Chelating Research Articles

Immuno-PET Imaging of EGFR with 64Cu-NOTA Panitumumab in Subcutaneous and Metastatic Nonsmall Cell Lung Cancer Xenografts.

Objective: About 65-90% of nonsmall cell lung cancer (NSCLC) express the epithelial growth factor receptor (EGFR) as a transmembrane protein that is activated by binding of specific ligands, including epidermal growth factor and transforming growth factor α (TGFα). Identifying EGFR as an oncogene has led to the development of anticancer therapeutics directed against EGFR, including the full-length human IgG2 monoclonal antibody panitumumab. The main goal of the present study was to investigate 64Cu-labeled panitumumab with immuno-PET in subcutaneous and metastatic EGFR-positive NSCLC xenografts. Methods: Bifunctional chelating agent 2-S-(4-isothiocyanatobenzyl)-1,4,7-triazacyclo-nonane-1,4,7-triacetic acid (NOTA-NCS) was attached to panitumumab. The number of chelators per panitumumab was determined using matrix-assisted laser desorption/ionization (MALDI) mass spectroscopy. The incorporation efficiency of 64Cu into NOTA-panitumumab was measured by using radio-TLC. EGFR-expressing epithelial-like H1299-luc+ NSCLC cells were used for in vitro and in vivo experiments. Cell uptake of [64Cu]Cu-NOTA-panitumumab was measured in the presence and absence of panitumumab. Subcutaneous and metastatic H1299-luc tumor models were grown in male NSG mice. The presence of tumors at lung and metastatic sites was analyzed by [18F]FLT PET. Immuno-PET with [64Cu]Cu-NOTA-panitumumab was performed as static PET imaging at 2, 24, and 48 h postinjection in both tumor models. Proof-of-target was confirmed by blocking experiments with panitumumab. Detailed ex vivo biodistribution experiments were performed in both animal tumor models to confirm biodistribution profiles obtained by immuno-PET imaging. Results: MALDI analysis confirmed the attachment of ∼1.5 NOTA per antibody. Radiolabeling efficiency with [64Cu]CuCl2 was 93.8 ± 5.7% and a molar activity of 0.65 MBq/μg. Cellular uptake studies with [64Cu]Cu-NOTA-panitumumab in H1299 cells demonstrated increasing uptake over time, reaching 29.1 ± 2.9% radioactivity(Bq)/mg protein (n = 3) and plateauing at 45 min. Addition of 25 μg of panitumumab reduced radioligand uptake to 1.22 ± 0.06% radioactivity/mg protein (n = 3). PET imaging revealed high uptake of [64Cu]Cu-NOTA-panitumumab in subcutaneous tumors: Standardized uptake values (SUV)mean reached 4.70 ± 0.42 and 5.37 ± 0.40 (n = 5) after 24 and 48 h postinjection, respectively. Administration of 1 mg panitumumab reduced tumor uptake significantly to 1.94 ± 0.22 and 1.66 ± 0.08 (n = 4; p < 0.001). In the metastatic model, the following SUVmean were analyzed from liver and lung lesions: 5.55 ± 0.34 and 6.28 ± 0.46 (both n = 23 lesions from 6 mice) after 24 and 48 h postinjection, which was also significantly reduced to 2.53 ± 0.39 and 2.31 ± 0.15 (both n = 16 lesions from 4 mice; p < 0.001) after injection of 1 mg panitumumab. Detailed ex vivo biodistribution confirmed immuno-PET analysis in both models. Panitumumab reduced radioactivity uptake into subcutaneous tumors from 11.01 ± 0.72 (n = 4) to 3.67 ± 0.33% ID/g (n = 5; p < 0.001), and in metastatic liver lesions from 29.44 ± 8.14 (n = 4) to 8.35 ± 1.30% ID/g (n = 5; p < 0.001), respectively. Conclusions: [64Cu]Cu-NOTA-panitumumab was successfully used for immuno-PET imaging of EGFR-expressing subcutaneous and metastatic NSCLC tumors. This result represents the basis for developing radiotheranostics for targeting EGFR in cancers and for selecting the right patients for the right treatment at the right time.

Emerging insights into ferroptosis in cholangiocarcinoma (Review).

Cholangiocarcinoma (CCA) is a malignant tumor that arises within the biliary system, which exhibits a progressively increasing incidence and a poor patient prognosis. A thorough understanding of the molecular pathogenesis that drives the progression of CCA is essential for the development of effective molecular target therapeutic approaches. Ferroptosis is driven by excessive iron accumulation and catalysis, lipid peroxidation and the failure of antioxidant defense systems. Key molecular targets of iron metabolism, lipid metabolism and antioxidant defense systems involve molecules such as transferrin receptor, ACSL4 and GPX4, respectively. Inhibitors of ferroptosis include ferrostatin-1, liproxstatin-1, vitamin E and coenzyme Q10. By contrast, compounds such as erastin, RSL3 and FIN56 have been identified as inducers of ferroptosis. Ferroptosis serves a notable role in the onset and progression of CCA. CCA cells exhibit high sensitivity to ferroptosis and aberrant iron metabolism in these cells increases oxidative stress and iron accumulation. The induction of ferroptosis markedly reduces the ability of CCA cells to proliferate and migrate. Certain ferroptosis agonists, such as RSL3 and erastin, cause lipid peroxide build up and GPX4 inhibition to induce ferroptosis in CCA cells. Current serological markers, such as CA-199, have low specificity and cause difficulties in the diagnosis of CCA. However, novel techniques, such as non-invasive liquid biopsy and assays for oxidative stress markers and double-cortin-like kinase 1, could improve diagnostic accuracy. CCA is primarily treated with surgery and chemotherapy. A close association between the progression of CCA with ferroptosis mechanisms and related regulatory pathways has been demonstrated. Therefore, it could be suggested that multi-targeted therapeutic approaches, such as ferroptosis inducers, iron chelating agents and novel modulators such as YL-939, may improve treatment efficacy. Iron death-related genes, such as GPX4, that are highly expressed in CCA and are associated with a poor prognosis for patients may represent potential prognostic markers for CCA. The present review focused on molecular targets such as p53 and ACSL4, the process of targeted medications in combination with PDT in CCA and the pathways of lipid peroxidation, the Xc-system and GSH-GPX4 in ferroptosis. The present review thus offered novel perspectives to improve the current understanding of CCA.

Phytoremediation of lead polluted mine soil by synergistic effect of chelating agents and nitrogen in hemp

Industrial hemp is a valuable fibrous plant with high biomass production for it can survive under variable environmental stresses including heavy metals and is used in a wide range of products. This research work aimed at determining the growth potential of industrial hemp (Cannabis sativa) developed on lead (Pb) contaminated mine soils using various chelating agents viz., ethylenediaminedisuccinic acid (EDDS), ethylenediaminetetraacetic acid (EDTA), citric acid (CA) and nitrilotriacetic acid (NTA) under various concentrations of nitrogen (N) fertilizer such as 0 (control), 50, 150, 250 and 350 kg ha−1. Results indicated that the synergistic effect of chelating agents and rising concentrations of N fertilizer resulted in a linear increase in hemp growth and dry biomass. The chelating agent and N mediated showed better response in the photosynthetic, antioxidative, and osmolytic potential of hemp as compared with control. The concentration of N and Pb plants showed a differential response such as N accumulation was maximum in plant leaf and shoot portions as compared to the roots. In contrast, Pb enrichment was higher in the roots than in the plant’s leaves and stems when exposed to varying concentrations of N fertilizer and chelating agents in the soil environment. Biomobilizaiton of Pb in the plant continuum enhanced with the rising N fertilizer levels in the soil. The EDTA showed better phytoextraction potential as compared with the rest of the chelating agents. Hence, findings suggest that the synergistic application of chelating agents and N fertilizer is a far more effective technique that increases the bioavailability of Pb for phytoextraction and decreases Pb-induced oxidative injuries by restricting Pb uptake.

A phase transition coordinated monoclinic Fe-based Prussian blue for high-performance sodium-ion battery cathode

Prussian blue analogs (PBAs) are ideal cathode materials for sodium-ion batteries (SIBs) owing to their cost-effectiveness, good low-temperature performance, and facile synthesis process. Nevertheless, their actual capacity and cycling stability limit practical application. Herein, a new chelating agent, sodium tartrate, is proposed to synthesize high-quality Fe-based Prussian blue (HQ-NFF) with enhanced Na content and a stable structure through chelation effect-assisted co-precipitation. The crystal structure of HQ-NFF undergoes a phase transition to a Na-rich monoclinic phase after full discharge, leading to improved capacity and cycling stability. The HQ-NFF cathode exhibits an ultra-high capacity of 160.8 mAh g−1 and a capacity of 146.1 mAh g−1 at 2 C, with a capacity retention of 75.3 % after 150 cycles. Moreover, a 3D-printed HQ-NFF cathode with an areal loading of 7.88 mg cm−2, delivers a high areal capacity of 0.969 mAh cm−2 and good rate capability.

Investigating the Interactive Effect of Arbuscular Mycorrhizal Fungi and Different Chelating Agents (EDTA and DTPA) with Different Plant Species on Phytoremediation of Contaminated Soil

Heavy metal (HM) contamination in soil poses a severe environmental threat, jeopardizing ecosystem health and potentially entering the food chain through plant uptake. Phytoremediation, a bioremediation technique utilizing plants to remove or immobilize contaminants, offers a sustainable and eco-friendly solution for HM remediation. This study investigated the interactive effects of arbuscular mycorrhizal fungi (AMF) and chelating agents (EDTA and DTPA) on the growth of maize (Zea mays L.) and alfalfa (Medicago sativa L.) cultivated in metal-contaminated soil and their impact on HM uptake by these plants. The findings revealed that AMF and chelating agents have complex interactive effects on plant growth and metal accumulation. Maize (Zea mays L.) shoot dry matter increased with AMF and chelating agents at lower concentrations. Both plants generally showed a significant (p ≤ 0.05) increase in shoot dry matter with amendments, with AMF × EDTA (10 mmol/kg) being the most effective for alfalfa. DTPA and EDTA generally reduced the DTPA-extractable metals in soil, suggesting potential for metal removal. However, the effects of AMF on metal availability were variable. Metal concentrations in maize (Zea mays L.) shoots increased with increasing DTPA and EDTA concentrations, while the effects of AMF were more complex. The alfalfa shoot metal content showed varied responses, with EDTA (5 mmol/kg) effectively reducing the metal uptake. In general, treatments involving chelating agents (DTPA and EDTA) tend to result in higher bioaccumulation factor (BF) values compared to the non-treated controls for most HMs in both plant species. Mycorrhizal fungi (AMF) treatment alone or in combination with chelating agents also showed that varied effects on HM uptake in both the alfalfa and maize treatments with chelating agents, especially at higher concentrations, generally promoted the greater translocation of HMs in both plant species. Both alfalfa and maize responded differently to treatments, with some treatments showing higher translocation factor (TF) values for certain HMs in one species compared to the other. Mycorrhizal fungi (AMF) treatment alone or in combination with chelating agents also showed varied effects on HM uptake and translocation in both alfalfa and maize. Further research is required to optimize remediation strategies that balance plant health and metal mobilization.

The influence of Fe2+ on the self-assembly of a bipyridine containing homopolymer: From bowl-shaped nanoparticles to vesicles

Metal ion coordination has critical influence on the self-assembly behavior of amphiphilic polymers and the morphology of the obtained assemblies. Herein, an amphiphilic homopolymer with 2,2′-bipyridine (BPy) as side chain is synthesized (noted as PBPyAA), which can self-assemble into bowl-shaped nanoparticles (BNPs) in tetrahydrofuran (THF)/water. Taking advantage of the coordination interaction between BPy and metal ions, Fe2+ is chosen to regulate the self-assembly behavior and the morphology of the assemblies of PBPyAA in two pathways. (Ⅰ) The aqueous solution of Fe2+ with various concentrations is added to the THF solution of PBPyAA during self-assembly. (Ⅱ) Fe2+ is added into the THF solution of PBPyAA before self-assembly, followed by the addition of deionized water to promote the self-assembly. The results show that the pathway Ⅰ facilitates the coordination of BPy and Fe2+. With the increase of the concentration of Fe2+ aqueous solution, the coordination efficiency of BPy increases from 0.419 % to 7.789 %, leading to the transformation of BNPs to vesicles. Though the coordination efficiency of BPy also increases with the concentration of Fe2+ in pathway Ⅱ, which is still quite low of 0.274 % to 0.366 %, and the morphology of the BNPs barely changes. In addition, ethylene diamine tetraacetic acid (EDTA), a strong chelating agent, is also added to promote the competitive complexation with BPy, resulting in the dissociation of BPy and Fe2+ and the reversible transformation from vesicles to BNPs. Overall, the effect of Fe2+ coordination on the self-assembly behavior of PBPyAA in two pathways is investigated and the reversible transformation of BNPs to vesicles is also achieved.

Controlling Chelation and Esterification in Pechini Synthesis for Enhancing Chemical Looping Steam Methane Reforming using LaFeO3 Perovskite.

The properties of an oxygen carrier, such as crystalline structure, textural properties, and surface chemical species, significantly influence the redox performance in thermochemical redox applications. This study presents the synthesis of various lanthanum orthoferrite (LaFeO3) perovskites by adjusting Pechini synthesis parameters, including chelating agent ratio, calcination temperature, and solution pH. A larger surface area emerged as a dominant factor contributing to improved redox performance. The porosity of the polyester resin proves crucial in achieving a large surface area and a small particle size for the oxygen carrier. This goal could be attained by controlling the pH of the precursor solution. A low degree of chelation or precipitation may lead to uneven cation distribution, resulting in the enrichment of trace hydroxide impurities. These impurities can suppress the reducibility of particles during the looping experiment. Various investigations, using XRD, XPS, XAS, SEM, and N2 physisorption, revealed that porosity and crystallinity can be controlled by altering the synthesis parameters.

The Neuroprotective Effect of Calotropis procera Against Toxicity of Mercury Chloride

Background: Central nervous system intoxication can result from exposure to various toxins, including mercury chloride. Although several chelating agents are available for mercury chloride detoxification, their efficacy can diminish over time. Calotropis procera, a medicinal plant, has shown potential as a protective agent against mercury chloride-induced brain damage. This study aims to evaluate the protective effects of Calotropis procera in mitigating mercury chloride toxicity. Experimental animal design: This study investigates the protective effects of Calotropis procera against mercury chloride toxicity in Wistar albino rats. A total of 36 rats, comprising both males and females, were housed under controlled laboratory conditions and divided into two main groups based on five animals. Each group was further subdivided into five subgroups: a control group, a group treated with Calotropis procera, a group treated with mercury chloride, a group treated with both mercury chloride and Calotropis procera and a group receiving Calotropis procera alongside mercury chloride. Treatments were administered for 20 days. After the treatment period, the rats were euthanised, and brain tissues were collected for histopathological analysis. After the brain tissues were fixed in 10% saline-buffered formalin, they were processed through a series of ascending grades of ethanol to dehydrate them. The tissues were then cleared in xylene and embedded in paraffin. The paraffin-embedded brains were treated three times with pure paraffin to ensure proper infiltration and were subsequently moulded into blocks. Sections of 5 µm thickness were prepared using a Leica microtome and stained with Haematoxylin and Eosin (H&amp;E) for histopathological examination. The study adhered to ethical guidelines and was approved by the relevant regulatory body. The results of this study demonstrated that mercury chloride caused significant cerebral toxicity, manifesting as inflammation and pyknosis of the nuclei. Calotropis procera reduced mercury toxicity and preserved the nuclei in male rats. In female rats, Calotropis procera completely preserved the brain tissue.

Challenges in diagnosis and treatment of cystinuria patients with Urolithiasis: multicenter patient centered study.

Cystinuria represents a rare cause of urolithiasis, accounting for 1% of all cases. However, it poses unique challenges in diagnosis and management. This study aimed to examine the challenges of managing cystine stones from the perspective of cystinuria patients. Following ethical approval, we reviewed the medical records of cystine stone patients treated at four tertiary centers from 2016 to 2021 and surveyed them on their perceptions of cystinuria. It included questions about demographic characteristics, herbal treatments, pain management, online engagement, disease outcomes, and cystinuria-related fears. The study included 28 adults with cystinuria nephrolithiasis, with a mean age of 30.5 years. Of these, 78.6% had consanguineous parents, and the first stone episode occurred at a mean of 14.82 years age. Family history of Cystinuria was encountered in 82.1%. Cystinuria was diagnosed after a mean of 6.43 years from the first stone episode, and stone analysis was performed in 22/28 after a mean of 3.86 years from the first stone episode. Only 17 patients (60.8%) underwent metabolic evaluation for kidney stones. Regarding non-surgical treatments, 13 (46.5%) patients received alkalinization medication, and only 10 (35.7%) were prescribed chelating agent therapy. Additionally, 50% of patients took herbal remedies. The diagnosis of cystinuria is often delayed, leading to a delay in receiving medical treatment (alkalinization and chelating agents) and poor health education and counseling. Thus, referring cystinuria patients to tertiary hospitals and providing a multidisciplinary approach might decrease the morbidity of the disease and enhance their well-being.

A Novel Bifunctional Chelating Agent for Tyrosine-Specific Radiolabeling of Peptides and Proteins.

Site-specific radiolabeling is utilized for the development of antibody- or peptide-based radiotheranostic agents. Although tyrosine can be exploited as one of the target residues for site-specific radiolabeling of peptides and proteins, a tyrosine-specific radiolabeling method has not been established. In this study, we newly designed and synthesized a novel bifunctional chelating agent, TBD-DO3A, consisting of a triazabutadiene (TBD) scaffold and metal chelator, 1,4,7,10-tetraazacyclododecane 1,4,7-triacetic acid (DO3A). Conjugation of TBD-DO3A with Ac-Tyr-NHMe followed by 111In-labeling afforded [111In]In-Tyr-DO3A, which showed high-level stability in mouse plasma. Then, we selected the tyrosine-containing cyclic peptide c(RGDyK) as a model ligand and synthesized [111In]In-RYD. [111/natIn]In-RYD showed in vitro binding properties for integrin αvβ3 equivalent to those of [111/natIn]In-RKD, a lysine residue-labeled control compound. In in vivo biodistribution and SPECT/CT imaging studies using U87MG/PC-3 tumor-bearing mice, [111In]In-RYD and [111In]In-RKD were selectively accumulated and facilitated U87MG tumor visualization at 24 h postinjection. These results indicate that TBD-DO3A has fundamental properties as a bifunctional chelator for tyrosine-specific radiolabeling of peptides and proteins.

Optimizing deposition parameters and characterizing TiO2 thin films for future memristor applications

Titanium dioxide (TiO2) thin films were deposited on glass substrates using Spray Pyrolysis technique, with variations in multiple deposition parameters. The molarity of the precursor was altered within a small range from 0.09 M–0.15 M. The deposition temperature was systematically adjusted from 200 °C to 400 °C while the ratio between precursor and chelating agent varied between 1:1,1:2 and 1:3. The thickness of TiO2 films were found to be in the range of 216 nm to 14.9 μm. Structural analysis conducted by XRD confirmed the formation of anatase TiO2 thin films. Optical studies using UV-Visible spectrophotometer determined the absorption and indirect bandgap ranging from 299 nm to 326 nm and 3.08 eV to 3.44 eV respectively. Electrical studies carried out evaluated the leakage currents and DC resistivity for all individual films with the input voltage applied from ± 0.5 V to ± 5V. Impedance studies were conducted by varying input voltages from 0.2V–3V for each film, so as to examine the resultant impedance, dielectric constant, dielectric loss, conductivity, admittance and modulus spectra. The obtained results were analysed to optimise the deposition parameters for designing future memristors with specific individual or combined characteristics, such as high ON/OFF, switching speed, endurance and retention.

An Interdisciplinary Assessment of the Impact of Emerging Contaminants on Groundwater from Wastewater Containing Disodium EDTA

In recent years, there has been a surge in interest concerning emerging contaminants, also known as contaminants of emerging concern (CECs), due to their presence in environmental matrices. Despite lacking regulation, these chemicals pose potential health and environmental safety risks. Disodium EDTA, a widely utilized chelating agent, has raised concerns regarding its environmental impact. The present work aimed to verify the presence of Disodium EDTA at the exit of eight wastewater treatment plants discharging into some losing streams flowing within a large alluvial aquifer. Conducted in the Province of Parma (Northern Italy), the research employs a multidisciplinary approach, incorporating geological, hydrogeological, chemical, and microbial community analyses. Following a territorial analysis to assess industries in the region, through the use of ATECO codes (a classification system for economic activities), the study investigated the concentration of Disodium EDTA in effluents from eight diverse wastewater treatment plants, noting that all discharges originate from an activated sludge treatment plant, released into surface water courses feeding the alluvial aquifer. Results revealed detectable levels of Disodium EDTA in all samples, indicating its persistence post-treatment. Concentrations ranged from 80 to 980 µg/L, highlighting the need for further research on its environmental fate and potential mitigation strategies. Additionally, the microbial communities naturally occurring in shallow groundwater were analyzed from a hydrogeological perspective. The widespread presence of a bacterial community predominantly composed of aerobic bacteria further confirmed that the studied aquifer is diffusely unconfined or semi-confined and/or diffusely fed by surface water sources. Furthermore, the presence of fecal bacteria served as a marker of diffuse leakage from sewage networks, which contain pre-treated wastewater. Although concentrations of Disodium EDTA above the instrumental quantification limit have not been found in groundwater to date, this research highlights the significant vulnerability of aquifers to Disodium EDTA. It reveals the critical link between surface waters, which receive treated wastewaters impacted by Disodium EDTA, and groundwater, emphasizing how this connection can expose aquifers to potential contamination. At this stage of the research, dilution of wastewaters in surface- and groundwater, as well as hydrodynamic dispersion within the alluvial aquifer, seem to be the main factors influencing the decrease in Disodium EDTA concentration in the subsurface below the actual quantification limit. Consequently, there is a pressing need to enhance methodologies to lower the instrumental quantification limit within aqueous matrices. In a broader context, urgent measures are needed to address the risk of diffuse transport of CECs contaminants like Disodium EDTA and safeguard the integrity of surface and groundwater resources, which are essential for sustaining ecosystems and human health.

Synthesis of an Ethylenediaminetetraacetic Acid-like Ligand Based on Sucrose Scaffold and Complexation and Proton Relaxivity Studies of Its Gadolinium(III) Complex in Solution.

Sucrose constitutes a non-toxic, biodegradable, low-cost and readily available natural product. To expand its utility, we developed total synthesis for a ligand based on a sucrose scaffold for potential use as a metal chelation agent. The designed target (compound 2) has a metal-chelating functionality at both the C-6 and C-6' positions, which can provide a first coordination sphere of eight valencies. The designed total synthesis was highly efficient. To demonstrate the utility of the ligand, we studied its complexation with Gd(III). Using potentiometric titration and high-resolution mass spectrometry, we confirmed the formation of a 1:1 complex with Gd(III), which has a respectable formation constant of ~1013.4. Further NMR relaxivity studies show that the Gd(III) complex has a relaxivity (r1) of 7.6958 mmol-1 s-1.

B-229 Extraction-free Nucleic Acid Sample Preparation from Inhibitor Rich Samples via Hyperbaric Heating

Abstract Background Extraction-based nucleic acid sample preparation for PCR is limited by long processing times, liquid transfers, cost, and storage requirements. Extraction-free approaches enable streamlined sample prep but are severely impacted by inhibitors present in biological sample matrices. We previously reported the use of Hyperbaric Heating (HBH) for effective organism lysis and demonstrate here its effectiveness to prepare nucleic acids for PCR from various inhibitor-rich sample matrix types. Methods HBH exposes the sample to high temperature/high pressure environment for a short duration. This process effectively lyses organisms and denatures inhibitors within seconds. Samples are sealed within a pressure-tight metallic vessel, then rapidly heated using magnetic induction. Within the sealed metallic vessel, vaporization of the aqueous sample raises the internal pressure, enabling an internal temperature higher than 100°C. Proprietary sample processing beads containing chelating agents and other proteins protect nucleic acids from fragmentation during heating. Results The efficacy of HBH for PCR amplification was tested against commercial kits and extraction-free methods. HBH treatment of nasal swab samples spiked with inactivated SARS-CoV-2 elicited detection down to 125 viral copies/mL. Viruses such as RSV and Influenza spiked in nasal swab samples demonstrated comparable PCR results as extraction prepped samples. HBH treatment of microbe samples, including Candida albicans spiked in urine and Bacillus subtilis spiked in serum, had comparable PCR threshold cycles as microbe specific DNA extraction methods (Table 1). Conclusions HBH is a generalizable extraction-free nucleic acid sample prep technology affording detection capabilities comparable to commercial sample prep methods. We demonstrated the use of HBH sample prep for detection of several infectious microorganisms in common biological matrices (nasal swab, serum, urine) without additional sample purification. With its ease of use, speed, and lower cost, HBH will be a key tool in applications where nucleic acid amplification is pivotal for diagnostic and research use.

Supercritical carbon dioxide chelation extraction of heavy metal ions from drilling fluid waste: Experiment and simulation

This study evaluates the application of supercritical carbon dioxide chelation extraction technology for treating heavy metal ions (Zn2+ and Cr3+) in drilling fluid waste. Through a combination of experimental and molecular dynamics simulation methods, the influence of extraction parameters (temperature, pressure, duration, and chelating agents) on the extraction efficiency are investigated. Findings show that increased duration and pressure significantly improve extraction efficiency, while temperature has a complex effect, initially increasing efficiency but plateauing and slightly decreasing at higher temperatures. The optimum extraction condition with pressure of 220 bar, temperature 348.15 K and an extraction duration of 70 min using ethylene diamine tetraacetic acid (EDTA) as the chelating agent has been determined. Importantly, molecular simulation analysis revealed that citric acid outperforms EDTA in terms of Zn2+ and Cr3+ aggregation by forming larger aggregates with greater numbers of molecules while reducing overall aggregate count. Furthermore, optimization of extraction pressure in the EDTA system shows potential benefits. These results suggest that supercritical carbon dioxide chelation extraction technology has strong potential for environmentally friendly and reliable waste management in the drilling industry. This study represents a significant step forward in developing sustainable solutions for heavy metal removal from drilling fluid waste.

Micellar Nanogels from Alginate-Based Diblock Copolysaccharides.

Alginates are marine polysaccharides known for their ability to selectively bind calcium ions and form hydrogels. They are widely used in biomedical applications but are challenging to produce as nanogels. Here we introduce a self-assembly route to create stable alginate-based nanogels under near-equilibrium conditions. Guluronate (G) blocks, which interact with divalent cations such as Ca2+, Ba2+, and Sr2+, were extracted from alginates and covalently linked through their reducing end to the reducing end of dextran (Dex) chains, forming linear block copolymers that self-assemble into micellar nanogels with a core-corona structure in the presence of these ions. Real-time dynamic light scattering (DLS) and small-angle neutron scattering (SANS) were used to study the self-assembly mechanism of the copolymer during dialysis against divalent ions. For the G12-b-Dex51 copolymer, we achieved spherical micelles with an 8 nm radius and an aggregation number of around 20. Although the type of divalent cation affected micelle stability, it did not influence their size. Micellar nanogels are dynamic structures, capable of ion exchange, and can disassemble with chelating agents like ethylenediamine tetraacetic acid (EDTA).

Development and Application of a Chelating Acid for Water Injection Wells of Chang 6 Reservoir of An-Sai Oilfield

Abstract Ansai oilfield is a typical low permeability, low pressure, low yield and serious heterogeneity oilfield. Chang 6 play of Triassic YanChang Formation is a typical ultra-low permeability reservoir. The average porosity of the reservoir is 10 % ~ 14 %, and the average permeability is (0.2 ~ 4.0) × 10−3 μm2. The absolute content of clay minerals in the reservoir is relatively high, with an average content of 18.61 %. The main components are kaolinite, chlorite, illite and illite/montmorillonite interlayer. Due to the reservoir blockage caused by scaling, water sensitivity and formation particle migration in the process of water injection, high injection pressure and under injection wells is increasing dramatically. In view of the above challenges, a fit-for-purpose acid, which contains organic acids and chelating agents, was developed for injection pressure reduction and injection enhancement. It has the characteristics of strong dissolution, good retarding and corrosion inhibition performance. Corrosion rate is 0.5632 g / (m2·h) for J55 steel in 24h, and the core permeability increases by 74.57 % after acid flooding. It has been applied in field test of 3 wells in Chang 6 layer of Ansai oilfield since March 2024. The average daily injection volume increased by 37.87 %, and the validity period was more than 180 days.

Pediatric Lead Chelation Managed During Critical Medication Shortages: Case Report and Literature Review.

Lead poisoning in children has the potential for devastating neurodevelopmental consequences. There is significant socioeconomic disparity in children with lead poisoning. Specific lead chelation regimens have been approved for children by the US Food and Drug Administration, however in the United States, there has been a recent national shortage of the primary therapy, edetate calcium disodium (CaNa2 EDTA). This case report presents a 23-month-old child with severe symptomatic lead poisoning during a national shortage of CaNa2 EDTA to highlight the need for advocacy regarding critical medication shortages, especially for antidote therapy. The infant's initial blood lead level was 364 mcg/dL and he received a continuous infusion of CaNa2 EDTA (1000 mg/m2/day), as well as dimercaprol (4 mg/kg intramuscularly every 4 hours). The supply of CaNa2 EDTA was exhausted on day 3 of therapy so he was transitioned to enteral succimer monotherapy. Initial parenteral therapy of 72 hours achieved a lead level of 72 mcg/dL; he then completed his enteral course of succimer along with environmental mitigation. However, elevated blood lead levels persisted and he subsequently required 3 more courses of enteral succimer, and he continues to have detectable blood lead levels 2 years after initial presentation. In the face of medication shortages including CaNa2 EDTA, and now also dimercaprol, clinicians must create and study alternative chelation therapy regimens for pediatric lead toxicity. Furthermore, public policy initiatives, including the development of a national supply stockpile of chelation agents, must be created in order to minimize supply chain disruption and ensure adequate and equitable antidote therapy for lead poisoning outbreaks.

An Overview of Structural Framework and Classification of Theranostic Radiopharmaceuticals

AbstractRadiopharmaceuticals constitute the backbone of nuclear medicine research and have been commonly used in diagnostic imaging and radionuclide therapy. In the past, there has been a strong emphasis on the meticulous design and development of radiotheranostics for targeted molecular imaging and therapy of different types of tumors. Theranostic radiopharmaceuticals offer synergistic advantages of simultaneous molecular imaging and radionuclide therapy all in one molecule. Owing to their successful pre‐clinical and clinical applications, many new theranostic radiopharmaceuticals have been explored in recent years. This review aims to provide a comprehensive overview of the design and the structural framework of theranostic radiopharmaceuticals. In this review, we have primarily focused on the different types of chelating agents, linkers, and radionuclides used for the development of potential radiotheranostics. In addition, this review also summarizes the classification and the different categories of theranostic radiopharmaceuticals such as molecular radiotheranostics and nano‐radiotheranostics along with their pre‐clinical and clinical theranostic applications. The recent developments and the theranostic applications of small molecule‐based radiotheranostics, antibody‐based radiotheranostics, peptide‐based radiotheranostics, and nanoparticle‐based radiotheranostics have also been reviewed for inspiring research efforts towards the development of efficient radiotheranostics.

Bio-Inspired Fluorescent Calcium Sulfate for the Conservation of Gypsum Plasterwork.

In this work, the potential of bio-inspired strategies for the synthesis of calcium sulfate (CaSO4·nH2O) materials for heritage conservation is explored. For this, a nonclassical multi-step crystallization mechanism to understand the effect of calcein- a fluorescent chelating agent with a high affinity for divalent cations- on the nucleation and growth of calcium sulfate phases is proposed. Moving from the nano- to the macro-scale, this strategy sets the basis for the design and production of fluorescent nano-bassanite (NB-C; CaSO4·0.5H2O), with application as a fully compatible consolidant for the conservation of historic plasterwork. Once applied to gypsum (CaSO4·2H2O) plaster specimens, cementation upon hydration of nano-bassanite results in a significant increase in mechanical strength, while intracrystalline occlusion of calcein in newly-formed gypsum cement improves its weathering resistance. Furthermore, under UV irradiation, the luminescence produced by calcein molecules occluded in gypsum crystals formed upon nano-bassanite hydration allows the easy identification of the newly deposited consolidant within the treated gypsum plaster without altering the substrate's appearance.