Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.870
Filtrar
1.
Yakugaku Zasshi ; 140(10): 1213-1224, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999200

RESUMO

In basic pharmaceutical sciences to achieve drug development, research on the efficient chemical synthesis of small molecules having cyclic skeletons is important. We have been engaged in the development of artificial catalysts for asymmetric ring formation reactions that exclusively synthesize right-handed or left-handed cyclic compounds and have achieved the construction of optically active cyclic skeletons using our original catalysts. The synthesis of biologically active compounds was facilitated through six-membered ring construction by Diels-Alder reaction of Danishefsky diene; however, no asymmetric variant of the reaction has been achieved. We approached this unresolved issue using multi-coordinated lanthanide metals. A new chiral lanthanide catalyst was developed, and the catalytic asymmetric Diels-Alder reaction of Danishefsky diene was realized for the first time. By modifying the chemical structure of Danishefsky diene, we applied the lanthanide catalyst to the syntheses of polycyclic compounds and biologically active compounds. We achieved the asymmetric synthesis of natural products, antibacterial and antimalarial compounds, and an anti-obesity drug lead compound. Moreover, the novel catalyst exhibited higher performance than the previously reported ones. The latest generation of the catalyst can be handled stably in air at room temperature. Furthermore, we succeeded in the development of new catalysts by focusing on the properties of its metal precursors, such as nickel and indium, and achieved the construction of polycyclic skeletons by using these catalysts.


Assuntos
Compostos Heterocíclicos/síntese química , Compostos Policíclicos/síntese química , Alcenos/química , Antibacterianos/síntese química , Fármacos Antiobesidade/síntese química , Antimaláricos/síntese química , Produtos Biológicos/síntese química , Catálise , Reação de Cicloadição , Desenvolvimento de Medicamentos , Índio , Elementos da Série dos Lantanídeos/química , Níquel , Estereoisomerismo
2.
PLoS One ; 15(7): e0235711, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645091

RESUMO

The current knowledge of the half-lives (T1/2) of several radiolanthanides is either affected by a high uncertainty or is still awaiting confirmation. The scientific information deriving from this imprecise T1/2 data has a significant impact on a variety of research fields, e.g., astrophysics, fundamental nuclear sciences, and nuclear energy and safety. The main reason for these shortcomings in the nuclear databases is the limited availability of suitable sample material together with the difficulties in performing accurate activity measurements with low uncertainties. In reaction to the urgent need to improve the current nuclear databases, the long-term project "ERAWAST" (Exotic Radionuclides from Accelerator Waste for Science and Technology) was launched at Paul Scherrer Institute (PSI). In this context, we present a wet radiochemical separation procedure for the extraction and purification of dysprosium (Dy), terbium (Tb), gadolinium (Gd), and samarium (Sm) fractions from highly radioactive tantalum specimens, in order to obtain 154Dy, 157-158Tb, 148,150Gd, and 146Sm samples, needed for T1/2 determination studies. Ion-exchange chromatography was successfully applied for the separation of individual lanthanides. All separations were conducted in aqueous phase. The separation process was monitored via γ-spectrometry using suitable radioactive tracers. Both the purity and the quantification of the desired radiolanthanides were assessed by inductively coupled plasma mass spectrometry. Test experiments revealed that, prior to the Dy, Tb, Gd, and Sm separation, the removal of hafnium, lutetium, and barium from the irradiated tantalum material was necessary to minimize the overall dose rate exposure (in the mSv/h range), as well to obtain pure lanthanide fractions. With the herein proposed separation method, exotic 154Dy, 157-158Tb, 148,150Gd, and 146Sm radionuclides were obtained in sufficient amounts and purity for the preparation of samples for envisaged half-life measurements. During the separation process, fractions containing holmium, europium, and promethium radionuclides were collected and stored for further use.


Assuntos
Elementos da Série dos Lantanídeos/isolamento & purificação , Radioquímica/métodos , Radioisótopos/química , Cromatografia por Troca Iônica , Európio/isolamento & purificação , Meia-Vida , Hólmio/isolamento & purificação , Elementos da Série dos Lantanídeos/química , Extração Líquido-Líquido/métodos , Espectrometria de Massas , Promécio/isolamento & purificação , Espectrometria gama , Tantálio/química
3.
J Chromatogr A ; 1624: 461219, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540068

RESUMO

The alpha-emitter 225Ac (t1/2 = 9.92 d) is currently under development for targeted alpha-particle therapy of cancer, and accelerator production of 225Ac via proton irradiation of thorium targets requires robust separations of 225Ac from chemically similar fission product lanthanides. Additionally, the lanthanide elements represent critical components in modern technologies, and radiolanthanides such as 140Nd (t1/2 = 3.37 d) also have potential application in the field of nuclear medicine. The ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][NTf2]), combined with the diglycolamide extractant, N,N-dioctyldiglycolamic acid (DODGAA), was adsorbed on macroporous resin support to produce a solvent impregnated resin (SIR) that was investigated for separations of 225Ac and lanthanides. The equilibrium distribution coefficients (Kd) of the rare earth elements (Sc(III), Y(III), Ln(III)), 225Ac(III), Th(IV), and U(VI) on the prepared DODGAA/[Bmim][NTf2]-SIR were determined from batch adsorption experiments in HCl and HNO3 media. The DODGAA/[Bmim][NTf2]-SIR exhibited preferential uptake of the heavier lanthanide elements while allowing for the separation of the lighter lanthanides. Column separations utilizing the DODGAA/[Bmim][NTf2]-SIR were effective at separating the lighter lanthanides from each other, and separating 225Ac from a mixture of lanthanides, 213Bi, and 225Ra without the need for additional complexing agents.


Assuntos
Actínio/isolamento & purificação , Cromatografia por Troca Iônica/métodos , Glicolatos/química , Imidazóis/química , Elementos da Série dos Lantanídeos/química , Líquidos Iônicos/química , Elementos da Série dos Lantanídeos/isolamento & purificação , Porosidade , Solventes/química , Espectrofotometria Atômica
4.
J Vis Exp ; (158)2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32364541

RESUMO

In this work, we describe a protocol for a novel application of hyperspectral imaging (HSI) in the analysis of luminescent lanthanide (Ln3+)-based molecular single crystals. As representative example, we chose a single crystal of the heterodinuclear Ln-based complex [TbEu(bpm)(tfaa)6] (bpm=2,2'-bipyrimidine, tfaa- =1,1,1-trifluoroacetylacetonate) exhibiting bright visible emission under UV excitation. HSI is an emerging technique that combines 2-dimensional spatial imaging of a luminescent structure with spectral information from each pixel of the obtained image. Specifically, HSI on single crystals of the [Tb-Eu] complex provided local spectral information unveiling variation of the luminescence intensity at different points along the studied crystals. These changes were attributed to the optical anisotropy present in the crystal, which results from the different molecular packing of Ln3+ ions in each one of the directions of the crystal structure. The HSI herein described is an example of the suitability of such technique for spectro-spatial investigations of molecular materials. Yet, importantly, this protocol can be easily extended for other types of luminescent materials (such as micron-sized molecular crystals, inorganic microparticles, nanoparticles in biological tissues, or labelled cells, among others), opening many possibilities for deeper investigation of structure-property relationships. Ultimately, such investigations will provide knowledge to be leveraged into the engineering of advanced materials for a wide range of applications from bioimaging to technological applications, such as waveguides or optoelectronic devices.


Assuntos
Elementos da Série dos Lantanídeos/química , Imagem Óptica , Fenômenos Ópticos , Anisotropia , Luminescência
5.
Anal Chem ; 92(10): 7226-7231, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: covidwho-108785

RESUMO

The outbreak of 2019 coronavirus disease (COVID-19) has been a challenge for hospital laboratories because of the huge number of samples that must be tested for the presence of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Simple and rapid immunodiagnostic methods are urgently needed to identify positive cases. Here we report the development of a rapid and sensitive lateral flow immunoassay (LFIA) that uses lanthanide-doped polysterene nanoparticles (LNPs) to detect anti-SARV-CoV-2 IgG in human serum. A recombinant nucleocapsid phosphoprotein of SARS-CoV-2 was dispensed onto a nitrocellulose membrane to capture specific IgG. Mouse anti-human IgG antibody was labeled with self-assembled LNPs that served as a fluorescent reporter. A 100-µL aliquot of serum samples (1:1000 dilution) was used for this assay and the whole detection process took 10 min. The results of the validation experiment met the requirements for clinical diagnostic reagents. A value of 0.0666 was defined as the cutoff value by assaying 51 normal samples. We tested 7 samples that were positive by reverse-transcription (RT-)PCR and 12 that were negative but clinically suspicious for the presence of anti-SARS-CoV-2 IgG. One of the negative samples was determined to be SARS-CoV-2 IgG positive, while the results for the other samples were consistent with those obtained by RT-PCR. Thus, this assay can achieve rapid and sensitive detection of anti-SARS-CoV-2 IgG in human serum and allow positive identification in suspicious cases; it can also be useful for monitoring the progression COVID-19 and evaluating patients' response to treatment.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Elementos da Série dos Lantanídeos/química , Nanopartículas Metálicas/química , Pneumonia Viral/diagnóstico , Betacoronavirus/imunologia , Infecções por Coronavirus/sangue , Humanos , Nanopartículas , Pandemias , Pneumonia Viral/sangue , Sensibilidade e Especificidade
6.
Anal Chem ; 92(10): 7226-7231, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32323974

RESUMO

The outbreak of 2019 coronavirus disease (COVID-19) has been a challenge for hospital laboratories because of the huge number of samples that must be tested for the presence of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Simple and rapid immunodiagnostic methods are urgently needed to identify positive cases. Here we report the development of a rapid and sensitive lateral flow immunoassay (LFIA) that uses lanthanide-doped polysterene nanoparticles (LNPs) to detect anti-SARV-CoV-2 IgG in human serum. A recombinant nucleocapsid phosphoprotein of SARS-CoV-2 was dispensed onto a nitrocellulose membrane to capture specific IgG. Mouse anti-human IgG antibody was labeled with self-assembled LNPs that served as a fluorescent reporter. A 100-µL aliquot of serum samples (1:1000 dilution) was used for this assay and the whole detection process took 10 min. The results of the validation experiment met the requirements for clinical diagnostic reagents. A value of 0.0666 was defined as the cutoff value by assaying 51 normal samples. We tested 7 samples that were positive by reverse-transcription (RT-)PCR and 12 that were negative but clinically suspicious for the presence of anti-SARS-CoV-2 IgG. One of the negative samples was determined to be SARS-CoV-2 IgG positive, while the results for the other samples were consistent with those obtained by RT-PCR. Thus, this assay can achieve rapid and sensitive detection of anti-SARS-CoV-2 IgG in human serum and allow positive identification in suspicious cases; it can also be useful for monitoring the progression COVID-19 and evaluating patients' response to treatment.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Elementos da Série dos Lantanídeos/química , Nanopartículas Metálicas/química , Pneumonia Viral/diagnóstico , Betacoronavirus/imunologia , Infecções por Coronavirus/sangue , Humanos , Nanopartículas , Pandemias , Pneumonia Viral/sangue , Sensibilidade e Especificidade
7.
Chemistry ; 26(27): 6056-6063, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32133687

RESUMO

The properties of LnIII -HPDO3A complexes as relaxation enhancers and paraCEST agents are essentially related to the hydroxylpropyl moiety. A series of three HPDO3A derivatives, with small modifications to the hydroxyl arm, were herein investigated to understand how heightened control can be gained over the parameters involved in the design of these agents. A full 1 H and 17 O-NMR relaxometric analysis was conducted and demonstrated that increasing the length of the OH group from the lanthanide centre significantly enhanced the water exchange rate of the gadolinium complex, but with a subsequent reduction in kinetic stability. Alternatively, the introduction of an additional methyl group, which increased the steric bulk around the OH moiety, resulted in the formation of almost exclusively the TSAP isomer (95 %) as identified by 1 H-NMR of the europium complex. The gadolinium analogue of this complex also exhibited a very fast water exchange rate, but with no detectable loss of kinetic stability. This complex therefore demonstrates a notable improvement over Gd-HPDO3A.


Assuntos
Meios de Contraste/química , Gadolínio/química , Elementos da Série dos Lantanídeos/química , Imagem por Ressonância Magnética/métodos , Európio/química , Compostos Heterocíclicos/química , Cinética , Compostos Organometálicos/química , Água
8.
Dalton Trans ; 49(8): 2397-2402, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32030383

RESUMO

Lanthanides have demonstrated outstanding properties in many fields of research including biology and medicinal chemistry. Their unique luminescence and magnetic properties make them the metals of choice for next generation theranostics that efficiently combine the two central pillars of medicine - diagnostics and therapy. Attached to targeting units, lanthanide complexes pave the way for real-time imaging of drug uptake and distribution as well as specific regulation of subcellular processes with few side effects. This enables individualized treatment options for severe diseases characterized by altered cell expression. The highly diverse results achieved as well as insights into the challenges that research in this area has to face in the upcoming years will be summarized in the present review.


Assuntos
Elementos da Série dos Lantanídeos/química , Luminescência , Substâncias Luminescentes/química , Medicina de Precisão , Nanomedicina Teranóstica , Animais , Humanos
9.
Dalton Trans ; 49(7): 2331-2336, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32022093

RESUMO

The goal of this study was to design a ligand system which can accommodate single lanthanide(iii)-ions and investigate the properties of the resulting complexes. The complexes of all the accesible lanthanides and yttrium with the new ligand LH6 = N,N'-dimethyl-N,N'-ethylene-bis(5-bromo-3-(1H-benzimidazol-2-yl)hydrazineylidene)-2-hydroxybenzylamine) were obtained in high yield at room temperature under aerobic reaction conditions. The corresponding compounds were characterised using X-ray diffraction, FT-IR, elemental analysis and the optical properties of all complexes were investigated using UV-vis and fluorescence spectroscopy. The air stable complexes efficiently transform biomass furfural to trans-4,5-cyclopentenones in high yield.


Assuntos
Complexos de Coordenação/síntese química , Ciclopentanos/metabolismo , Elementos da Série dos Lantanídeos/química , Biomassa , Biotransformação , Catálise , Complexos de Coordenação/química , Cristalografia por Raios X , Ciclopentanos/química , Ligantes , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo
10.
Biomater Sci ; 8(5): 1270-1278, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32067024

RESUMO

In this research, an optimized phosphor combined with naturally green chlorophyll (Phosphor-Chlorophyll, denoted as Ph-chl) was designed for dual-modal luminescence-guided anti-tumor surgery and photodynamic therapy (PDT). A genetic algorithm (GA) is used to solve the "low up-conversion luminescence (UCL) and short-wavelength infrared (SWIR) intensity" problem by coding the proportions of elements in the phosphor in order to find the optimal phosphor with enhanced red UCL emission and SWIR luminescence using Yb/Er in the core and Yb/Nd in the shell. Moreover, when phosphors with different emission light colors (blue and green) are combined with chlorophyll as the control, the results indicate that phosphors with red emission as the energy donor have high PDT efficiency to activate the chlorophyll for reactive oxygen species (ROS) production. Additionally, due to the enhanced penetration and retention (EPR) effect, the as-synthesized Ph-chl could be used for surgery navigation with a higher SWIR imaging effect focusing on cancer rather than normal tissues and paracancerous tissue. Thus, the high dual-modal luminescence guided surgery properties of the final optimized phosphor will promote its further use in minimally-invasive endoscopic clinical surgery navigation.


Assuntos
Clorofila/química , Elementos da Série dos Lantanídeos/química , Nanocompostos/química , Neoplasias Experimentais/cirurgia , Cirurgia Assistida por Computador/métodos , Nanomedicina Teranóstica/métodos , Animais , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Imagem Multimodal/métodos , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/tratamento farmacológico , Fotoquimioterapia/métodos
11.
Chem Soc Rev ; 49(4): 1090-1108, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32016270

RESUMO

Inorganic phosphate has numerous biomedical functions. Regulated primarily by the kidneys, phosphate reaches abnormally high blood levels in patients with advanced renal diseases. Since phosphate cannot be efficiently removed by dialysis, the resulting hyperphosphatemia leads to increased mortality. Phosphate is also an important component of the environmental chemistry of surface water. Although required to secure our food supply, inorganic phosphate is also linked to eutrophication and the spread of algal blooms with an increasing economic and environmental burden. Key to resolving both of these issues is the development of accurate probes and molecular receptors for inorganic phosphate. Yet, quantifying phosphate in complex aqueous media remains challenging, as is the development of supramolecular receptors that have adequate sensitivity and selectivity for use in either blood or surface waters. Metal-based receptors are particularly well-suited for these applications as they can overcome the high hydration enthalpy of phosphate that limits the effectiveness of many organic receptors in water. Three different strategies are most commonly employed with inorganic receptors for anions: metal extrusion assays, responsive molecular receptors, and indicator displacement assays. In this review, the requirements for molecular receptors and probes for environmental applications are outlined. The different strategies deployed to recognize and sense phosphate with metal ions will be detailed, and their advantages and shortfalls will be delineated with key examples from the literature.


Assuntos
Metais/química , Fosfatos/química , Quelantes/química , Complexos de Coordenação/química , Elementos da Série dos Lantanídeos/química , Metais/metabolismo , Fosfatos/metabolismo , Elementos de Transição/química , Água/química
12.
Chem Commun (Camb) ; 56(19): 2897-2900, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32037418

RESUMO

[Tm(DPA)3]3- was used to generate multiple, paramagnetic nuclear Overhauser effect NMR spectra of cationic peptides when weakly bound to a lipopolysaccharide micelle. Increased spectral resolution combined with a marked increase in the number of distance restraints yielded high resolution structures of polymyxin and MSI-594 in the liposaccharide bound state.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Elementos da Série dos Lantanídeos/química , Micelas , Ressonância Magnética Nuclear Biomolecular/métodos , Indicadores e Reagentes/química , Peptídeos/química , Polimixina B/química , Conformação Proteica
13.
Arch Pharm Res ; 43(1): 134-152, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31981073

RESUMO

Together with the development of nanoscience, lanthanide (Ln)-doped upconversion nanoparticles (UCNPs), which can emit UV/VIS light upon irradiation by near-infrared laser sources, is emerging as one of the most favorable materials in the field of nanomedicines. Light-responsive drug delivery is known as an efficient strategy to achieve temporal and spatial controlled drug release. Compared to conventional light-sensitive drug delivery systems, UCNPs are endowed with many advantages, such as deeper tissue penetration and low toxicity. With their unique properties, UCNPs not only serve as potential optical probes for bioimaging but also perform a critical role in therapeutic applications through photon-triggered mechanisms. In particular, UCNPs in combination with different materials and delivery strategies could overcome therapy resistance and enhance therapeutic effectiveness. This article focuses on the current achievements in the last decade of modification methods, diagnostics, and designs of UCNP-based nanoplatforms for successful phototherapy, chemotherapy, and bioimaging.


Assuntos
Sistemas de Liberação de Medicamentos , Elementos da Série dos Lantanídeos/química , Nanopartículas Metálicas/química , Animais , Humanos , Raios Infravermelhos , Nanomedicina
14.
Chemistry ; 26(19): 4350-4377, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31910294

RESUMO

After briefly reviewing the applications of the coordination ability indices proposed earlier for anions and solvents toward transition metals and lanthanides, a new analysis of crystal structures is applied now to a much larger number of coordinating species: anions (including those that are present in ionic solvents), solvents, amino acids, gases, and a sample of neutral ligands. The coordinating ability towards s-block elements is now also considered. The effect of several factors on the coordinating ability will be discussed: (a) the charge of an anion, (b) the chelating nature of anions and solvents, (c) the degree of protonation of oxo-anions, carboxylates and amino carboxylates, and (d) the substitution of hydrogen atoms by methyl groups in NH3 , ethylenediamine, benzene, ethylene, pyridine and aldehydes. Hit parades of solvents and anions most commonly used in the areas of transition metal, s-block and lanthanide chemistry are deduced from the statistics of their presence in crystal structures.


Assuntos
Aminoácidos/química , Ânions/química , Elementos da Série dos Lantanídeos/química , Solventes/química , Elementos de Transição/química , Gases , Hidrogênio , Ligantes
15.
Mater Sci Eng C Mater Biol Appl ; 108: 110381, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31924035

RESUMO

Hyaluronic acid (HA)-functionalized lanthanide-doped KGdF4 nanoparticles were synthesized through two steps on a microfluidic platform. This microfluidic synthesis method allows better control of experimental conditions with lower labor and energy input than traditional beaker synthesis methods for large-scale production of nanoparticles with higher uniformity. First, Ln3+-doped KGdF4 nanoparticles were ultrafast (in minutes) and continuously synthesized using a four-inlets microfluidic chip at room temperature. Then, HA is continuously functionalized on the surface of Ln3+-doped KGdF4 nanoparticles using a T-shape chip through electrostatic adsorption. The synthesized nanoparticles show good uniformity, high biocompatibility, targeted cellular uptake, photoluminescence (PL) and magnetic resonance (MR) properties. This work highlights the potential of microfluidic platform for the development of multifunctional nanoparticles in biomedicine.


Assuntos
Gadolínio/química , Elementos da Série dos Lantanídeos/química , Microfluídica , Nanopartículas/química , Linhagem Celular Tumoral , Sobrevivência Celular , Cor , Difusão Dinâmica da Luz , Humanos , Ácido Hialurônico/química , Luminescência , Nanopartículas/ultraestrutura , Tamanho da Partícula
16.
ACS Appl Mater Interfaces ; 12(4): 4358-4365, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31904925

RESUMO

The lateral flow immunoassay test (LFT), as a method of a point of care test, is widely used in disease diagnosis, food security, and environment observation due to its portability and testing rapidity. A fluorescence lateral flow immunoassay was developed recently to enhance the sensitivity and accuracy of the LFT. However, for most fluorescence reporters, their emission and excitation wavelengths are located in the ultraviolet or visible region. Serum or whole blood significantly absorbs and scatters light of this region, and this will result in background signal interference. In this study, we replace traditional fluorescence reporters with near-infrared lanthanide-doped nanoparticles (NIR-RENPs) to establish a NIR-LFT platform. Blood and other biological samples scatter and absorb less near-infrared light than visible light, and the autofluorescence of biological samples is rarely located in this region. Therefore, using NIR light as a signal can diminish the interference of background noise and suffer from less signal attenuation. In addition, compared with commonly used NIR organic dye, NIR-RENPs have better stability. It is promising that lateral flow immunoassays based on NIR lanthanide-doped nanoparticles are able to acquire a lower detection limit and better accuracy, and they are more suitable for application in commercial settings.


Assuntos
Imunoensaio/métodos , Elementos da Série dos Lantanídeos/química , Análise Química do Sangue , Fluorescência , Humanos , Imunoensaio/instrumentação , Raios Infravermelhos , Limite de Detecção , Nanopartículas/química
17.
Chem Asian J ; 15(1): 182-190, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31769211

RESUMO

Metal-organic frameworks (MOFs) as new classes of proton-conducting materials have been highlighted in recent years. Nevertheless, the exploration of proton-conducting MOFs as formic acid sensors is extremely lacking. Herein, we prepared two highly stable 3D isostructural lanthanide(III) MOFs, {(M(µ3 -HPhIDC)(µ2 -C2 O4 )0.5 (H2 O))⋅2 H2 O}n (M=Tb (ZZU-1); Eu (ZZU-2)) (H3 PhIDC=2-phenyl-1H-imidazole-4,5-dicarboxylic acid), in which the coordinated and uncoordinated water molecules and uncoordinated imidazole N atoms play decisive roles for the high-performance proton conduction and recognition ability for formic acid. Both ZZU-1 and ZZU-2 show temperature- and humidity-dependent proton-conducting characteristics with high conductivities of 8.95×10-4 and 4.63×10-4  S cm-1 at 98 % RH and 100 °C, respectively. Importantly, the impedance values of the two MOF-based sensors decrease upon exposure to formic acid vapor generated from formic aqueous solutions at 25 °C with good reproducibility. By comparing the changes of impedance values, we can indirectly determine the concentration of HCOOH in aqueous solution. The results showed that the lowest detectable concentrations of formic acid aqueous solutions are 1.2×10-2  mol L-1 by ZZU-1 and 2.0×10-2  mol L-1 by ZZU-2. Furthermore, the two sensors can distinguish formic acid vapor from interfering vapors including MeOH, N-hexane, benzene, toluene, EtOH, acetone, acetic acid and butane. Our research provides a new platform of proton-conductive MOFs-based sensors for detecting formic acid.


Assuntos
Formiatos/análise , Elementos da Série dos Lantanídeos/química , Estruturas Metalorgânicas/química , Prótons , Umidade , Tamanho da Partícula , Temperatura
18.
Nanoscale ; 12(3): 1339-1348, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31859321

RESUMO

Lanthanides and actinides are used in a wide variety of applications, from energy production to life sciences. To address toxicity issues due to the chemical, and often radiological, properties of these elements, methods to quantify and recover them from industrial waste are necessary. When used in biomedicine, lanthanides and actinides are incorporated in compounds that show promising therapeutic and/or bioimaging properties, but lack robust strategies to target cancer and other pathologies. Furthermore, current decorporation protocols to respond to accidental actinide exposure rely on intravenous injections of soluble chelating agents, which are inefficient for treatment of inhaled radionuclides trapped in lungs. In recent years, nanoparticles have emerged as powerful tools in both industry and clinical settings. Because some inorganic nanoparticles are sensitive to external stimuli, such as light and magnetic fields, they can be used as building blocks for sensitive bioassays and separation techniques. In addition, nanoparticles can be functionalized with multiple ligands and act as carriers for selective delivery of therapeutic and contrast agents. This review summarizes and discusses recent progress on the use of nanoparticles in lanthanide and actinide chemistry. We examine different types of nanoparticles based on composition, functionalization, and properties, and we critically analyze their performance in a comparative mode. Our focus is two-pronged, including the nanoparticles free of lanthanides and actinides that are used for the detection, separation, or decorporation of f-block elements, as well as the nanoparticles that enhance the inherent properties of lanthanides and actinides for therapeutics, imaging and catalysis.


Assuntos
Elementos da Série Actinoide , Elementos da Série dos Lantanídeos , Nanopartículas Metálicas , Elementos da Série Actinoide/química , Elementos da Série Actinoide/uso terapêutico , Animais , Humanos , Elementos da Série dos Lantanídeos/química , Elementos da Série dos Lantanídeos/uso terapêutico , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico
19.
Biochim Biophys Acta Gen Subj ; 1864(2): 129332, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30928492

RESUMO

We describe the recent progress of structural analysis methods exploiting paramagnetic lanthanide ions. In NMR spectroscopy, the paramagnetic effects induced by the trivalent lanthanide ions provide long-range (~40 Å) distance and angular information that can be exploited in protein structure determination, ligand screening, structure-based resonance assignment, and in-cell observation. The paramagnetic lanthanide ions can also be utilized in EPR spectroscopy, providing nanometer-scale distance measurement. These applications of the paramagnetic lanthanide probe are becoming more widespread by the use of a variety of lanthanide binding tags. Here, we introduce the basics of paramagnetic effects, several examples of lanthanide tags, and recent applications of paramagnetic lanthanide ions in NMR and EPR spectroscopy. Collectively, we show how the paramagnetic lanthanide probe accelerates research in protein science and drug design, and consequently life science.


Assuntos
Espectroscopia de Ressonância de Spin Eletrônica/métodos , Elementos da Série dos Lantanídeos/química , Cisteína/química , Ácido Edético/química , Escherichia coli , Ligantes , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular/métodos , Peptídeos/química , Ligação Proteica , Conformação Proteica , Proteínas/química
20.
Nanotechnology ; 31(7): 072001, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31627201

RESUMO

Near infrared (NIR) excited lanthanide-doped upconversion nanoparticles (UCNPs) are emerging as a new type of fluorescent tag for biological applications, which can emit multi-photon ultraviolet, visible or NIR luminescence for imaging or activation of photosensitive molecules. Here, we present a comprehensive review on recent advances of UCNPs for a manifold of biological applications, including upconversion mechanisms, building bright multicolor upconversion nanocrystals, single nanoparticle and super resolution imaging, in vivo optical and multimodal imaging, photodynamic therapy, light-controlled drug release, biosensing, and toxicities. Our perspectives on the future development of UCNPs are also described.


Assuntos
Elementos da Série dos Lantanídeos/química , Nanopartículas/química , Corantes/química , Humanos , Luminescência , Fotoquimioterapia/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA