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1.
J Air Waste Manag Assoc ; 74(3): 192-205, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38329723

RESUMO

Undersized fraction from aged municipal solid waste (UFAMSW), as a kind of soil-like material, has been proved effective in providing a large amount of organic matter and nutrients for soil and plants. The characteristics and effectiveness of heavy metal pollution removal in UFAMSW attracted tremendous research interest from scientists recently. In this study, the heavy metal removal efficiencies and bioavailability of washing on contaminated UFAMSW were evaluated with three washing reagents including ethylene diamine tetra acetic acid (EDTA), citric acid (CA), and humic acid (HA). The effects of chelating agent concentration, pH, and washing time on metal removal were investigated and response surface methodology (RSM) was employed to optimize the washing conditions. The results indicated that the removal efficiencies of Cu, Zn, and Mn could be 53.68%, 52.12%, and 30.63% by EDTA/HA washing and 42.36%, 39.67% and 28.49% by CA/HA washing, respectively. The European Community Bureau of Reference (BCR) sequential extraction was applied to analyze the fraction change of heavy metals in UFAMSW before and after washing, and it was found that chelating agent combined with HA could contribute to the removal of the exchangeable fraction. Physical and chemical properties of UFAMSW were improved to some extent after washing with mixed HA and chelating agent and could achieve the quality standard of landscape gardening soil. Accordingly, the mixture of HA and other chelating agents could be a promising washing process for preparation of landscape gardening soil using UFAMSW.Implications: Our manuscript studies the removal of heavy metals from the contaminated undersized fraction from aged municipal solid waste (UFAMSW). UFAMSW, as a kind of soil-like material, has been proved effective in providing a large amount of organic matter and nutrients for soil and plants however often limited by heavy metal pollution. The UFAMSW used in this experiment was collected after the excavation and screening-sorting of aged refuse from Changshankou Domestic Waste Sanitary Landfill in Wuhan City, Hubei Province, Southern China. This study investigated the effects of EDTA, CA, HA, mixed EDTA/HA, and mixed CA/HA washing on heavy metal removal (Cu, Zn, and Mn), bioavailability of residual heavy metal and properties. The effects of chelating agent concentration, pH, and washing time on metal removal were investigated and then response surface methodology was employed to optimize the washing conditions. The results showed that washing by CA/HA and EDTA/HA, had a higher removal efficiency of heavy metals (Cu, Zn, and Mn) in UFAMSW compared to single HA. Meanwhile, HA has a higher removal for exchangeable fraction of heavy metals, the exchangeable concentration of Cu, Zn, and Mn in CA/HA and EDTA/HA washed UFAMSW were lower compared with UFAMSW washed by single CA and EDTA. Thus, mixing HA with EDTA or CA makes a less risk to environmental and the removal efficiency is acceptable. Additionally, CA/HA and EDTA/HA washing tend to improve soil physicochemical properties and soil fertility. Thus, mixing HA with different washing agent are potential methods for preparation of landscape gardening soil using UFAMSW.


Assuntos
Metais Pesados , Poluentes do Solo , Ácido Edético/química , Substâncias Húmicas , Solo/química , Ácido Acético , Ácido Cítrico/química , Jardinagem , Resíduos Sólidos , Poluentes do Solo/análise , Quelantes/química , Metais Pesados/análise
2.
Environ Monit Assess ; 195(12): 1526, 2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-37996714

RESUMO

Chemically assisted phytoremediation is suggested as an effective approach to amplify the metal-remediating potential of hyperaccumulators. The current study assessed the efficiency of two biodegradable chelants (S,S-ethylenediamine disuccinic acid, EDDS; nitrilotriacetic acid, NTA) in enhancing the remediation of Cd by Coronopus didymus (Brassicaceae). C. didymus growing in Cd-contaminated soil (35-175 mg kg-1 soil) showed increased growth and biomass due to the hormesis effect, and chelant supplementation further increased growth, biomass, and Cd accumulation. A significant interaction with chelants and different Cd concentrations was observed, except for Cd content in roots and Cd content in leaves, which exhibited a non-significant interaction with chelant addition. The effect of the NTA amendment on the root dry biomass and shoot dry biomass was more pronounced than EDDS at all the Cd treatments. Upon addition of EDDS and NTA, bio-concentration factor values were enhanced by ~184-205 and ~ 199-208, respectively. The tolerance index of root and shoot increased over the control upon the addition of chelants, with NTA being better than EDDS. With chelant supplementation, bio-accumulation coefficient values were in the order Cd35 + NTA (~163%) > Cd105 + NTA (~137%) > Cd35 + EDDS (~89%) > Cd175 + NTA (~85%) > Cd105 + EDDS (~62%) > Cd175 + EDDS (~40%). The translocation factor correlated positively (r ≥ 0.8) with tolerance index and Cd accumulation in different plant parts. The study demonstrated that chelant supplementation enhanced Cd-remediation efficiency in C. didymus as depicted by improved plant growth and metal accumulation, and NTA was more effective than EDDS in reclaiming Cd.


Assuntos
Brassicaceae , Poluentes do Solo , Animais , Suínos , Ácido Nitrilotriacético/toxicidade , Ácido Nitrilotriacético/química , Cádmio/toxicidade , Cádmio/química , Monitoramento Ambiental , Etilenodiaminas/farmacologia , Etilenodiaminas/química , Biodegradação Ambiental , Verduras , Solo/química , Poluentes do Solo/análise , Quelantes/química
3.
Bioorg Med Chem ; 33: 115996, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33494011

RESUMO

In the present work, the radioimmunoconjugates 111In-DTPA-trastuzumab and 177Lu-DOTA-trastuzumab were evaluated regarding the influence of the chelating agents on the physical-chemical parameters and human epidermal growth factor receptor 2 (HER2) tumor cell binding. Data showed that both chelating agents, at predetermined molar ratios (antibody:chelator - 1:10 and 1:20), did not influence the immunoconjugates integrity, the radiolabeling process and the radiolabeled antibodies stability. However, differences were observed in the lipophilic feature between DOTA and DTPA radioimmunoconjugates and in the specific binding to SK-BR-3 tumor cells (HER2 positive). Therefore, this study showed the importance of assessing the influence of chelating agents and their molar ratios in the development process of radioimmunoconjugates.


Assuntos
Anticorpos Monoclonais/farmacologia , Quelantes/farmacologia , Imunoconjugados/farmacologia , Receptor ErbB-2/antagonistas & inibidores , Anticorpos Monoclonais/química , Quelantes/síntese química , Quelantes/química , Relação Dose-Resposta a Droga , Humanos , Imunoconjugados/química , Estrutura Molecular , Receptor ErbB-2/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
4.
Bioconjug Chem ; 32(7): 1204-1213, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32645261

RESUMO

Peptides have been widely adopted as biological targeting vectors for applications in molecular imaging and peptide-receptor radionuclide therapy (PRRT). Somatostatin (SST) analogues such as octreotate (TATE) are exogenous ligands for somatostatin receptors (SSTRs), which are highly expressed on neuroendocrine tumors (NETs). Recently, both [68Ga]Ga-DOTA-TATE (NETSPOT) and [177Lu]Lu-DOTA-TATE (LUTATHERA) received U.S. Food and Drug Administration approval for positron emission tomography (PET) imaging and PRRT of NETs, respectively. However, to the best of our knowledge a well-described synthesis of DOTA-TATE has not been reported in the literature. Herein, we report a fully reoptimized DOTA-TATE synthesis, including the application of a simple ultrasonic bath to greatly improve yields, reduce coupling times, and decrease the amount of reagents required for each coupling step by a half. The most prevalently used cyclizing agents such as iodine, thallium(III) trifluoroacetate, hydrogen peroxide, and dimethyl sulfoxide were compared. On-resin cyclizations using mechanical agitation showed higher yields (23% and 25% using I2 and Tl(III), respectively) than off-resin (1.3% and 11% using DMSO and H2O2, respectively), and the total synthesis time of DOTA-TATE was ∼540 min excluding the cyclization step, with a total synthesis yield of ∼23%. The same manual SPPS methods/reagents were reoptimized with ultrasonic (US) agitation, resulting in an immense reduction in the total synthesis time by ∼8-fold to ∼70 min for DOTA-TATE with a higher yield (∼29% yield), and ∼13-fold to 105 min for DOTA-PEG4-TATE (∼29% yield). Also, the use of US agitation reduces the need for excess molar equivalents of the reagents to a half, which is particularly important when coupling expensive or custom-synthesized groups such as bifunctional chelators and linkers. Finally, the synthesized DOTA-TATE was successfully radiolabeled with [68Ga]Ga3+ (t1/2 = 68 min) with high radiochemical yields (30 min, 95 °C). We believe this work opens the door to the facile and low-cost synthesis of many new chelator-linker-peptide conjugates that were previously cumbersome or cost-prohibitive to produce with manual SPPS.


Assuntos
Compostos Heterocíclicos com 1 Anel/química , Peptídeos/síntese química , Técnicas de Síntese em Fase Sólida/métodos , Ultrassom , Quelantes/química
5.
Toxicol In Vitro ; 66: 104863, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32304792

RESUMO

Inhalation of 60Co3O4 particles may occur at the work place in nuclear industry. Their low solubility may result in chronic lung exposure to γ rays. Our strategy for an improved therapeutic approach is to enhance particle dissolution to facilitate cobalt excretion, as the dissolved fraction is rapidly eliminated, mainly in urine. In vitro dissolution of Co3O4 particles was assessed with two complementary assays in lung fluid surrogates to mimic a pulmonary contamination scenario. Twenty-one molecules and eleven combinations were selected through an extensive search in the literature, based on dissolution studies of other metal oxides (Fe, Mn, Cu) and tested for dissolution enhancement of cobalt particles after 1-28 days of incubation. DTPA, the recommended treatment following cobalt contamination did not enhance 60Co3O4 particles dissolution when used alone. However, by combining molecules with different properties, such as redox potential and chelating ability, we greatly improved the efficacy of each drug used alone, leading for the highest efficacy, to a 2.7 fold increased dissolution as compared to controls. These results suggest that destabilization of the particle surface is an important initiating event for a good efficacy of chelating drugs, and open new perspectives for the identification of new therapeutic strategies.


Assuntos
Radioisótopos de Cobalto/química , Cobalto/química , Descontaminação/métodos , Óxidos/química , Líquidos Corporais , Quelantes/química , Ácido Edético/química , Pulmão , Ácido Pentético/química , Solubilidade
6.
Colloids Surf B Biointerfaces ; 184: 110481, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539751

RESUMO

This study aims to develop a new anti-cancer formulation based on the chelator Dp44mT (Di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone). Dp44mT has outstanding anti-tumor activity and the unique ability to overcome multidrug-resistance in cancer cells. This highly toxic compound has thus far only been applied in free form, limiting its therapeutic effectiveness. To reach its full therapeutic potential, however, Dp44mT should be encapsulated in a nano-carrier that would enable its selective and controlled delivery to malignant cells. As the first step towards this goal, here we encapsulate Dp44mT in nanoparticles (NPs) of poly(lactic-co-glycolic acid) (PLGA), characterize this nano-formulation, and evaluate its therapeutic potential against cancer cells in vitro. Our results showed that the Dp44mT-loaded NPs were homogenous in shape and size, and had good colloidal stability. These PLGA NPs also showed high encapsulation efficiency and loading capacity for Dp44mT and enabled the sustained and tunable release of this chelator. Dp44mT-NPs were uptaken by cancer cells, showed a strong and dose-dependent cytotoxicity towards these cells, and significantly increased apoptotic cell death, in both monolayer and spheroid tumor models. This formulation had a low-level of toxicity towards healthy control cells, indicating an inherent selectivity towards malignant cells. These results demonstrate the great potential of this novel Dp44mT-based nano-formulation for the use in cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Materiais Biocompatíveis/farmacologia , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Tiossemicarbazonas/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacocinética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quelantes/química , Quelantes/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Glioma/tratamento farmacológico , Glioma/patologia , Humanos , Tamanho da Partícula , Tiossemicarbazonas/química , Tiossemicarbazonas/farmacocinética
7.
Environ Sci Pollut Res Int ; 26(23): 23625-23637, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203545

RESUMO

This study reveals the efficient bio-sorption of Cr(VI) species from simulated wastewater using raw (RSV), acid-activated (PSV) and chelated-activated (PSV-C) Sterculia villosa Roxb. shells. Batch optimization experiments were carried out for determining the optimal pH, dosage of bio-sorbent, initial Cr(VI) concentration and incubation temperature. Physico-chemical alterations in the bio-sorbents prior and following bio-sorption of Cr(VI) species were characterized. Equilibrated experimental data at different temperatures was evaluated as a function of time for understanding the isotherm, kinetics and thermodynamics of the bio-sorption process. Sorption rates for all the bio-sorbents (RSV, PSV and PSV-C) alternately fitted to the Langmuir isotherm model and Langmuir maximum adsorption capacity for RSV, PSV and PSV-C were found to be 57.78, 163.51 and 188.68 mg/g, respectively. Cr(VI) sorption by these bio-sorbents followed pseudo-second-order kinetics. Thermodynamic studies suggest endothermic interaction and increased degree of randomness between the bio-sorbents and Cr(VI) species. Regeneration of the bio-sorbents following sorption-desorption revealed that it can be reused and recycled for several times for Cr(VI) removal from wastewater. Graphical abstract.


Assuntos
Quelantes/química , Cromo/química , Poluentes Químicos da Água/química , Adsorção , Biomassa , Cromo/análise , Concentração de Íons de Hidrogênio , Cinética , Sterculia/química , Temperatura , Termodinâmica , Águas Residuárias , Água , Poluentes Químicos da Água/análise , Purificação da Água/métodos
8.
Langmuir ; 35(9): 3354-3362, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30741553

RESUMO

Protein immobilization in a specific conformation or orientation at an interface is influenced by specific interactions with the outer layer of the surface. A strategy to build-up a complex construct which is able to orient protein molecules, based on metal-cation chelation processes, is reported. The proposed methodology implies the formation of a mercaptoundecanoic acid monolayer on a gold surface that is activated to attach covalently the tripeptide glycyl-l-histidyl-l-lysine (GHK) on the surface, whose sites are then employed to chelate copper ions, providing a selective platform for the orientation of human serum albumin (HSA) molecules. The protein adsorption process on GHK and GHK-Cu(II)-complex surfaces was monitored by the in situ quartz crystal microbalance with dissipation monitoring (QCM-D) and force spectroscopy technique. The changes in frequency and dissipation factor as well as the D- f plots from QCM-D measurements help to characterize the changes in the protein conformation and are confirmed by force curve spectroscopy results. An improved kinetic model, based on random sequential adsorption with variable protein footprints, has been developed to predict and simulate the experimentally found HSA average surface coverage onto the GHK and GHK-Cu(II)-complex surfaces.


Assuntos
Quelantes/química , Oligopeptídeos/química , Albumina Sérica Humana/química , Adsorção , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Cobre/química , Humanos , Proteínas Imobilizadas/química , Cinética , Método de Monte Carlo , Conformação Proteica , Técnicas de Microbalança de Cristal de Quartzo , Albumina Sérica Humana/imunologia
9.
Environ Sci Pollut Res Int ; 25(6): 5298-5317, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29294235

RESUMO

Glyphosate-based herbicides (GBHs), consisting of glyphosate and formulants, are the most frequently applied herbicides worldwide. The declared active ingredient glyphosate does not only inhibit the EPSPS but is also a chelating agent that binds macro- and micronutrients, essential for many plant processes and pathogen resistance. GBH treatment may thus impede uptake and availability of macro- and micronutrients in plants. The present study investigated whether this characteristic of glyphosate could contribute to adverse effects of GBH application in the environment and to human health. According to the results, it has not been fully elucidated whether the chelating activity of glyphosate contributes to the toxic effects on plants and potentially on plant-microorganism interactions, e.g., nitrogen fixation of leguminous plants. It is also still open whether the chelating property of glyphosate is involved in the toxic effects on organisms other than plants, described in many papers. By changing the availability of essential as well as toxic metals that are bound to soil particles, the herbicide might also impact soil life, although the occurrence of natural chelators with considerably higher chelating potentials makes an additional impact of glyphosate for most metals less likely. Further research should elucidate the role of glyphosate (and GBH) as a chelator, in particular, as this is a non-specific property potentially affecting many organisms and processes. In the process of reevaluation of glyphosate its chelating activity has hardly been discussed.


Assuntos
Quelantes/química , Ecossistema , Glicina/análogos & derivados , Herbicidas/química , Quelantes/análise , Glicina/química , Herbicidas/toxicidade , Plantas/efeitos dos fármacos , Plantas/metabolismo , Medição de Risco , Solo/química , Microbiologia do Solo , Glifosato
10.
Nucl Med Biol ; 55: 38-46, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29055836

RESUMO

INTRODUCTION: Recent successes in the treatment of metastatic castration-resistant prostate cancer (mCRPCa) by systemic endoradiotherapy has sparked renewed interest in developing small molecule ligands targeting prostate-specific membrane antigen (PSMA) and chelators capable of stable complexation of metal radionuclides for imaging and therapy. As the size and coordination number of metals for imaging, such as 68Ga3+, and for targeted therapy, such as 177Lu3+ and 225Ac3+, are substantially different, they may show a preference for macrocycles of different denticity. We have prepared three simple conjugates that target PSMA and form radiometal complexes through coordination by either octa-, deca-, or dodecadentate tetraazacyclododecane chelators. The complex formation and metal ion selectivity of these constructs were determined at two relevant temperatures, complex stability was examined in vitro, and tumor targeting was demonstrated in preclinical PCa models with a view towards identifying a candidate with potential value as a theranostic agent for the imaging and therapy of mCRPCa. METHODS: Three bifunctional chelates with high denticity, including the octadentate chelate DOTA, the decadentate 3p-C-DEPA and a novel dodecadentate analogue of DEPA, were synthesized and conjugated to a glutamate-urea-lysine (EuK) pharmacophore (EuK-DOTA, EuK-107 and EuK-106, respectively) to enable targeting of PSMA. The metal ion selectivity for each construct was determined by incubation at 25 °C and 95 °C with the trivalent radiometals 68Ga3+, 111In3+, 177Lu3+ and 225Ac3+. PSMA binding affinity was determined by competitive binding using LNCaP cells, while in vivo tumor targeting of the 68Ga-labeled constructs was examined by positron emission tomography (PET) in LNCaP xenograft tumor-bearing mice. RESULTS: PMSA affinities (IC50 values) were 13.3 ± 0.9 nM for EuK-DOTA, 18.0 ± 3.7 nM for EuK-107 and 42.6 ± 6.6 nM for EuK-106. EuK-107 and EuK-DOTA proved to rapidly and near quantitatively complex 68Ga3+, 111In3+, 177Lu3+ and 225Ac3+ at 95 °C, with EuK-107 also rapidly complexing 111In3+ and 177Lu3+ at 25 °C. The inability of EuK-106 to chelate 177Lu3+ and 225Ac3+ suggests that size of the cavity of the macrocylic ring may be more critical than the number of donor groups for the chelation of larger radiometals. In vivo, 68Ga-EuK-107 proved to have similar uptake to 68Ga-DKFZ-PSMA-617, a theranostic ligand currently in clinical evaluation, in a PSMA positive xenograft tumor model. CONCLUSIONS: The broad metal ion selectivity, good in vitro affinity for PSMA and good in vivo tumor targeting suggest that EuK-107, with the 3p-C-DEPA chelator, merits further evaluation as a theranostics construct in prostate cancer.


Assuntos
Antígenos de Superfície/metabolismo , Quelantes/química , Glutamato Carboxipeptidase II/metabolismo , Radioisótopos/química , Actínio/química , Linhagem Celular Tumoral , Estabilidade de Medicamentos , Radioisótopos de Gálio/química , Humanos , Radioisótopos de Índio/química , Cinética , Ligantes , Lutécio/química , Tomografia por Emissão de Pósitrons
11.
ChemMedChem ; 12(18): 1555-1571, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28715615

RESUMO

Zirconium-89 is a positron-emitting radionuclide of high interest for medical imaging applications with positron emission tomography (PET). For the introduction of this radiometal into biologically active targeting vectors, the chelating agent desferrioxamine B (DFO) is commonly applied. However, DFO is known to form 89 Zr complexes of limited in vivo stability. Herein we describe the rational design and chemical development of a new macrocyclic four-hydroxamate-bearing chelating agent-1,10,19,28-tetrahydroxy-1,5,10,14,19,23,28,32-octaazacyclohexatriacontan-2,6,11,15,20,24,29,33-octaone (CTH36)-for the stable complexation of Zr4+ . For this purpose, we first performed computational studies to determine the optimal chelator geometry before we developed different synthesis pathways toward the target structures. The best results were obtained using an efficient solution-phase-based synthesis strategy toward the target chelating agent. To enable efficient and chemoselective conjugation to biomolecules, a tetrazine-modified variant of CTH36 was also developed. The excellent conjugation characteristics of the so-functionalized chelator were demonstrated on the example of the model peptide TCO-c(RGDfK). We determined the optimal 89 Zr radiolabeling parameters for CTH36 as well as its bioconjugate, and found that 89 Zr radiolabeling proceeds efficiently under very mild reaction conditions. Finally, we performed comparative complex stability tests for 89 Zr-CHT36-c(RGDfK) and 89 Zr-DFO-c(RGDfK), showing improved complex stability for the newly developed chelator CTH36.


Assuntos
Quelantes/química , Complexos de Coordenação/química , Desenho de Fármacos , Ácidos Hidroxâmicos/química , Zircônio/química , Complexos de Coordenação/síntese química , Marcação por Isótopo , Espectroscopia de Ressonância Magnética , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/química
12.
J Inorg Biochem ; 166: 68-75, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27838580

RESUMO

Casiopeinas is the generic name of a group of copper chelated complexes designed to be used as antineoplastic. Some of these compounds have shown promising results, and in fact, one of them named Casiopeina III-ia has completed preclinical trials and is ready to start clinical phase I in Mexico. As part of the tests that have to be done to every molecule intended to be used in humans, bacterial assays are required because of their sensitivity, speed and reproducibility and among them, Ames test and the SOS Chromotest are widely used to evaluate DNA damage. With the aim to contribute to complete safety information related to genotoxicity and support the hypothesis about their mode of action, four different Casiopeinas (Cas II-gly, Cas III-Ea, Cas III-ia and Cas III-Ha) were tested for genotoxicity with these assays, as well as differential cytotoxicity upon Escherichia coli mutants defectives in some DNA repair mechanisms. However, although it is well known that these molecules produce DNA breakage, the results of the Chromotest and Ames test were negative. Despite this is controversial, a possible explanation is that there is a direct interaction between DNA and the Casiopeinas tested.


Assuntos
Antineoplásicos , Quelantes , Cobre , Dano ao DNA , Escherichia coli , Compostos Organometálicos , Antineoplásicos/química , Antineoplásicos/farmacologia , Quelantes/química , Quelantes/farmacologia , Ensaios Clínicos Fase I como Assunto , Cobre/química , Cobre/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , México , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia
13.
Methods Mol Biol ; 1510: 405-412, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27761839

RESUMO

Chimeric compounds combine the structural features of inhibitors of histone deacetylases (HDACi) and tyrosine kinase inhibitors (TKi), and therefore unite the effects of a dual-targeting strategy in one compound. Here, we describe the generation of such hybrid molecules. Small molecules, known as TKi, are combined with a Zn2+ chelating motive, preferentially a hydroxamic acid, in addition. The resulting small molecules also can inhibit histone deacetylases, which are dependent on the catalytically active Zn2+. Moreover, we summarize how the growth-inhibitory effects of these combined compounds can be determined with a simple proliferation assay with a leukemic cell line.


Assuntos
Antineoplásicos/síntese química , Quelantes/química , Técnicas de Química Sintética , Inibidores de Histona Desacetilases/química , Ácidos Hidroxâmicos/química , Inibidores de Proteínas Quinases/química , Antineoplásicos/farmacologia , Cátions Bivalentes , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quelantes/farmacologia , Expressão Gênica , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Monócitos/patologia , Inibidores de Proteínas Quinases/farmacologia , Zinco/química , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo
14.
J Environ Sci (China) ; 48: 34-44, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27745670

RESUMO

An efficient and profitable separation process was proposed to prepare 5N (the purity of the metal solution reaches 99.999%) high-purity nickel from 3N nickel-solutions using Purolite S984. The adsorption performance of this superior resin, especially its selectivity for metal ions, was explored quantitatively. The maximum adsorption capacity for copper was 2.286mmol/g calculated by the Langmuir model, which was twice as large as that for nickel. In the binary systems, the adsorption capacity for nickel was decreased by 45%, indicating direct competition for the active sites. The infinite separation factor for copper versus nickel exceeded 300, revealing the feasibility of preparing 5N-level high-purity nickel solutions, which was further verified using the 800BV (bed volume) effluent in the column dynamic process. According to the cost-benefit analysis, purification contributed to a profit of approximately 60,000USD per cycle, and the investment return period was less than 1/3years. Density functional theory analysis confirmed that four nitrogen atoms would be involved in the coordination complex and thus a structure involving two five-membered rings could be achieved. The X-ray photoelectron spectra confirmed the involvement of nitrogen atoms, implying a coordination ratio of approximately 1:1.


Assuntos
Quelantes/química , Fracionamento Químico/métodos , Cobre/química , Modelos Químicos , Níquel/química , Análise Custo-Benefício
15.
Food Funct ; 7(9): 3902-9, 2016 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-27526679

RESUMO

Carrot pomace is an abundant, but underutilized, byproduct from the juice industry. In this study, the insoluble dietary fiber from carrot pomace was treated using an ultra-microgrinding process, and the resulting changes in its physicochemical properties and intestinal protective effect against heavy metal damage were examined. The SEM and fluorescence microscopy results showed that the grinding process could significantly decrease the particle size of carrot insoluble dietary fibre and increase its Brunauer-Emmett-Teller surface area from 0.374 to 1.835 m(2) g(-1). Correspondingly, the water-holding capacity, swelling capacity, and oil-holding capacity increased by 62.09%, 49.25% and 45.45%, respectively. The glucose-, nitrite-, and lead ion-adsorbing abilities also improved significantly compared with the raw samples. In addition, apoptosis assessment by AO/EB revealed that the ground fibre could effectively protect Caco-2 cells from lead ion damage. The MTT assay showed that carrot insoluble dietary fibre has no toxicity for Caco-2 cells at a concentration of 10.0 mg L(-1). The findings of this study highlighted the potential of the ultra-microgrinding process to produce a high added-value fibre ingredient from carrot residues.


Assuntos
Daucus carota/química , Enterócitos/metabolismo , Raízes de Plantas/química , Prebióticos , Substâncias Protetoras/metabolismo , Apoptose/efeitos dos fármacos , Células CACO-2 , Quelantes/efeitos adversos , Quelantes/química , Quelantes/metabolismo , Fenômenos Químicos , China , Daucus carota/economia , Enterócitos/citologia , Enterócitos/efeitos dos fármacos , Manipulação de Alimentos , Indústria de Processamento de Alimentos/economia , Humanos , Resíduos Industriais/análise , Resíduos Industriais/economia , Chumbo/química , Chumbo/metabolismo , Chumbo/toxicidade , Intoxicação por Chumbo/prevenção & controle , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Prebióticos/efeitos adversos , Prebióticos/análise , Prebióticos/economia , Substâncias Protetoras/efeitos adversos , Substâncias Protetoras/química , Substâncias Protetoras/economia , Solubilidade , Propriedades de Superfície
16.
Bull Environ Contam Toxicol ; 96(2): 259-64, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26499324

RESUMO

A long-term field experiment was designed to assess remediation efficiency and ecological risk of phytoremediation of Cd under different cultivation systems with or without ethylene diamine tetraacetic acid (EDTA). EDTA can significantly improve the phytoremediation effectiveness of a historically polluted e-waste dismantling site through enhancing Cd uptake by plants in all cultivation systems along with higher ecological risks to different receptors especially in the presence of Cicer arietinum (chickpea). Moisture content at each layer of soil profile under Eucalyptus globules L. cultivated sites was consistently lower than under chickpea monoculture as a result of E. globules' high water use efficiency. Besides low soil moisture, E. globules can intercept more Cd-rich leachate than chickpea regardless of the presence of EDTA. E. globules could be used for Cd phytoremediation as they can take full advantage of EDTA and decrease ecological risk caused by the chelator.


Assuntos
Cádmio/metabolismo , Quelantes/química , Cicer/metabolismo , Ácido Edético/química , Eucalyptus/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Cádmio/análise , Cádmio/química , China , Ecologia , Medição de Risco , Solo/química , Poluentes do Solo/análise
17.
Anal Chim Acta ; 891: 277-83, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26388387

RESUMO

Alpha-fetoprotein (AFP), a primary marker for many diseases including various cancers, is important in clinical tumor diagnosis and antenatal screening. Most immunoassays provide high sensitivity and accuracy for determining AFP, but they are expensive, often complex, time-consuming procedures. A simple and rapid point-of-care system that integrates Eu (III) chelate microparticles with lateral flow immunoassay (LFIA) has been developed to determine AFP in serum with an assay time of 15 min. The approach is based on a sandwich immunoassay performed on lateral flow test strips. A fluorescence strip reader was used to measure the fluorescence peak heights of the test line (HT) and the control line (HC); the HT/HC ratio was used for quantitation. The Eu (III) chelate microparticles-based LFIA assay exhibited a wide linear range (1.0-1000 IU mL(-1)) for AFP with a low limit of detection (0.1 IU mL(-1)) based on 5ul of serum. Satisfactory specificity and accuracy were demonstrated and the intra- and inter-assay coefficients of variation (CV) for AFP were both <10%. Furthermore, in the analysis of human serum samples, excellent correlation (n = 284, r = 0.9860, p < 0.0001) was obtained between the proposed method and a commercially available CLIA kit. Results indicated that the Eu (III) chelate microparticles-based LFIA system provided a rapid, sensitive and reliable method for determining AFP in serum, indicating that it would be suitable for development in point-of-care testing.


Assuntos
Quelantes/química , Európio/química , Fluorimunoensaio/instrumentação , Fitas Reagentes/análise , alfa-Fetoproteínas/análise , Desenho de Equipamento , Fluorimunoensaio/economia , Humanos , Limite de Detecção , Sistemas Automatizados de Assistência Junto ao Leito
18.
Food Chem Toxicol ; 83: 174-82, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26115597

RESUMO

This study was conducted to prepare and characterize activated carbon (AC) and to evaluate its protective effect against deoxynivalenol (DON) toxicity in rats compared to Egyptian montmorillonite (EM). AC was prepared using a single-step chemical activation with phosphoric acid (H3PO4). The resulted AC has a high surface area and a high total pore volume. Male Sprague-Dawley rats were divided into 6 groups (n = 10) and treated for 3 weeks as follow: the control group, the groups fed AC or EM-supplemented diet (0.5% w/w), the group treated orally with DON (5 mg/kg b.w.) and the groups fed AC or EM-supplemented diet and treated with DON. Blood and liver samples were collected for different analyses. Treatment with DON increased liver function enzymes, lipid peroxidation, tumor necrosis factor α, DNA fragmentation, decreased hepatic glutathione content, up regulating mRNA Fas and TNF-α genes expression and increased micronucleated polychromatic erythrocytes and normochromatic erythrocytes in bone marrow. Co-treatment of DON plus AC or EM succeeded to normalize the levels of the biochemical parameters, reduced the cytotoxicity of bone marrow and ameliorated the hepatic genotoxicity. Moreover, AC was more effective than EM and has a high affinity to adsorb DON and to reduce its cytotoxicity and genotoxicity.


Assuntos
Carbono/uso terapêutico , Carcinógenos Ambientais/toxicidade , Quelantes/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Fígado/efeitos dos fármacos , Mutagênicos/toxicidade , Tricotecenos/antagonistas & inibidores , Animais , Bentonita/uso terapêutico , Carbono/química , Carbono/economia , Carcinógenos Ambientais/química , Quelantes/química , Quelantes/economia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Egito , Indústria de Processamento de Alimentos/economia , Indicadores e Reagentes/química , Resíduos Industriais/análise , Resíduos Industriais/economia , Fígado/metabolismo , Masculino , Mutagênicos/química , Phoeniceae/química , Ácidos Fosfóricos/química , Porosidade/efeitos dos fármacos , Ratos Sprague-Dawley , Sementes/química , Propriedades de Superfície/efeitos dos fármacos , Tricotecenos/toxicidade
19.
Clin Calcium ; 25(5): 711-21, 2015 May.
Artigo em Japonês | MEDLINE | ID: mdl-25926575

RESUMO

Vascular calcification is the abnormality in chronic kidney disease-mineral bone disorder (CKD-MBD) that directly affects the prognosis in relation with cardiovascular diseases. Phosphate binders (PB) are widely used to prevent hyperphosphatemia that can lead to vascular calcification. Two types of PB are available ; calcium (Ca) -based PB and non-Ca-based PB. Non-Ca-based PB has been shown to retard the progression of vascular calcification, while there is a great concern that Ca overload can promote calcification. Moreover, the newer non-Ca-based PBs have been developed including iron and magnesium. We must pay attention to select proper types of PB with costs, pill burdens and specific circumstances observed in Japan.


Assuntos
Doenças Ósseas Metabólicas/etiologia , Quelantes/uso terapêutico , Hiperfosfatemia/etiologia , Hiperfosfatemia/prevenção & controle , Insuficiência Renal Crônica/complicações , Calcificação Vascular/etiologia , Calcificação Vascular/prevenção & controle , Cálcio/efeitos adversos , Doenças Cardiovasculares/etiologia , Quelantes/química , Quelantes/economia , Descoberta de Drogas/tendências , Humanos , Japão , Lantânio , Poliaminas , Prognóstico , Sevelamer
20.
ChemMedChem ; 10(7): 1200-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26011290

RESUMO

For (64) Cu radiolabeling of biomolecules to be used as in vivo positron emission tomography (PET) imaging agents, various chelators are commonly applied. It has not yet been determined which of the most potent chelators--NODA-GA ((1,4,7-triazacyclononane-4,7-diyl)diacetic acid-1-glutaric acid), CB-TE2A (2,2'-(1,4,8,11-tetraazabicyclo[6.6.2]hexadecane-4,11-diyl)diacetic acid), or CB-TE1A-GA (1,4,8,11-tetraazabicyclo[6.6.2]hexadecane-4,11-diyl-8-acetic acid-1-glutaric acid)--forms the most stable complexes resulting in PET images of highest quality. We determined the (64) Cu complex stabilities for these three chelators by a combination of complex challenge and an in vivo approach. For this purpose, bioconjugates of the chelating agents with the gastrin-releasing peptide receptor (GRPR)-affine peptide PESIN and an integrin αv ß3 -affine c(RGDfC) tetramer were synthesized and radiolabeled with (64) Cu in excellent yields and specific activities. The (64) Cu-labeled biomolecules were evaluated for their complex stabilities in vitro by conducting a challenge experiment with the respective other chelators as challengers. The in vivo stabilities of the complexes were also determined, showing the highest stability for the (64) Cu-CB-TE1A-GA complex in both experimental setups. Therefore, CB-TE1A-GA is the most appropriate chelating agent for *Cu-labeled radiotracers and in vivo imaging applications.


Assuntos
Quelantes/química , Compostos Radiofarmacêuticos/química , Animais , Quelantes/síntese química , Quelantes/farmacocinética , Radioisótopos de Cobre , Fígado/química , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Distribuição Tecidual
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