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1.
Chemistry ; 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34634149

RESUMO

Organic materials with multiple emissions tunable by external stimuli represent a great challenge. TTPyr, crystallizing in different polymorphs, shows a very rich photophyisics comprising excitation-dependent fluorescence and phosphorescence at ambient conditions, and mechanochromic and thermochromic behavior. Transformation among the different species has been followed by thermal and X-ray diffraction analyses and the emissive features interpreted through structural results and DFT/TDDFT calculations. Particularly intriguing is the polymorph TTPyr(HT), serendipitously obtained at high temperature but stable also at room temperature, whose non-centrosymmetric structure guarantees an SHG efficiency 10 times higher than that of standard urea. Its crystal packing, where only the TT units are strongly rigidified by π-π stacking interactions while the Pyr moieties possess partial conformational freedom, is responsible for the observed dual fluorescence. The potentialities of TTPyr for bioimaging have been successfully established.

2.
Theranostics ; 9(11): 3223-3248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31244951

RESUMO

Pathogenic bacteria, fungi and viruses pose serious threats to the human health under appropriate conditions. There are many rapid and sensitive approaches have been developed for identification and quantification of specific pathogens, but many challenges still exist. Culture/colony counting and polymerase chain reaction are the classical methods used for pathogen detection, but their operations are time-consuming and laborious. On the other hand, the emergence and rapid spread of multidrug-resistant pathogens is another global threat. It is thus of utmost urgency to develop new therapeutic agents or strategies. Luminogens with aggregation-induced emission (AIEgens) and their derived supramolecular systems with unique optical properties have been developed as fluorescent probes for turn-on sensing of pathogens with high sensitivity and specificity. In addition, AIE-based supramolecular nanostructures exhibit excellent photodynamic inactivation (PDI) activity in aggregate, offering great potential for not only light-up diagnosis of pathogen, but also image-guided PDI therapy for pathogenic infection.


Assuntos
Anti-Infecciosos/administração & dosagem , Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/tratamento farmacológico , Testes Diagnósticos de Rotina/métodos , Corantes Fluorescentes/química , Substâncias Macromoleculares/metabolismo , Nanomedicina Teranóstica/métodos , Animais , Anti-Infecciosos/farmacologia , Humanos , Nanopartículas Multifuncionais/administração & dosagem , Nanopartículas Multifuncionais/metabolismo , Imagem Óptica/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/farmacologia , Sensibilidade e Especificidade
3.
Chem Asian J ; 14(6): 770-774, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30536637

RESUMO

In this work, we aim to develop cancer cell-targeting AIE dots based on a polyyne-bridged red-emissive AIEgen, 2TPE-4E, through the combination of metabolic engineering and bio-orthogonal reactions. Azide groups on a tumor were efficiently produced by intravenous injection of Ac4ManNAz and glycol-metabolic engineering. These bio-orthogonal azide groups could facilitate the specific targeting of DBCO-AIE dots to the tumor cells undergoing metal-free click reaction in vivo. The efficiency of this targeting strategy could be further improved with the development of new bio-orthogonal chemical groups with higher reactivity and a large amount of AIEgens could be delivered to the tumor for diagnosis.


Assuntos
Engenharia Metabólica , Poli-Inos/química , Animais , Azidas/química , Química Click , Feminino , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Hexosaminas/química , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Neoplasias/diagnóstico , Neoplasias/diagnóstico por imagem , Neoplasias/metabolismo , Pontos Quânticos/química , Espectrometria de Fluorescência , Estilbenos/química , Transplante Heterólogo
4.
Theranostics ; 8(18): 4925-4956, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30429878

RESUMO

The utilization of luminogens with aggregation-induced emission (AIE) characteristics has recently been developed at a tremendous pace in the area of theranostics, mainly because AIE luminogens (AIEgens) hold various distinct advantages, such as good biocompatibility, excellent fluorescence properties, simple preparation and modification, perfect size of nano-aggregation for enhanced permeability and retention effect, promoted efficiencies of photodynamic and photothermal therapies, efficient photoacoustic imaging, and ready constructions of multimodal imaging and therapy. Significant breakthroughs and developments of theranostics based on AIEgens have been achieved in the past few years, and great progress has been witnessed in many theranostic modalities, indicating that AIEgens remarkably complement conventional theranostic materials and promote the development of theranostics. This review provides theoretical insights into the advantages of AIEgens in theranostics, and systematically summarizes the basic concepts, seminal studies, recent trends and perspectives in theranostics based on AIEgens. We believe that AIEgens would be promising multifunctional theranostic platforms in clinical fields and facilitate significant advancements in this research-active area.


Assuntos
Imagem Molecular/métodos , Terapia de Alvo Molecular/métodos , Nanomedicina/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Nanomedicina Teranóstica/métodos , Animais , Modelos Animais de Doenças , Nanomedicina/tendências , Nanomedicina Teranóstica/tendências
5.
Anal Chem ; 90(2): 1063-1067, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29275625

RESUMO

A facile and simple one-step method was developed to fabricate aptamer-decorated self-assembled organic dots with aggregation-induced emission (AIE) characteristics. With integration of the advantages of AIE aggregates with strong emission and the cell-targeting capability of aptamers, the as-prepared Apt-AIE organic nanodots can specifically target to cancer cells with good biocompatibility, high image constrast, and photostability. On the basis of this universal method, a variety of versatile organic fluorescent nanoprobes with high brightness, specific recognition, and clinical-transitional potential could be facilely constructed for biological sensing and imaging applications.


Assuntos
Aptâmeros de Nucleotídeos/química , Corantes Fluorescentes/química , Nanopartículas/química , Neoplasias/diagnóstico por imagem , Imagem Óptica/métodos , Células A549 , Dimerização , Fluorescência , Humanos , Células MCF-7
6.
Adv Healthc Mater ; 5(4): 427-31, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26688031

RESUMO

In this work, a morpholine-functionalized aggregation-induced emission luminogen (AIEgen), AIE-LysoY, is reported for lysosomal imaging and autophagy visualization. To attain outstanding imaging contrast, AIE-LysoY is equipped with excited state intramolecular proton transfer (ESIPT) characteristic. AIE-LysoY provides a new platform for lysosome visualization with good biocompatibility, large Stokes shift, superior signal-to-noise ratio, and high photostability.


Assuntos
Autofagia , Lisossomos/metabolismo , Sondas Moleculares/química , Morfolinas/química , Materiais Biocompatíveis/química , Sobrevivência Celular , Células HeLa , Humanos , Microscopia de Fluorescência , Prótons , Razão Sinal-Ruído
8.
Sci Rep ; 4: 4272, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24603274

RESUMO

In this work, we design and synthesize a malonitrile-functionalized TPE derivative (TPE-DCV), which can react with thiol group through thiol-ene click reaction, leading to the fluorescence change of the system. Combined with the unique AIE property, TPE-DCV can selectively detect glutathione (GSH) but not cysteine or homocysteine. As the cleavage of GSSG with the aid of glutathione reductase produces GSH, which turns on the fluorescence of TPE-DCV, the ensemble of TPE-DCV and GSSG can thus serve as a label-free sensor for enzymatic activity assay of glutathione reductase. We also apply TPE-DCV for the detection of intracellular GSH in living cells.


Assuntos
Ensaios Enzimáticos/métodos , Corantes Fluorescentes , Glutationa/metabolismo , Ativação Enzimática , Corantes Fluorescentes/química , Glutationa/química , Glutationa Redutase/metabolismo , Células HeLa , Humanos , Cinética
9.
Chem Asian J ; 8(8): 1806-12, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23596133

RESUMO

The detection of nucleic acids, such as DNA and RNA, plays a significant role in genetic engineering, forensics, and bioinformatics. Traditional nucleic acid probes are mainly intercalators, which are potential mutagens, or groove binders that show high preference only for double-stranded DNA. We herein present two versatile fluorescent probes for nucleic acid detection and visualization. The nonemissive tetraphenylethene derivatives (TTAPE) are induced by DNA/RNA to emit, thereby showing a novel phenomenon of aggregation-induced emission (AIE). This kind of "light-up" property enables the quantitation and visualization of nucleic acids in aqueous solution and electrophoretic gels, respectively. The cationic TTAPE can penetrate cells with a compromised plasma membrane easily but cannot enter live cells with an intact membrane, thus making them useful for the differentiation between dead and live cells. On account of the high binding affinity to DNA, TTAPE can selectively label the chromosomes and nuclei in fixed cells, which provides a simple and fast method for the observation of cell mitosis. Owing to their AIE characteristics, the dye molecules aggregate in DNA-rich regions and exert appreciable quantum efficiency as well as superior photostability.


Assuntos
DNA/análise , Corantes Fluorescentes/química , Compostos de Amônio Quaternário/química , Estilbenos/química , Animais , Linhagem Celular Tumoral , Cromossomos/química , Drosophila/genética , Células HeLa , Humanos , Microscopia de Fluorescência , Espectrometria de Fluorescência , Eletricidade Estática , Água/química
10.
J Am Chem Soc ; 135(1): 62-5, 2013 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-23244346

RESUMO

Tracking the dynamics of mitochondrial morphology has attracted much research interest because of its involvement in early stage apoptosis and degenerative conditions. To follow this process, highly specific and photostable fluorescent probes are in demand. Commercially available mitochondria trackers, however, suffer from poor photostability. To overcome this limitation, we have designed and synthesized a fluorescent agent, tetraphenylethene-triphenylphosphonium (TPE-TPP), for mitochondrial imaging. Inherent from the mitochondrial-targeting ability of TPP groups and the aggregation-induced emission (AIE) characteristics of the TPE core, TPE-TPP possesses high specificity to mitochondria, superior photostability, and appreciable tolerance to environmental change, allowing imaging and tracking of the mitochondrial morphological changes in a long period of time.


Assuntos
Etilenos/química , Corantes Fluorescentes/química , Mitocôndrias/química , Compostos Organofosforados/química , Células HeLa , Humanos , Estrutura Molecular , Processos Fotoquímicos
12.
J Am Chem Soc ; 134(3): 1680-9, 2012 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-22191699

RESUMO

Amyloid fibrillation of proteins is associated with a great variety of pathologic conditions. Development of new molecules that can monitor amyloidosis kinetics and inhibit fibril formation is of great diagnostic and therapeutic value. In this work, we have developed a biocompatible molecule that functions as an ex situ monitor and an in situ inhibitor for protein fibrillation, using insulin as a model protein. 1,2-Bis[4-(3-sulfonatopropoxyl)phenyl]-1,2-diphenylethene salt (BSPOTPE) is nonemissive when it is dissolved with native insulin in an incubation buffer but starts to fluoresce when it is mixed with preformed insulin fibril, enabling ex situ monitoring of amyloidogenesis kinetics and high-contrast fluorescence imaging of protein fibrils. Premixing BSPOTPE with insulin, on the other hand, inhibits the nucleation process and impedes the protofibril formation. Increasing the dose of BSPOTPE boosts its inhibitory potency. Theoretical modeling using molecular dynamics simulations and docking reveals that BSPOTPE is prone to binding to partially unfolded insulin through hydrophobic interaction of the phenyl rings of BSPOTPE with the exposed hydrophobic residues of insulin. Such binding is assumed to have stabilized the partially unfolded insulin and obstructed the formation of the critical oligomeric species in the protein fibrillogenesis process.


Assuntos
Amiloide/antagonistas & inibidores , Amiloide/metabolismo , Insulina/metabolismo , Estilbenos/farmacologia , Amiloide/química , Amiloidose/diagnóstico , Animais , Bovinos , Insulina/química , Modelos Moleculares , Conformação Proteica , Espectrometria de Fluorescência
13.
ACS Appl Mater Interfaces ; 3(9): 3411-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21834577

RESUMO

Terpyridine-containing tetraphenylethenes (TPEs) are synthesized and their optical and metal sensing properties are investigated. They are practically nonluminescent in the solution state but become highly emissive as nanoparticle suspensions in poor solvents or thin films in the solid state, demonstrating a novel phenomenon of aggregation-induced emission (AIE). The emission of the nanoaggregates of TPEs is pH-sensitive: it is decreased and eventually quenched upon protonation of their terpyridine units because of their AIE nature. The TPEs can work as "turn-off" fluorescent chemosensors for metal ions and display different fluorescence responses to various metal ions. A characteristic red shift in the emission spectra is observed in the presence of Zn(2+), which facilitates the discrimination of Zn(2+) from other metal ions. Because of the metal-to-ligand-charge-transfer process, terpyridine-substituted TPEs display an obvious magenta color upon selectively binding with Fe(2+), allowing a rapid identification of Fe(2+) in the aqueous media by naked eyes.


Assuntos
Etilenos/química , Compostos Ferrosos/análise , Corantes Fluorescentes/química , Piridinas/química , Espectrofotometria Ultravioleta/métodos , Zinco/análise , Polimetil Metacrilato/química
14.
Anal Chem ; 82(16): 7035-43, 2010 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-20704392

RESUMO

Human serum albumin (HSA) is a major protein component of blood plasma, and its assay is of obvious value to biological research. We, herein, present a readily accessible fluorescent bioprobe for HSA detection and quantitation. A nonemissive tetraphenylethene derivative named sodium 1,2-bis[4-(3-sulfonatopropoxyl)phenyl]-1,2-diphenylethene (BSPOTPE) is induced to emit by HSA, showing a novel phenomenon of aggregation-induced emission (AIE). The AIE bioprobe enjoys a broad working range (0-100 nM), a low detection limit (down to 1 nM), and a superior selectivity to albumins. The fluorescent bioassay is unperturbed by the miscellaneous bioelectrolytes in the artificial urine. The AIE luminogen can also be used as a rapid and sensitive protein stain in gel electrophoresis for HSA visualization. Utilizing the AIE feature of BSPOTPE and the Forster resonance energy transfer from HSA to BSPOTPE, the unfolding process of HSA induced by guanidine hydrochloride is monitored, which reveals a multistep transition with the involvement of molten globule intermediates. Computational modeling suggests that the AIE luminogens dock in the hydrophobic cleft between subdomains IIA and IIIA of HSA with the aid of hydrophobic effect, charge neutralization, and hydrogen bonding interactions, offering mechanistic insight into the microenvironment inside the hydrophobic cavity.


Assuntos
Corantes Fluorescentes/química , Albumina Sérica/análise , Espectrometria de Fluorescência/métodos , Estilbenos/química , Eletroforese em Gel de Poliacrilamida , Transferência Ressonante de Energia de Fluorescência , Guanidina/química , Humanos , Desnaturação Proteica , Estrutura Terciária de Proteína , Albumina Sérica/química
15.
Chemistry ; 16(4): 1232-45, 2010 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-19957315

RESUMO

Whereas most conventional DNA probes are flat disklike aromatic molecules, we explored the possibility of developing quadruplex sensors with nonplanar conformations, in particular, the propeller-shaped tetraphenylethene (TPE) salts with aggregation-induced emission (AIE) characteristics. 1,1,2,2-Tetrakis[4-(2-triethylammonioethoxy)phenyl]ethene tetrabromide (TPE-1) was found to show a specific affinity to a particular quadruplex structure formed by a human telomeric DNA strand in the presence of K(+) ions, as indicated by the enhanced and bathochromically shifted emission of the AIE fluorogen. Steady-state and time-resolved spectral analyses revealed that the specific binding stems from a structural matching between the AIE fluorogen and the DNA strand in the folding process. Computational modeling suggests that the AIE molecule docks on the grooves of the quadruplex surface with the aid of electrostatic attraction. The binding preference of TPE-1 enables it to serve as a bioprobe for direct monitoring of cation-driven conformational transitions between the quadruplexes of various conformations, a job unachievable by the traditional G-quadruplex biosensors. Methyl thiazolyl tetrazolium (MTT) assays reveal that TPE-1 is cytocompatible, posing no toxicity to living cells.


Assuntos
DNA/química , Corantes Fluorescentes/química , Sequência de Bases , Sítios de Ligação , Técnicas Biossensoriais , Calorimetria , Simulação por Computador , Quadruplex G , Células HeLa , Humanos , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/toxicidade , Eletricidade Estática , Estilbenos/química , Estilbenos/toxicidade , Telômero/metabolismo , Termodinâmica
16.
Chemistry ; 15(10): 2328-34, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19156813

RESUMO

A chiral amino acid-containing polyacetylene, poly(4-ethynylbenzoyl-L-valine), was found to induce the aggregation and self-assembly of square-planar alkynylplatinum(II) terpyridyl complexes by electrostatic binding of the positively charged metal complexes to the anionic sites of the polyacetylene, as revealed by the appearance of new UV/Vis absorption and emission bands upon mixing under basic conditions. The induced complex self-assembly was found to be influenced by the polyacetylene and/or base concentration, and the effect of pH on the reversibility of the aggregate/monomer interconversion was also studied. The conformational changes of the polyacetylene were probed by circular dichroism (CD) spectroscopy, in which the chirality signal of the corresponding chain helicity in the presence of the base was enhanced and stabilized upon addition of the platinum(II) complexes. The induced complex aggregation was dependent on the structural properties of the polyacetylene, while the chirality of the polyacetylene was strongly influenced by the introduction of the complex.

17.
Chem Commun (Camb) ; (25): 2584-6, 2007 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-17579745

RESUMO

A cobalt-containing hyperbranched polydiyne shows refractive indexes (n) as high as 1.713-1.813 in the long wavelength region, which can be tuned to a large extent (Deltan up to approximately 0.048) by UV irradiation; the polymer can also function as a spin-coatable catalyst for the growth of carbon nanotubes.

18.
J Colloid Interface Sci ; 257(2): 263-7, 2003 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-16256479

RESUMO

A novel multilayer film was assembled from water-soluble poly(4-carboxyphenyl)acetylene sodium salt (PCPA) and diazoresin (DR) in aqueous solution via electrostatic attraction. Under UV irradiation, following the decomposition of the diazonium group between the adjacent interfaces of the multilayers, the ionic bonds of the self-assembled film convert to covalent bonds and the film becomes very stable toward electrolyte aqueous solutions. Thus, the photoelectric conversion property of PCPA-containing film can be measured in a conventional three-electrode photoelectrochemical cell, and 0.5 mol/l KCl solution can be used as the supporting electrolyte. The photocurrent spectroscopy response coincides with the absorption spectrum of the irradiated self-assembled film, which indicates that the irradiated DR/PCPA film is responsible for the photocurrent generation.

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