characteristics while balancing eco-friendliness, excellent adsorption performance, and impressive recyclability for wastewater remediation.

The strong metal-support interaction at Ni–O–Pt interface facilitates rapid electrocatalytic hydrogen production

Electrocatalytic water splitting technology, as an essential method for storing and converting renewable energy, has garnered significant attention. However, traditional electrolytic water splitting is hampered by issues such as noble metal catalysts are expensive and unstable, limiting its widespread application. To address this challenge, this study proposes an innovative method that utilizes nickel metal-organic framework (Ni-MOF) as a support to firmly anchor platinum (Pt) nanoparticles on its surface. This approach not only overcomes the high cost and instability associated with traditional noble metal catalysts but also leverages the strong chelation effect of ethylenediaminetetraacetic acid disodium salt (EDTA·2Na) and the strong metal-support interaction (SMSI) at the Ni–O–Pt interface, prompting catalysts to possess excellent stability and catalytic activity. The catalyst exhibits excellent performance in promoting the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall electrolysis of water, maintaining stability throughout the entire electrochemical process. At a current density of 10 mA cm−2, the overpotentials for HER and OER with Pt1·5/Ni-MOF are only 29 mV and 234 mV, respectively. When Pt1·5/Ni-MOF serves as both the cathode and anode for overall water splitting, only a low voltage of 1.557 V is needed. This study offers fresh insights into the development of stable, efficient, and low-budget dual-functional catalysts for water electrolysis, with the potential to drive the commercialization of water electrolysis technology and make significant contributions to the advancement of clean energy.

Smear Layer Removing and Pulp Dissolving Ability of Sodium Hypochlorite Mixed with Two Etidronate-Containing Irrigants in Continuous Chelation Technique

The study aimed to assess the effect of two etidronate-containing irrigants and EDTA on the ability of sodium hypochlorite (NaOCl) to remove the smear layer and dissolve organic tissues. This study evaluated the following solutions: distilled water, 3% NaOCl, 3% NaOCl + EDTA, and 3% NaOCl mixed with etidronate powder from two manufacturers [Dual Rinse, (DR); IsraDent, (ID)] to obtain 9%, 15%, and 18% solutions. To assess the proteolytic activity, bovine muscle tissue samples (56.1 ± 5.4 mg; n = 10 per group) were immersed in the tested solutions for 15 min. Absolute weight changes and percentages of weight changes (wt%) were calculated. To assess smear layer removal, the root canals of human wisdom teeth were instrumented, irrigated with the tested solutions (n = 10 per group), and evaluated using SEM. Statistical analysis employed an ANOVA with a post-hoc Tukey test and paired t-test, the Kruskal–Wallis test with a pairwise Wilcoxon rank sum test, and the Friedman test with a pairwise Wilcoxon signed-rank test. The mean weight loss in the NaOCl group comprised 17.3 mg (32 wt%). Sequential use of NaOCl and EDTA resulted in a significant increase in proteolytic activity of the former (57 wt%), while mixing these solutions led to a reduction of proteolytic activity (17 wt%). All NaOCl/DR groups exhibited a significantly greater dissolution activity than that of NaOCl alone, with the mean weight loss ranging from 23.3 mg (40 wt%) to 24 mg (41 wt%). ID9% and ID15% significantly decreased the proteolytic activity of NaOCl. In most groups, the apical thirds of the root canals demonstrated a significantly heavier smear layer compared to the middle and coronal thirds. The most effective smear layer removal was observed after irrigation with NaOCl combined with EDTA or DR (all concentrations); however, in the NaOCl + EDTA and DR18% groups, it was accompanied by moderate to severe erosion. Irrigation with ID did not result in smear layer removal or dentin erosion. In conclusion, the smear layer removal and pulp dissolving effects of continuous chelation using etidronate were manufacturer/composition-dependent. DR9% combined with NaOCl demonstrated the most promising results.

Lipid radicals and oxidized cholesteryl esters in low- and high-density lipoproteins in patients with β-thalassemia: Effects of iron overload and iron chelation therapy

Iron overload results in lipid peroxidation (LPO) and the oxidative modification of circulating lipoproteins, which contributes to cardiovascular complications in patients with β-thalassemia. Investigating LPO may provide opportunities for the development of novel therapeutic strategies; however, the chemical pathways underlying iron overload-induced LPO in β-thalassemia lipoproteins remain unclear. In this study, we identified various species of lipid radicals (L•), the key mediators of LPO, and oxidized cholesteryl esters (oxCE) derived from the in vitro oxidation of major core lipids, cholesteryl linoleate (CE18:2) and cholesteryl arachidonate (CE20:4); the levels of these radical products in low-density lipoproteins (LDL) and high-density lipoproteins (HDL) were measured and compared between β-thalassemia patients and healthy subjects by using a specific fluorescent probe for L• with a liquid chromatography-tandem mass spectrometric method. Our results demonstrated that iron overload substantially decreased the levels of CE18:2 and CE20:4 substrates and α-tocopherol, resulting in higher levels of full-length and short-chain truncated L• and oxCE products. In particular, CE epoxyallyl radicals (•CE-O) were observed in the lipoproteins of β-thalassemia, revealing the pathological roles of iron overload in the progression of LPO. In addition, we found that intermission for two weeks of iron chelators can increase the production of these oxidized products; therefore, suggesting the beneficial effects of iron chelators in preventing LPO progression. In conclusion, our findings partly revealed the primary chemical pathway by which the LPO of circulating lipoproteins is influenced by iron overload and affected by iron chelation therapy. Moreover, we found that •CE + O shows potential as a sensitive biomarker for monitoring LPO in individuals with β-thalassemia.

Synthesis, performance and application of environmental protection scale inhibitorβ-CD-MA-SSS copolymer——in electric power industry

The issue of water scaling in the treatment of cooling water has become an imperative problem that should be solved urgently for the sake of safe operation in large-scale flexible DC converter stations. However, the coexistence of Ca2+ and Mg2+ in high content in this sort of pending raw water is quite hard to tackle. β-CD-MA-SSS, an eco-friendly ternary co-polymer antiscalant with good performance of inhibiting the formation of scale, was applied to address this conundrum in this paper. The efficacy of the antiscalant β-CD-MA-SSS was investigated in cooling water systems under the conditions of low hardness, low alkalinity, a temperature not exceeding 80 °C, and a pH range of 6–8. After optimization, this reagent dem onstrated an excellent scale inhibition rate up to 80% for both calcium carbonate and calcium-magnesium mixed scales. Scanning electron microscopy (SEM) analysis revealed a noticeable reduction in the size of CaCO3 particles when subjected to the action of β-CD-MA-SSS. It was postulated from FTIR analysis that nanoinpurity and chelation effects mainly contributed to the mixed scale inhibition. Further, the effect of β-CD-MA-SSS on the actual production wastewater was comprehensively evaluated from the technical, economic and environmental aspects.

Recent Advances on Regioselective C−H Borylation of Indoles

Borylated indoles are versatile building blocks for functional molecules, such as pharmaceutical and natural products. However, the C−H borylation regioselectivity of unprotected indoles with seven distinct sites has been a problem for a long time. Among the various synthetic approaches to borylated indoles, transition‐metal‐catalyzed, electrophilic C−H borylation and chelation effect directed C−H borylation are attractive methods because of their powerful ability to rapidly construct various C−H borylation of indoles. In this review, we highlight the developments in the C−H borylation regioselectivity of indole using these methods of C−H borylation over the last 20 years. With a focus on the mechanism of the C−H borylation of indole, further studies and developments of this field would be inspired in the future.

Effect of different chelators on the push-out bond strength of hydraulic cements in retrograde obturation.

This study examined the effect of ethylenediaminetetraacetic acid (EDTA) and etidronic acid (HEDP) in retrograde cavities on the bond strength of MTA Angelus and NeoPutty. Sixty-six teeth with single roots and canals were decoronated and enlarged up to F3 using the ProTaper Universal file system. After removing the apical 3 mm within the scope of endodontic surgery procedures, retrograde cavities were prepared with ultrasonic tips. The teeth were divided into three main groups according to the irrigation solution used: saline, 17% EDTA, and 9% HEDP. Following the irrigation of retrograde cavities, each main group was further divided into two subgroups in terms of using MTA Angelus and NeoPutty as retrograde filling materials. Bond strength values of hydraulic cements were measured by the push-out test. Fracture modes were examined under a stereo microscope. Two dentin sections from each group were examined under scanning electron microscopy (SEM) to observe dentinal tubules. Two-way ANOVA and post hoc Tukey tests were used to analyze the data. Irrigation solutions similarly affected the bond strength values of hydraulic cements (P=0.115). MTA Angelus showed significantly higher values than NeoPutty in all the solution groups (P=0.34). Adhesive and cohesive fracture modes were mostly observed in the MTA Angelus and NeoPutty groups, respectively. EDTA, HEDP, and saline had a similar effect on the bond strength of hydraulic cements. The higher bond values of MTA Angelus compared to NeoPutty could support its safe use in endodontic surgery procedures.

Research Progress in Starch-based Dye Adsorbents

Abstract: Starch is a typical environment-friendly biomass material and there are considerable quantities of reactive hydroxyl groups in the starch molecule chain. Modifications could introduce a large number of functional groups, which can bind some dyeing contaminants, thereby removing the dyes. According to the different modification methods, starch-based adsorbents can be divided into three categories that are aminated-modified starch, ionic-modified starch, and composite-modified starch. The preparation method, structure properties, and adsorption capacity of modified starch dye adsorbents have been reviewed in this article. It can be concluded that the adsorption property of adsorbents depends on different adsorption conditions and modification methods. The adsorption properties of the adsorbents have been found to be influenced by temperature, initial concentration of dyes, and pH value of solution. Amination modification can introduce amino or amine groups into the starch skeleton to enhance the chelation or electrostatic effect of the adsorbents on dyes. Ion modification can improve the ion exchange and electrostatic interaction between the adsorbents and the dye. Composite modification can improve specific surface area, pore size, adsorption site, and structural stability of the adsorbents. Future studies are required to focus on producing dye adsorbents with high adsorption performance, stable structure, recyclability, and degradability.

Influence of various ion chelators on mechanical, transport and microstructure properties of cement-based materials

Influence mechanism of various ion chelators on the mechanical, transport, and microstructure properties of cement-based materials was explored. The ion chelators included pentasodium diethylenetriamine pentaacetate, tetrasodium ethylenediaminetetraacetate, sodium hexametaphosphate and tetrasodium glutamate diacetate, with a dosage of 1% of the cement mass. The effect of ion chelators on the mechanical, transport, and pore structure properties was evaluated by compressive, sorptivity, and mercury intrusion porosimetry (MIP) tests. The composition and microstructure of hydration products were studied by scanning electron microscope (SEM) and X-ray diffractometer (XRD). Test results indicated that four ion chelators reduced the mechanical and transport properties, and increased the porosity of specimens at 3 d and 7 d. And four ion chelators improved the mechanical and transport properties, and reduced porosity at 28 d and 56 d. The fundamental reason for the differences in the basic properties of cement-based materials caused by the types of ion chelators is that different ion chelators possess various calcium chelating capacities and stability of calcium complexes, which leads to different impact on the complexation substitution reaction process. Moreover, compared to the stability of calcium complexes, the influence of calcium chelating ability on the basic properties of specimens is more significant in the early curing ages.

Fabrication of recoverable plant polyphenol-based surfactants for efficient removal of uranyl ions from skin and cotton fabric

With the increasing demand for uranium in the nuclear industry, the unintended uranium contamination of skin or clothing for individuals involved in nuclear activities has raised public health concerns. Herein, a plant polyphenol-based surfactant (sulfonated bayberry tannin surfactant, SBTS) was fabricated by modifying the hydrophobic groups in the sulfonated bayberry tannin (SBT) structure using a simple Friedel–Crafts alkylation reaction. The surfactant modified with tetradecane chloride showed superior foaming ability and emulsifying properties compared with SBT. The characterization of SBTS by FT-IR spectroscopy confirmed that hydrophobic chains were successfully grafted on SBT molecules via covalent bonds. As expected, SBTS could disperse in water under near-neutral pH condition, and showed good foaming and emulsifying properties. Moreover, the surfactant exhibited effective removal ability for UO22+-contaminated cotton fabric and skin in a broad application range, reaching a removal rate of 99 % for low amounts of UO22+, and even above 55 % for high UO22+ amounts. More importantly, SBTS after reacing with UO22+ could be easily separated from aqueous systems after standing for 60 min in acidic and neutral conditions, which is a favorable feature to avoid secondary pollution. In vitro cytotoxicity tests suggested that SBTS was much safer than commonly used synthetic surfactants. Based on XPS and FT-IR measurements, we propose a decontamination mechanism mainly originating from the chelation effect between the phenolic hydroxyl group of SBTS and UO22+. This study highlights the potential of plant tannin surfactants as effective materials for the removal of UO22+ from skin or clothing of individuals involved in various nuclear-related activities.

An artificial intelligence handheld sensor for direct reading of nickel ion and ethylenediaminetetraacetic acid in food samples using ratiometric fluorescence cellulose paper microfluidic chip

User-friendly in-field sensing protocol is crucial for the effective tracing of intended analytes under less-developed countries or resources-limited environments. Nevertheless, existing sensing strategies require professional technicians and expensive laboratory-based instrumentations, which are not capable for point-of-care on-site analyses. To address this issue, artificial intelligence handheld sensor has been designed for direct reading of Ni2+ and EDTA in food samples. The sensing platform incorporates smartphone with machine learning-driven application, 3D-printed handheld device, and cellulose paper microfluidic chip stained with ratiometric red-green-emission carbon dots (CDs). Intriguingly, Ni2+ introduction makes green fluorescent (FL) of CDs glow but red FL fade because of the coordination of Ni2+ with CDs verified by density functional theory (DFT), concurrently manifesting continuous FL colour transition from red to green. Subsequent addition of EDTA renders FL of CDs-Ni2+ recover owing to the capture of Ni2+ from CDs by EDTA based on strong chelation effect of EDTA on Ni2+ confirmed via DFT, accompanying with a noticeable colour returning from green to red. Inspired by above FL phenomena, CDs-based cellulose paper microfluidic chips are first fabricated to facilitate point-of-care testing of Ni2+ and EDTA. Designed fully-automatic handheld sensor is utilized to directly output Ni2+ and EDTA concentration in water, milk, spinach, bread, and shampoo based on wide linear ranges of 0–48 μM and 0–96 μM, and low limits of detection of 0.274 μM and 0.624 μM, respectively. The proposed protocol allows for speedy straightforward on-site determination of target analytes, which will trigger the development of automated and intelligent sensors in near future.

Asynchronous Synergetic Remediation Strategy for Cd-Contaminated Soil via Passivation and Phytoremediation Technology

Cadmium (Cd) contamination in soil has emerged as a significant challenge for agricultural production. Phytoremediation and passivation are key techniques for remediating Cd-contaminated soil. However, few studies have focused on the synergistic effects of these two techniques. In this work, the effectiveness of synergetic remediation strategies, both synchronous and asynchronous, utilizing passivation and phytoremediation techniques, was explored. The results of pot experiments and field experiments indicated that optimal remediation effects were obtained by asynchronous synergetic remediation, removing over 80% of bioavailable Cd within 14 days. Mechanistic studies conducted using XPS analysis, soil property analysis, and microbial diversity analysis confirmed that the chelation effect of SDD and soil pH value are the primary factors contributing to the effectiveness of both remediation strategies. In contrast, the variations in microbial populations are identified as the crucial factors influencing the varying outcomes of the two sequential remediation approaches. This research demonstrates that asynchronous synergistic remediation is a promising strategy for mitigating Cd contamination in soil.

Iron Chelation Therapy Elicits Innate Immune Control of Metastatic Ovarian Cancer.

Iron accumulation in tumors contributes to disease progression and chemoresistance. Although targeting this process can influence various hallmarks of cancer, the immunomodulatory effects of iron chelation in the tumor microenvironment are unknown. Here, we report that treatment with deferiprone, an FDA-approved iron chelator, unleashes innate immune responses that restrain ovarian cancer. Deferiprone reprogrammed ovarian cancer cells toward an immunostimulatory state characterized by the production of type-I IFN and overexpression of molecules that activate NK cells. Mechanistically, these effects were driven by innate sensing of mitochondrial DNA in the cytosol and concomitant activation of nuclear DNA damage responses triggered upon iron chelation. Deferiprone synergized with chemotherapy and prolonged the survival of mice with ovarian cancer by bolstering type-I IFN responses that drove NK cell-dependent control of metastatic disease. Hence, iron chelation may represent an alternative immunotherapeutic strategy for malignancies that are refractory to current T-cell-centric modalities. Significance: This study uncovers that targeting dysregulated iron accumulation in ovarian tumors represents a major therapeutic opportunity. Iron chelation therapy using an FDA-approved agent causes immunogenic stress responses in ovarian cancer cells that delay metastatic disease progression and enhance the effects of first-line chemotherapy. See related commentary by Bell and Zou, p. 1771.

Edetate Disodium–Based Chelation for Patients With a Previous Myocardial Infarction and Diabetes

In 2013, the Trial to Assess Chelation Therapy (TACT) reported that edetate disodium (EDTA)-based chelation significantly reduced cardiovascular disease (CVD) events by 18% in 1708 patients with a prior myocardial infarction (MI). To replicate the finding of TACT in individuals with diabetes and previous MI. A 2 × 2 factorial, double-masked, placebo-controlled, multicenter trial at 88 sites in the US and Canada, involving participants who were 50 years or older, had diabetes, and had experienced an MI at least 6 weeks before recruitment compared the effect of EDTA-based chelation vs placebo infusions on CVD events and compared the effect of high doses of oral multivitamins and minerals with oral placebo. This article reports on the chelation vs placebo infusion comparisons. Eligible participants were randomly assigned to 40 weekly infusions of an EDTA-based chelation solution or matching placebo and to twice daily oral, high-dose multivitamin and mineral supplements or matching placebo for 60 months. This article addresses the chelation study. The primary end point was the composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. Median follow-up was 48 months. Primary comparisons were made from patients who received at least 1 assigned infusion. Of the 959 participants (median age, 67 years [IQR, 60-72 years]; 27% females; 78% White, 10% Black, and 20% Hispanic), 483 received at least 1 chelation infusion and 476 at least 1 placebo infusion. A primary end point event occurred in 172 participants (35.6%) in the chelation group and in 170 (35.7%) in the placebo group (adjusted hazard ratio [HR], 0.93; 95% CI, 0.76-1.16; P = .53). The 5-year primary event cumulative incidence rates were 45.8% for the chelation group and 46.5% for the placebo group. CV death, MI, or stroke events occurred in 89 participants (18.4%) in the chelation group and in 94 (19.7%) in the placebo group (adjusted HR, 0.89; 95% CI, 0.66-1.19). Death from any cause occurred in 84 participants (17.4%) in the chelation group and in 84 (17.6%) in the placebo group (adjusted HR, 0.96; 95% CI, 0.71-1.30). Chelation reduced median blood lead levels from 9.03 μg/L at baseline to 3.46 μg/L at infusion 40 (P < .001). Corresponding levels in the placebo group were 9.3 μg/L and 8.7 μg/L, respectively. Despite effectively reducing blood lead levels, EDTA chelation was not effective in reducing cardiovascular events in stable patients with coronary artery disease who have diabetes and a history of MI. ClinicalTrials.gov Identifier: NCT02733185.