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1.
Carbohydr Polym ; 260: 117840, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33712175

RESUMO

Highly efficient shielding materials with an excellent electromagnetic wave absorption have gained increased attention. A new design was used to provide cellulose paper with a high electromagnetic shielding effectiveness (EMI SE) and improve the absorption performance by constructing an asymmetry sandwich structure that consisted of a dense nickel coating, Fe3O4 nanoparticles and a porous nickel layer. This unique structure caused a "multiple reflection-absorb-reflection" process when the electromagnetic waves penetrated the sample. The EMI absorption (SEA) and total SE (SET) increased with Fe3O4 absorption time increasing at 8.2-12.4 GHz, which was attributed to the synergistic effect between porous nickel layer and Fe3O4 nanoparticles. The SEA and SET of the sample with a thickness of 0.195 mm can achieved 18.57 and 41.88 dB, respectively. The design was conducive to improving the magnetic and corrosion resistance properties. This study provided a novel path to obtain a low cost and lightweight electromagnetic shielding material that can reduce secondary radiation.


Assuntos
Celulose/química , Óxido Ferroso-Férrico/química , Níquel/química , Protetores contra Radiação/química , Condutividade Elétrica , Campos Eletromagnéticos , Magnetismo , Nanopartículas Metálicas/química , Porosidade , Propriedades de Superfície , Temperatura
2.
Food Chem ; 345: 128781, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33601653

RESUMO

A new iron-magnetic nanomaterial functionalized with organophosphorus compound was used as solid-phase for arsenic speciation analysis in seafood samples by ICP-MS. The procedure was optimized using chemometric tools and the variables pH = 4.0, 15 min extraction time, and 20 mg of mass of material were obtained as the optimum point. The inorganic arsenic (iAs) extracted using nanoparticles presented concentrations between 20 and 100 µg kg-1 in the evaluated samples. The method was validated for accuracy using CRMs DOLT-5 and DORM-4. It was possible to reuse the same magnetic nanomaterial for 6 successive cycles, and we obtained a detection limit of 16.4 ng kg-1. The proposed method is suitable for the use of inorganic speciation of As, presenting good accuracy, precision, relatively low cost, and acquittance to green chemistry principles.


Assuntos
Arsenicais/análise , Nanopartículas de Magnetita/química , Espectrometria de Massas , Penaeidae/química , Animais , Arsenicais/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Limite de Detecção , Penaeidae/metabolismo , Alimentos Marinhos/análise
3.
Int J Biol Macromol ; 172: 270-280, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33418049

RESUMO

Enzyme immobilization can increase enzyme reusability to reduce cost of industrial production. Ginkgo biloba leaf extract is commonly used for medical purposes, but it contains ginkgolic acid, which has negative effects on human health. Here, we report a novel approach to solve the problem by degrading the ginkgolic acid with immobilized-laccase, where core/shell composite nanoparticles prepared by coaxial electrospraying might be first applied to enzyme immobilization. The core/shell Fe3O4/nylon 6,6 composite nanoparticles (FNCNs) were prepared using one-step coaxial electrospraying and can be simply recovered by magnetic force. The glutaraldehyde-treated FNCNs (FNGCNs) were used to immobilize laccase. As a result, thermal stability of the free laccase was significantly improved in the range of 60-90 °C after immobilization. The laccase-immobilized FNGCNs (L-FNGCNs) were applied to degrade the ginkgolic acids, and the rate constants (k) and times (τ50) were ~0.02 min-1 and lower than 39 min, respectively, showing good catalytic performance. Furthermore, the L-FNGCNs exhibited a relative activity higher than 0.5 after being stored for 21 days or reused for 5 cycles, showing good storage stability and reusability. Therefore, the FNGCNs carrier was a promising enzyme immobilization system and its further development and applications were of interest.


Assuntos
Óxido Ferroso-Férrico/química , Proteínas Fúngicas/química , Ginkgo biloba/química , Lacase/química , Nanopartículas de Magnetita/química , Salicilatos/química , Reagentes para Ligações Cruzadas/química , Técnicas Eletroquímicas , Enzimas Imobilizadas/química , Enzimas Imobilizadas/isolamento & purificação , Reutilização de Equipamento , Proteínas Fúngicas/isolamento & purificação , Glutaral/química , Hidrólise , Cinética , Lacase/isolamento & purificação , Nanopartículas de Magnetita/ultraestrutura , Nylons/química , Extratos Vegetais/química , Folhas de Planta/química , Polyporaceae/química , Polyporaceae/enzimologia
4.
Food Chem ; 347: 129042, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33482488

RESUMO

A new method based on graphene oxide modified (4-phenyl) methanethiol nanomagnetic composite (Fe3O4@4-PhMT-GO) was used for extraction and separation of aluminum from wastewater, food, and vegetable samples in aluminum cookware by microwave dispersive magnetic micro solid-phase extraction (MDM-µ-SPE). In optimized conditions, the working range (WR), the linear range (LR), the limit of detection (LOD), and enrichment factor (EF) were obtained 5-5200 µg L-1, 5-1600 µg L-1, 1.5 µg L-1, and 48.8, respectively (RSD% = 2.5). By MDM-µ-SPE procedure, the aluminum concentrations in baking rice and spinach with aluminum cookware were obtained 97.43 ± 2.57 mg g-1 and 131.64 ± 5.18 mg g-1, respectively which was analyzed by atom trap flame atomic absorption spectrometer (AT-FAAS). The results showed, the aluminum concentrations in cooked foods with Teflon cookware were less than aluminum cookware. The methodology was validated by standard reference materials (SRM) and inductively coupled plasma mass spectrometry analysis (ICP-MS).


Assuntos
Alumínio/análise , Análise de Alimentos/métodos , Microextração em Fase Sólida/métodos , Espectrofotometria Atômica , Verduras/química , Águas Residuárias/química , Adsorção , Alumínio/isolamento & purificação , Óxido Ferroso-Férrico/química , Grafite/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Magnetismo , Micro-Ondas , Sonicação , Compostos de Sulfidrila/química
5.
ACS Appl Mater Interfaces ; 13(4): 5795-5802, 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33480669

RESUMO

A novel ratiometric electrochemical (EC) sensing platform was established for sensitive immunoassay of target cytokeratin 19 fragment 21-1 (CYFRA21-1) biomarker by combining competitive immunoreaction and multisignal output. This immunosensor utilized Ag nanoparticles (NPs)-functionalized urchin-like Fe3O4@polydopamine (u-Fe3O4@PDA-Ag) as a matrix to immobilize CYFRA21-1 antigens and methylene blue (MB)-absorbed Ni3Si2O5(OH)4-Au nanotubes (NTs) to label the anti-CYFRA21-1 (Ab). During the competitive immunoreaction, square wave voltammetric (SWV) current changes of Ag NPs from u-Fe3O4@PDA-Ag indicator and MB from Ni3Si2O5(OH)4-Au/MB indicator are relevant to the dosage of CYFRA21-1-acquired Ni3Si2O5(OH)4-Au/MB/Ab. More importantly, numerous CYFRA21-1 loaded stably on u-Fe3O4@PDA-Ag exhibited strong competitive capacity toward the target-CYFRA21-1 to combine Ni3Si2O5(OH)4-Au/MB/Ab, causing sensitive changes in the ratio of two measured SWV currents. Prominently, "ΔI = ΔIMB + |ΔIAg NPs|" (ΔIMB and |ΔIAg NPs| represents the change values of the oxidation peak currents of MB and Ag NPs, respectively) could be regarded as significantly amplifying the signal response and ultimately improving the sensitivity of CYFRA21-1 detection, from which we derived a wide dynamic range from 500 fg/mL to 50 ng/mL and a low detection limit of 0.39 pg/mL (S/N = 3). This work may exert a profound impact on monitoring other biomarkers in early diagnosis of diseases.


Assuntos
Antígenos de Neoplasias/sangue , Óxido Ferroso-Férrico/química , Ouro/química , Queratina-19/sangue , Azul de Metileno/química , Nanotubos/química , Antígenos de Neoplasias/análise , Técnicas Eletroquímicas/métodos , Humanos , Imunoensaio/métodos , Indóis/química , Queratina-19/análise , Limite de Detecção , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Nanotubos/ultraestrutura , Polímeros/química , Compostos de Silício/química , Prata/química
6.
Carbohydr Polym ; 251: 117109, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142646

RESUMO

Cellulose-modified magnetite-graphene oxide nanocomposite was prepared via click reaction and utilized for immobilization of palladium (Pd) nanoparticles without using additional reducing agent. The abundant OH groups of cellulose provided the uniform dispersion and high stability of Pd nanoparticles, while magnetite-graphene oxide as a supporting material offered high specific surface area and easy magnetic separation. The as-prepared nanocomposite served as a heterogeneous catalyst for the Heck and Sonogashira coupling reactions in various hydrophilic and hydrophobic deep eutectic solvents (DESs) as sustainable and environmentally benign reaction media. Among the fifteen DESs evaluated for coupling reactions, the hydrophilic DES composed of dimethyl ammonium chloride and glycerol exhibited the best results. Due to the low miscibility of catalyst and DES in organic solvents, the separated aqueous phase containing both of the catalyst and DES can be readily recovered by evaporating water and retrieved eight times with negligible loss of catalytic performance.


Assuntos
Celulose/química , Óxido Ferroso-Férrico/química , Grafite/química , Nanocompostos/química , Paládio/química , Catálise , Magnetismo , Extração em Fase Sólida , Solventes/química , Água/química
7.
J Chromatogr A ; 1636: 461735, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33316560

RESUMO

A novel magnetic solid-phase extraction (MSPE) material (Fe3O4@SiO2-NH2-G2) had been prepared and employed for adsorption and analysis of seven quaternary ammonium compounds (QACs) in infant fruit and vegetable products coupled with high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In this paper, Fe3O4@SiO2-NH2-G2 was synthesized based on Fe3O4@SiO2-NH2 and dendrimer (G2) consisting of cyanuric chloride and imidazole. The morphology, configuration and magnetic behavior of the magnetic material were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Critical parameters affecting extraction efficiency, such as the adsorbent amount, sample pH, extraction time, the type of eluent, and desorption time, were optimized. The proposed method provided good linearity with the correlation coefficients (R2) of 0.9992-0.9999, low limits of detection (LODs) (0.05-0.50 µg kg-1) and limits of quantitation (LOQs) (0.20-2.00 µg kg-1). The satisfactory method recoveries in three spiked infant fruit and vegetable products samples were between 80.12% and 101.35% with the relative standard deviations (RSDs) less than 12.04%. In summary, the established method was an effective sample preparation method and showed good prospect for the analysis of QACs in complex matrices.


Assuntos
Dendrímeros/química , Alimentos Infantis/análise , Magnetismo , Nanopartículas/química , Compostos de Amônio Quaternário/análise , Espectrometria de Massas em Tandem/métodos , Adsorção , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Frutas/química , Frutas/metabolismo , Humanos , Imidazóis/química , Lactente , Limite de Detecção , Compostos de Amônio Quaternário/isolamento & purificação , Dióxido de Silício/química , Extração em Fase Sólida , Triazinas/química , Verduras/química , Verduras/metabolismo , Difração de Raios X
8.
J Chromatogr A ; 1636: 461764, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33316565

RESUMO

Stimuli-responsive materials, frequently designated as "smart/intelligent materials", can modify their structure or properties by either a biological, physical, or chemical stimulus which, if properly controlled, could be used for specific applications. Such materials have been studied and exploited in several fields, like electronics, photonics, controlled drugs administration, imaging and medical diagnosis, among others, as well as in Analytical Chemistry where they have been used as chromatographic stationary phases, as part of sensors and for extraction purposes. This review article pretends to provide an overview of the most recent applications of these materials (mostly polymeric materials) in sample preparation for extraction purposes, as well as to provide a general vision of the current state-of-the-art of this field, their potential use and future applications.


Assuntos
Polímeros/química , Óxido Ferroso-Férrico/química , Concentração de Íons de Hidrogênio , Luz , Nanopartículas de Magnetita/química , Micelas , Temperatura
9.
J Chromatogr A ; 1636: 461730, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33326925

RESUMO

Screening and monitoring endogenous peptides from complicated biosamples is still a major challenge in mass spectrometry-based proteomics research, mainly due to their low concentration and the interference of high-abundance proteins and other contaminants in biological samples. Herein, a facile and novel approach was described for rapid fabrication of C18-functionalized magnetic nanocomposites (C18-MNCs) based on one-step aqueous coating of C18-Val-Lys-Val-Lys-Val-Lys (C18-VK-VI) for the highly selective enrichment of low-abundance endogenous peptides from biological samples. C18-VK-VI can readily self-assemble into complete monolayers mainly composed of ß-sheets with C18 hydrophobic chains erecting on the surface of GO@Fe3O4 MNCs under the physiological conditions. The resulting C18VK-VI-GO@Fe3O4 MNCs exhibited good performance for peptides enrichment from digests of standard protein (myoglobin, MYO) and human serum, such as high sensitivity (0.05 fmol µL-1) and selectivity (mass ratio of MYO digests and MYO = 1:500), rapid separation, and good reproducibility. Such a simple mild and rapid one-step aqueous coating method on the basis of oligopeptides self-assembly showed great potential in surface functionalization of various nanoadsorbents for proteome/peptidome researches.


Assuntos
Cromatografia Líquida/métodos , Nanopartículas de Magnetita/química , Oligopeptídeos/química , Peptídeos/química , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Óxido Ferroso-Férrico/química , Grafite/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Mioglobina/química , Mioglobina/metabolismo , Peptídeos/isolamento & purificação , Reprodutibilidade dos Testes
10.
J Chromatogr A ; 1636: 461776, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33340749

RESUMO

To address the undesirably low porosity of phenolic resin, a new material termed magnetic mesoporous metal-phenolic coordination spheres (Fe3O4@Co-TA) was synthesized by chelating tannic acid (TA) with metal ions. Fe3O4@Co-TA was characterized by transmission electron microscopy, scanning electron microscopy, hysteresis loop (B-H) analysis, Fourier-transform infrared spectroscopy, and N2 adsorption-desorption. The results indicated that the new material comprises mesopores (2 nm and 3 nm) and exhibits a good magnetic response (44 emu/g). Combined with high-performance liquid chromatography (HPLC), a novel method for the detection of crystal violet (CV) and leucocrystal violet (LCV) by magnetic solid-phase extraction was established. Under the optimal extraction conditions, the linear ranges of CV and LCV detection were 0.2‒60 µg/L and 0.04‒40 µg/L, the detection limits were 0.04 µg/L and 0.008 µg/L, and the enrichment factors were 435 and 460, respectively. Fe3O4@Co-TA was reused ten times without significant reduction of the extraction ability. This method was successfully used for the detection of CV and LCV in fish samples, providing an effective technique for food safety monitoring and quality control.


Assuntos
Complexos de Coordenação/química , Peixes/metabolismo , Violeta Genciana/química , Extração em Fase Sólida/métodos , Adsorção , Animais , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Violeta Genciana/isolamento & purificação , Limite de Detecção , Magnetismo , Porosidade , Reciclagem , Taninos/química
11.
Int J Biol Macromol ; 171: 198-207, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33310102

RESUMO

Chitosan is a linear polysaccharide and non-toxic bioactive polymer with a wide variety of applications due to its functional properties such as ease of modification, and biodegradability. In this investigation, magnetic cores (Fe3O4) were synthesized using a fabrication method involving coprecipitation of Fe2+ and Fe3+. Then the magnetic nanoparticles were encapsulated by chitosan layers. In the next step, magnetite-gold composite nanoparticles were synthesized with spherical shapes and sizes ranging from 20 to 30 nm, using sodium citrate as a natural reducing agent. The morphological and physicochemical features of the material were determined using several advanced techniques like FT-IR, ICP analysis, FESEM, EDS, XRD, TEM, XPS and VSM. In the biological part of the present study, the cell viability of Fe3O4, HAuCl4, and Fe3O4@CS/AuNPs was very low against human colorectal carcinoma cell lines i.e. Ramos.2G6.4C10, HCT-8 [HRT-18], HCT 116, and HT-29, human gastric cancer cell lines i.e. MKN45, AGS, and KATO III, and human pancreatic cancer cell lines i.e. PANC-1, AsPC-1, and MIA PaCa-2. The IC50 of Fe3O4@CS/AuNPs against Ramos.2G6.4C10, HCT-8 [HRT-18], HCT 116, HT-29, MKN45, AGS, KATO III, PANC-1, AsPC-1, and MIA PaCa-2 cell lines were 385, 429, 264, 286, 442, 498, 561, 513, 528, and 425 µg/mL, respectively. Thereby, the best cytotoxicity results of our Fe3O4@CS/AuNPs were observed in the case of the HCT 116 cell line. Seemingly, the present nanoparticles may be used for the treatment of several types of gastro-duodenal cancers especially colon, gastric, and pancreatic cancers in near future.


Assuntos
Antineoplásicos/química , Quitosana/química , Cloretos/química , Óxido Ferroso-Férrico/química , Compostos de Ouro/química , Nanopartículas de Magnetita/química , Nanocompostos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Composição de Medicamentos/métodos , Células HCT116 , Células HT29 , Humanos , Nanopartículas de Magnetita/ultraestrutura , Nanocompostos/ultraestrutura , Propilaminas/química , Silanos/química
12.
Food Chem ; 345: 128841, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33360062

RESUMO

In this study, a novel porous composite (Fe3O4@TAPB-COF@ZIF-8) consisting of metal-organic and covalent organic frameworks was developed and applied to the magnetic solid-phase extraction (MSPE) of bisphenols. The extraction parameters such as the extraction time, solution pH, amounts of adsorbent, and ionic strength were investigated to obtain the best extraction conditions. By optimizing the MSPE, a convenient and sensitive analytical method was established in combination with high-performance liquid chromatography. The method achieved low detection limits (0.04-0.05 ng mL-1), wide linear range (0.25-1000 ng mL-1), good repeatability (1.20-4.30%), good reproducibility (1.34-4.03%), and satisfactory recoveries of four functional beverages (66.2-116.6%).


Assuntos
Compostos Benzidrílicos/análise , Compostos Benzidrílicos/isolamento & purificação , Bebidas/análise , Limite de Detecção , Fenômenos Magnéticos , Estruturas Metalorgânicas/química , Fenóis/análise , Fenóis/isolamento & purificação , Extração em Fase Sólida/métodos , Adsorção , Compostos Benzidrílicos/química , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Concentração Osmolar , Fenóis/química , Porosidade , Reprodutibilidade dos Testes
13.
Food Chem ; 339: 127855, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32858384

RESUMO

A magnetic o-hydroxyazobenzene (M-HAzo) porous organic polymer was facilely prepared by a green azo coupling reaction in aqueous solution. The prepared M-HAzo was applied as a new adsorbent for the first time to pre-concentrate phthalate esters (PAEs) from plastic bottled juice, followed by their determination with high performance liquid chromatography-ultraviolet detection. The effects of various parameters, i.e., the mass ratio of the Fe3O4@SiO2 to HAzo, extraction time, ionic strength, pH of the sample, desorption conditions were optimized. Under the optimized conditions, the M-HAzo based method exhibited good performance in terms of linear range (0.3-50.0 µg L-1), detection limit (0.08-0.50 µg L-1), accuracy (recovery of 78.0-115.0%) and repeatability (relative standard deviation of 2.9-7.8%). This work provides a sensitive method for analysis of PAEs at trace levels in drinks, which is featured with high sensitivity, simple operation and environmentally-friendly merit and will have a promising potential in analysis of other organic pollutants.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ésteres/análise , Magnetismo , Ácidos Ftálicos/química , Compostos Azo/química , Ésteres/isolamento & purificação , Óxido Ferroso-Férrico/química , Sucos de Frutas e Vegetais/análise , Limite de Detecção , Polímeros/química , Reprodutibilidade dos Testes , Dióxido de Silício/química , Extração em Fase Sólida , Espectrofotometria Ultravioleta
14.
J Chromatogr A ; 1637: 461809, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33360639

RESUMO

In this study, for the first time, magnetic solid phase extraction (MSPE) was combined with in-situ derivatization to determine alendronate in plasma. TiO2 coated Fe3O4 microspheres (denoted as Fe3O4@TiO2) were synthesized via polydopamine coating, titanium ions immobilizing and calcination steps. The as-prepared microspheres could selectively extract alendronate and be quickly isolated from plasma. The drug-adsorbed Fe3O4@TiO2 microspheres were then directly incubated in derivatization reagent solution to perform novel in-situ derivatization and elution procedure, in which the derivatized alendronate lost its affinity to TiO2 and was spontaneously eluted for further LC-MS/MS detection. Satisfactory results were obtained on the creative attempt to couple dispersive magnetic solid phase extraction with in-situ derivatization. The developed method was validated and demonstrated good linearity (0.05-500 ng mL-1), low detection limit (20 pg mL-1), great accuracy (100.6% to 105.3%) and precision (RSDs<5.27%). Manual operation and analysis time could be greatly reduced compared to other reported methods. The method was successfully applied to a pharmacokinetic study in beagle dogs.


Assuntos
Alendronato/sangue , Conservadores da Densidade Óssea/sangue , Óxido Ferroso-Férrico/química , Magnetismo , Microesferas , Extração em Fase Sólida/métodos , Titânio/química , Animais , Cromatografia Líquida , Cães , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem
15.
Chemosphere ; 262: 127901, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32805660

RESUMO

In this work, Lysinibacillus sp. JLT12 was used to remove the Cr(VI)-induced passive layer on the magnetite. Mechanism study via dynamic kinetics, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy analyses revealed that Lysinibacillus sp. JLT12 could remove the passive layer (lepidocrocite and goethite) to facilitate the further Cr(VI) reduction by magnetite. For large-scale applications, porous ceramsite (PC) was prepared with magnetite, kaolin, and fallen leaves. Lysinibacillus sp. was then immobilized on the holes in PC. Slow-released nutrients were added to immobilized porous ceramsite (IM-PC) at a ratio of 1.5:10 (g/g) to supply carbon, nitrogen, and phosphorus to Lysinibacillus sp. JLT12 with low secondary pollution. The performance of IM-PC was evaluated via a column experiment. The results indicate that, in the presence of Lysinibacillus, the break-through time and maximum adsorption ability of IM-PC were 11.67 h and 121.47 mg/g, respectively. These values are higher than those of PC. Additionally, break-through curves detected at 5, 10, and 15 days demonstrated that the usage life of IM-PC was significantly longer than that of PC.


Assuntos
Cromo/química , Óxido Ferroso-Férrico/química , Poluentes Químicos da Água/química , Adsorção , Bacillus , Biodegradação Ambiental , Carbono , Cromo/análise , Compostos Férricos , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia Fotoeletrônica , Poluentes Químicos da Água/análise , Difração de Raios X
16.
Molecules ; 26(1)2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-33379377

RESUMO

This study developed a nano-magnetite-modified biochar material (m-biochar) using a simple and rapid in situ synthesis method via microwave treatment, and systematically investigated the removal capability and mechanism of chromium (VI) by this m-biochar from contaminated groundwater. The m-biochar was fabricated from reed residues and magnetically modified by nano-Fe3O4. The results from scanning electron microscopy (SEM) and X-ray diffraction (XRD) characterisations confirmed the successful doping of nano-Fe3O4 on the biochar with an improved porous structure. The synthesised m-biochar exhibited significantly higher maximum adsorption capacity of 9.92 mg/g compared with that (8.03 mg/g) of the pristine biochar. The adsorption kinetics followed the pseudo-second-order model and the intraparticle diffusion model, which indicated that the overall adsorption rate of Cr(VI) was governed by the processes of chemical adsorption, liquid film diffusion and intramolecular diffusion. The increasing of the pH from 3 to 11 significantly affected the Cr(VI) adsorption, where the capabilities decreased from 9.92 mg/g to 0.435 mg/g and 8.03 mg/g to 0.095 mg/g for the m-biochar and pristine biochar, respectively. Moreover, the adsorption mechanisms of Cr(VI) by m-biochar were evaluated and confirmed to include the pathways of electrostatic adsorption, reduction and complexation. This study highlighted an effective synthesis method to prepare a superior Cr(VI) adsorbent, which could contribute to the effective remediation of heavy metal contaminations in the groundwater.


Assuntos
Carvão Vegetal/química , Cromo/química , Óxido Ferroso-Férrico/química , Água Subterrânea/química , Poluentes Químicos da Água/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Magnetismo/métodos , Micro-Ondas , Nanopartículas
17.
Int J Nanomedicine ; 15: 10331-10347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33376324

RESUMO

Background: Lung cancer is the leading cause of cancer patient death in the world. There are many treatment options for lung cancer, including surgery, radiation therapy, chemotherapy, targeted therapy, and combined therapy. Despite significant progress has been made in the diagnosis and treatment of lung cancer during the past few decades, the prognosis is still unsatisfactory. Purpose: To resolve the problem of chemotherapy failure, we developed a magnetite-based nanomedicine for chemotherapy acting synergistically with loco-regional hyperthermia. Methods: The targeting carrier consisted of a complex of superparamagnetic iron oxide (SPIO) and poly(sodium styrene sulfonate) (PSS) at the core and a layer-by-layer shell with cisplatin (CDDP), together with methotrexate - human serum albumin conjugate (MTX-HSA conjugate) for lung cancer-specific targeting, referred to hereafter as SPIO@PSS/CDDP/HSA-MTX nanoparticles (NPs). Results: SPIO@PSS/CDDP/HSA-MTX NPs had good biocompatibility and stability in physiological solutions. Furthermore, SPIO@PSS/CDDP/HSA-MTX NPs exhibited a higher temperature increase rate than SPIO nanoparticles under irradiation by a radiofrequency (RF) generator. Therefore, SPIO@PSS/CDDP/HSA-MTX NPs could be used as a hyperthermia inducer under RF exposure after nanoparticles preferentially targeted and then accumulated at tumor sites. In addition, SPIO@PSS/CDDP/HSA-MTX NPs were developed to be used during combined chemotherapy and hyperthermia therapy, exhibiting a synergistic anticancer effect better than the effect of monotherapy. Conclusion: Both in vitro and in vivo results suggest that the designed SPIO@PSS/CDDP/HSA-MTX NPs are a powerful candidate nanoplatform for future antitumor treatment strategies.


Assuntos
Óxido Ferroso-Férrico/química , Hipertermia Induzida , Neoplasias Pulmonares/terapia , Nanomedicina/métodos , Animais , Linhagem Celular Tumoral , Cisplatino/química , Cisplatino/uso terapêutico , Terapia Combinada , Portadores de Fármacos/química , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Metotrexato/química , Nanopartículas/química , Albumina Sérica/química
18.
Chemosphere ; 261: 128118, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113641

RESUMO

Lanthanum based nanocomposites have attracted much attention for their efficiency and capacity in removing phosphate from water. This study developed a Fe3O4/La(OH)3 nanocomposite through a precipitation route at room temperature and used the nanocomposite to remove phosphate from river water. Performance of the Fe3O4/La(OH)3 nanocomposite was evaluated in terms of sorption kinetics, sorption isotherms, different solution pH values, competing ions, and regenerative ability. The Fe3O4/La(OH)3 nanocomposite showed a nanosphere-like morphology with 97% magnetic separation efficiency, excellent phosphate removal capacity of 253.83 mg/g, 99% phosphate selectivity in the presence of chloride, nitrate, sulfate, fluoride, and calcium as competing ions and excellent reusability in ten cycles. Based on these findings, the Fe3O4/La(OH)3 nanocomposite was used to remove phosphate from river water. It was found that, in 60 min, a 0.1 g/L dosage of the nanocomposite was able to reduce the phosphate in the water from 0.087 mg/L to 0.002 mg/L. Moreover, studying of the removal mechanism of the nanocomposite revealed that surface complexation and the electrostatic interaction between phosphate species and lanthanum hydroxide played a prominent role in the sorption of phosphate.


Assuntos
Óxido Ferroso-Férrico/química , Lantânio/química , Nanocompostos/química , Fosfatos/análise , Rios/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Cinética , Propriedades de Superfície
19.
Chemosphere ; 254: 126898, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957293

RESUMO

The utilization of Microcystis biomass is an urgent issue in the mitigation of cyanobacterial bloom. In this study, Microcystis-derived biochar (MB) and Fe3O4-modified biochar (Fe3O4/MB) were fabricated for the U(VI) elimination. The results showed that U(VI) sorption process by either MB or Fe3O4/MB was pH-dependent and ionic strength-independent. The maximum sorption capacity of MB was higher than that of Fe3O4/MB. According to the analysis of X-ray photoelectron spectroscopy, U(VI) sorption on both MB and Fe3O4/MB was mainly ascribed to the surface complexation between U(VI) and oxygen-containing functional groups on the surface of MB. Fe3O4 particles on the surface of MB didn't provide extra active sites for the sorption of U(VI), but it enabled the adsorbent to be magnetically separated. Five consecutive sorption/desorption cycles verified the good reusability of Fe3O4/MB in this study. Therefore, the investigation is not only meaningful for the utilization of nuisance biomass from cyanobacterial blooms, but also provides novel adsorbents for the U(VI) removal from aqueous solutions.


Assuntos
Carvão Vegetal/química , Eutrofização , Óxido Ferroso-Férrico/química , Microcystis/química , Urânio/análise , Poluentes Radioativos da Água/análise , Purificação da Água/métodos , Adsorção , Biomassa , Concentração de Íons de Hidrogênio , Fenômenos Magnéticos , Modelos Teóricos , Concentração Osmolar
20.
J Vasc Interv Radiol ; 31(10): 1697-1705.e3, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32773247

RESUMO

PURPOSE: To develop bile acid-stabilized multimodal magnetic resonance (MR) imaging and computed tomography (CT)-visible doxorubicin eluting lipiodol emulsion for transarterial chemoembolization of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Ferumoxytol, a US Food and Drug Administration-approved iron oxide nanoparticle visible under MR imaging was electrostatically complexed with doxorubicin (DOX). An amphiphilic bile acid, sodium cholate (SC), was used to form a stable dispersion of ferumoxytol-DOX complex in lipiodol emulsion. Properties of the fabricated emulsion were characterized in various component ratios. Release kinetics of DOX were evaluated for the chemoembolization applications. Finally, in vivo multimodal MR imaging/CT imaging properties and potential therapeutic effects upon intra-arterial (IA) infusion bile acid-stabilized ferumoxytol-DOX-lipiodol emulsion were evaluated in orthotopic McA-Rh7777 HCC rat models. RESULTS: DOX complexed with ferumoxytol through electrostatic interaction. Amphiphilic SC bile acid at the interface between the aqueous ferumoxytol-DOX complexes and lipiodol enabled a sustained DOX release (17.2 ± 1.6% at 24 hours) at an optimized component ratio. In McA Rh7777 rat HCC model, IA-infused emulsion showed a significant contrast around tumor in both T2-weighted MR imaging and CT images (P = .044). Hematoxylin and eosin and Prussian blue staining confirmed the local deposition of IA-infused SC bile acid-stabilized emulsion in the tumor. The deposited emulsion induced significant increases in TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) stain-positive cancer cell apoptosis compared to those in a group treated with the nonstabilized emulsion. CONCLUSIONS: SC bile acid-stabilized ferumoxytol-DOX-lipiodol emulsion demonstrated sustained drug release and multimodal MR imaging/CT imaging capabilities. The new lipiodol-based formulation may enhance the therapeutic efficacy of chemoembolization in HCC.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica , Meios de Contraste/administração & dosagem , Doxorrubicina/administração & dosagem , Óleo Etiodado/administração & dosagem , Óxido Ferroso-Férrico/administração & dosagem , Neoplasias Hepáticas Experimentais/terapia , Colato de Sódio/administração & dosagem , Animais , Antibióticos Antineoplásicos/química , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Meios de Contraste/química , Doxorrubicina/química , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Emulsões , Óxido Ferroso-Férrico/química , Infusões Intra-Arteriais , Cinética , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Neoplasias Hepáticas Experimentais/patologia , Imagem por Ressonância Magnética , Imagem Multimodal , Ratos Sprague-Dawley , Colato de Sódio/química , Tomografia Computadorizada por Raios X
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