Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.875
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117329, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31326855

RESUMO

Visualization of membrane domains like lipid rafts in natural or artificial membranes is a crucial task for cell biology. For this purpose, fluorescence microscopy is often used. Since fluorescing probes in lipid membranes partition specifically in e.g. local liquid disordered or liquid ordered environments, the consequent changes in their orientation and location are both theoretically and experimentally of interest. Here we focused on a liquid disordered membrane phase and performed molecular dynamics (MD) simulations of the indocarbocyanine DiD probes by varying the length of the attached alkyl tails and also the length of the cyanine backbone. From the probed compounds in a DOPC lipid bilayer at ambient temperature, a varying orientation of the transition dipole moment was observed, which is crucial for fluorescence microscopy and which, through photoselection, was found to be surprisingly more effective for asymmetric probes than for the symmetric ones. Furthermore, we observed that the orientation of the probes was dependent on the tail length; with the methyls or propyls attached, DiD oriented with its tails facing the water, contrary to the ones with longer tails. With advanced hybrid QM/MM calculations we show that the different local environment for differently oriented probes affected the one-photon absorption spectra, that was blue-shifted for the short-tailed DiD with respect to the DiDs with longer tails. We show here that the presented probes can be successfully used for fluorescence microscopy and we believe that the described properties bring further insight for the experimental use of these probes.


Assuntos
Carbocianinas/química , Corantes Fluorescentes/química , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Simulação de Dinâmica Molecular , Espectrometria de Fluorescência
2.
Chem Commun (Camb) ; 56(5): 695-698, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31848532

RESUMO

In this work, a hydrazone chemistry assisted DNAzyme has been designed and constructed. The introduction of hydrazone chemistry increases the versatility of DNAzymes. With superior catalytic capability, the hydrazone chemistry assisted DNAzyme has been successfully applied for the analysis of double targets. Taking 5-hydroxymethylfurfural (HMF) and lipopolysaccharide (LPS) as samples, the hydrazone chemistry assisted DNAzyme can be used for the detection of different combinations of targets. Moreover, because hydrazone chemistry is popular in nature, this work may also provide a new insight for the development of DNAzymes and their multifunctionality.


Assuntos
DNA Catalítico/química , Hidrazonas/química , Carbocianinas/química , Catálise , Fluoresceínas/química , Corantes Fluorescentes/química , Furaldeído/análogos & derivados , Furaldeído/análise , Limite de Detecção , Lipopolissacarídeos/análise , Espectrometria de Fluorescência/métodos
3.
Chem Commun (Camb) ; 56(2): 213-216, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31808495

RESUMO

We developed a peptide-templated gold nanoparticle (AuNP) nanosensor for simultaneous detection of multiple posttranslational modification (PTM) enzymes with a detection limit of 28 pM for histone deacetylase (HDAC) and 0.8 pM for protein tyrosine phosphatase 1B (PTP1B), and it can be further applied for the screening of PTM enzyme inhibitors and the measurement of PTM enzymes in cancer cells.


Assuntos
Histona Desacetilases/análise , Nanopartículas Metálicas/química , Fosfopeptídeos/química , Proteína Tirosina Fosfatase não Receptora Tipo 1/análise , Carbocianinas/química , Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Ouro/química , Células HeLa , Inibidores de Histona Desacetilases/química , Histona Desacetilases/química , Humanos , Ácidos Hidroxâmicos/química , Limite de Detecção , Processamento de Proteína Pós-Traducional , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 1/química , Espectrometria de Fluorescência/métodos , Vanadatos/química
4.
Analyst ; 144(24): 7457-7462, 2019 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-31710053

RESUMO

Glutathione (GSH) plays crucial roles in various physiological and pathological processes. The fluctuation of the GSH level is closely associated with a variety of diseases and cellular functions. Hence, it is important to real-time monitor the fluctuation of GSH in living cells. In this work, we presented a rhodol-hybridized hemicyanine fluorophore (RdH) as a selective, rapid-response, ratiometric, and reversible fluorescent probe for intracellular GSH (t1/2 = 89 ms, Kd = 1.42 mM). The imaging assays in living cells revealed that RdH could be used to real-time monitor GSH dynamics in A549 cells under a laser scanning confocal microscope by ratiometric fluorescence changes.


Assuntos
Carbocianinas/química , Corantes Fluorescentes/química , Glutationa/metabolismo , Imagem Óptica , Xantonas/química , Células A549 , Humanos , Espectrometria de Fluorescência
5.
Chem Commun (Camb) ; 55(84): 12667-12670, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31584046

RESUMO

We have synthesized symmetrical carbocyanine dyes in which two 4-quinolinium rings are joined by a pentamethine bridge that is meso-substituted with H or Cl. Irradiation of the halogenated dye at 830 nm produces hydroxyl radicals that generate DNA direct strand breaks. This represents the first reported example of DNA photocleavage upon single photon excitation of a chromophore at wavelengths above 800 nm.


Assuntos
Carbocianinas/química , Clivagem do DNA/efeitos da radiação , DNA/química , Corantes Fluorescentes/química , Quinolinas/química , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Humanos , Radical Hidroxila/química , Raios Infravermelhos , Estrutura Molecular , Imagem Óptica , Processos Fotoquímicos , Fótons , Espectrometria de Fluorescência
6.
Chem Commun (Camb) ; 55(90): 13542-13545, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31647067
7.
Chem Commun (Camb) ; 55(88): 13223-13226, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31595909

RESUMO

There are a limited number of near-infrared (NIR) emitting (λem = 700-900 nm) molecular probes for imaging applications. A NIR-emitting probe that exhibits emission at ∼800 nm with a large Stokes shift was synthesized and found to exhibit excellent selectivity towards mitochondria for live-cell imaging. The photophysical properties were attributed to an excited "cyanine structure" via intramolecular charge transfer (ICT) involving a phenol group.


Assuntos
Carbocianinas/química , Fibroblastos/química , Corantes Fluorescentes/química , Oligodendroglia/química , Imagem Óptica , Fenóis/química , Linhagem Celular , Humanos , Raios Infravermelhos , Pulmão/citologia , Estrutura Molecular , Espectrometria de Fluorescência
8.
Analyst ; 144(21): 6254-6261, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31560359

RESUMO

As VEGF mRNA is an endothelial cell-specific mitogen and a key regulator of angiogenesis in a variety of physiological and pathological processes, high expression levels of VEGF messenger RNA (mRNA) contribute to VEGF-driven angiogenesis in the hypoxic areas of solid tumors and then disrupt the vascular barrier, which may potentiate tumor cell extravasation. Thus, monitoring the changes in VEGF mRNA is necessary to understand the genetic programme under hypoxic conditions and thus facilitate risk assessment and risk reduction in hypoxic environments. Herein, a new fluorescent nanoprobe based on azoreductase-responsive functional metal-organic frameworks (AMOFs) was developed to realize the imaging of VEGF mRNA under hypoxic conditions. Since the azobenzene units in the AMOFs can be reduced to amines by the highly expressed azoreductase in an oxygen-deficient environment, the VEGF mRNA-targeted molecular beacon (MB), which is adsorbed on the surface of AMOFs via electrostatic interactions, can be released due to the structural damage of AMOFs. Moreover, TAMRA (carboxytetramethylrhodamine, donor) and Cy5 (acceptor) were close to each other due to the stem-loop conformation of MB, thus inducing high fluorescence energy resonance transfer (FRET) efficiency. Upon the addition of VEGF mRNA, the hybridization of VEGF mRNA destroyed the stem-loop conformation of MB, and then, the two fluorophores labeled on MB were separated with low FRET efficiency. This constructed fluorescent nanoprobe enables the quantitative analysis and in situ imaging of the VEGF mRNA level in living cells under hypoxic conditions. We expect that it will offer a potentially rich opportunity to understand the physiological processes of genetic programme.


Assuntos
Hipóxia Celular/fisiologia , Corantes Fluorescentes/química , Estruturas Metalorgânicas/química , NADH NADPH Oxirredutases/química , RNA Mensageiro/análise , Fator A de Crescimento do Endotélio Vascular/genética , Carbocianinas/química , Peptídeos Penetradores de Células/síntese química , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/toxicidade , DNA/química , DNA/genética , Sondas de DNA/química , Sondas de DNA/genética , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células HeLa , Humanos , Estruturas Metalorgânicas/síntese química , Estruturas Metalorgânicas/toxicidade , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Hibridização de Ácido Nucleico , RNA Mensageiro/genética , Rodaminas/química
9.
Carbohydr Polym ; 224: 115174, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472852

RESUMO

The use of multifunctional quantum dots (QDs) as smart nanocarriers has exhibited substantial promise for imaging, targeting and therapeutic functionalities. Here, we describe the synthesis of green-light emitting CdZnSeS/ZnS quantum dots (QDs) combined with redox-sensitive hyaluronic acid ligand (hyaluronic acid-disulfide-linked poly(ethylene glycol)-histamine-diethylenetriamine, HA-PEG(SS)-His-Diet) for the targeted intracellular delivery of protein drugs. The generation of HA-PEG(SS)-His-Diet-QD exhibits monodispersity with high quantum yield, negligible cytotoxicity and long-term stability at pH 7.4 and 5.5. These HA-PEG(SS)-His-Diet-QDs could effectively immobilize cytochrome C (CC) with high loading efficiency, enable target of CD44-overexpressing MCF-7 human breast tumor cells, and accelerate protein release under high intracellular glutathione concentration condition. The HA-PEG(SS)-His-Diet-QD act as a promising nanocarrier for enhanced endo/lysosomal escape, targeted delivery of proteins and real-time cellular imaging. In addition, CC-loaded-HA-PEG(SS)-His-Diet-QD could effectively induce the CD44-positive cancer cells apoptosis in vitro. Ultimately, this redox-sensitive and fluorescent QD-based nanocarrier has shown major promise for targeted intracellular protein transport.


Assuntos
Citocromos c/química , Citocromos c/metabolismo , Portadores de Fármacos/química , Ácido Hialurônico/química , Espaço Intracelular/metabolismo , Imagem Óptica/métodos , Pontos Quânticos/química , Células A549 , Carbocianinas/química , Humanos , Células MCF-7 , Fatores de Tempo
10.
Anal Chim Acta ; 1080: 189-195, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31409469

RESUMO

Direct and absolute analysis of microRNAs (miRNAs) in complex media (e.g., human serum) is still a big challenge due to the issues with off-analyte absorption, low sensitivity and specificity. In this work, we have fabricated the erythrocyte membrane-biointerfaced spherical nucleic acids (EMSNAs) for miRNA assay, which not only enables tailor-engineered signal amplification but also exhibits anti-interference property. As a consequence, it is possible to achieve a single-step quantification of miRNAs in complex media without the process of enzymatic amplification, which can vastly simplify the detection procedure. Experimental results reveal that the assay permits ultrasensitive quantification of miR-141, with a limit of detection down to 33.9 aM, and show a high selectivity for discriminating miR-200 family members. More importantly, the assay enables robust miRNA analysis in human serum and can accurately differentiate lung cancer patients and prostate cancer patients from healthy donors. Its performance may satisfy the requirements for direct, rapid, sensitive and specific early diagnosis of cancer, signifying its great potential in clinical diagnostics.


Assuntos
Sondas de DNA/química , Membrana Eritrocítica/química , Corantes Fluorescentes/química , MicroRNAs/sangue , Animais , Carbocianinas/química , Sondas de DNA/genética , Ouro/química , Humanos , Limite de Detecção , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Masculino , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Nanoestruturas/química , Hibridização de Ácido Nucleico , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , Espectrometria de Fluorescência/métodos
11.
Photochem Photobiol Sci ; 18(10): 2461-2468, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31410432

RESUMO

Complexes of photosensitizers with blood proteins play an essential role in their delivery to the cell, as well as in the efficacy of photodynamic therapy. Biscarbocyanine dye non-covalently binds human serum albumin (HSA), the dissociation constant of the dye with albumin being Kd = (1.7 ± 0.1) × 10-5 M. According to time correlated single photon counting (TCSPC) fluorescence lifetime spectroscopy data, two types of complexes with lifetimes of 1.0 ns and 2.5 ns are formed between the dye and HSA. Confocal fluorescence microscopy has unambiguously shown the penetration of biscarbocyanine into endoplasmic reticulum, lysosomes, mitochondria and nuclei of the cells. The dye demonstrates photocytotoxicity towards the colon carcinoma HCT116 cells with IC50 = 0.3 µM. Hydrophobicity of the polymethine chain and the presence of two positive charges on the dye molecule contribute to the effective binding of the dye with HSA and the penetration into cells. These facts allow considering the biscarbocyanine dye as a promising agent for the photodynamic therapy of cancer.


Assuntos
Carbocianinas/química , Corantes Fluorescentes/química , Albumina Sérica/química , Carbocianinas/metabolismo , Carbocianinas/farmacologia , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Corantes Fluorescentes/metabolismo , Células HCT116 , Humanos , Lisossomos/metabolismo , Ligação Proteica , Albumina Sérica/metabolismo
12.
Anal Chim Acta ; 1081: 176-183, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31446955

RESUMO

Precise description of temperature at the microscale level is essential in many biological applications. In this study, we prepared a DNA-based thermometer that reports low and high temperatures by providing two distinct optical signals. The system is a molecular beacon that carries a loop and a stem, whose conformation is subject to change from a hairpin to a random coil when the temperature changes from low to high. A fluorophore, Cy5, and a quencher, BHQ3, are terminally labeled at the stem ends. Moreover, perylene is included in the middle of the 3'-end stem. The signaling state of Cy5 relies on the relative distance to BHQ3. However, the perylene emission is regulated by its microenvironment (i.e., the oligonucleotide or duplex state). With a temperature variation, the designed thermometer undergoes a change in conformation that leads to two signal patterns with Cy5/off and perylene/on at low temperature and Cy5/on and perylene/off at high temperature. The reversibility and biocompatibility of the thermometer design were examined for potential applications in biological systems.


Assuntos
Temperatura Baixa , DNA/química , Temperatura Alta , Termômetros , Carbocianinas/química , DNA/genética , Fluorescência , Corantes Fluorescentes/química , Células Hep G2 , Humanos , Sequências Repetidas Invertidas , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/genética , Concentração Osmolar , Perileno/química
13.
Talanta ; 205: 120125, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31450407

RESUMO

The precise detection of endogenous biothiols such as Glutathione (GSH), Cysteine (Cys) and Homocysteine (HCy) is a long-standing human health concern. A dual-channel fluorescent probe (Cy-DC) composed of two fluorescence reporting units (dicyanomethylene-4H-pyran and cyanine) with ether linker for distinguishing different endogenous biothiols was designed and synthesized. Due to the two well-resolved emission bands, this probe possesses an outstanding capability for selectively sensing of endogenous GSH spatiotemporally and synchronously. Nevertheless, in the near infrared (NIR) channel (λex = 700 nm, λem = 810 nm), the probe can produce strong fluorescence only when it responds to GSH. Besides, the cells (L02 and U87) imaging, it also demonstrated that Cy-DC could successfully discriminate between GSH and Cys/Hcy with high sensitivity with the limit of detection (LOD) is 24 nM and 32 nM (3*SD/K). Particularly, the probe was applied in detecting solid tumor by the naked-eye and NIR imaging successfully, which revealed that the probe has promising prospects in clinical diagnosis applications.


Assuntos
Corantes Fluorescentes/química , Glutationa/metabolismo , Raios Infravermelhos , Mitocôndrias/metabolismo , Compostos de Sulfidrila/química , Animais , Carbocianinas/química , Linhagem Celular Tumoral , Sobrevivência Celular , Corantes Fluorescentes/metabolismo , Corantes Fluorescentes/farmacocinética , Humanos , Limite de Detecção , Camundongos , Piranos/química , Espectrometria de Fluorescência , Distribuição Tecidual
14.
Talanta ; 205: 120133, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31450408

RESUMO

Timely and effective detection of bacterial pathogens is of great importance to reduce morbidity rates from bacterial infections. Recently, enzyme-activated fluorogenic probes, which invoke enzymatic catalysis to trigger fluorescence emission, have been superior sensors for bacterial infections needed for accurate diagnoses. Here, a fluorescent sensor for nitroreductase (NTR) detection is described. It is based on a cyanine fluorophore and utilizes photoinduced electron transfer to generate a rapid 10-fold fluorescence response after being catalytically reduced by NTR. It has enabled selective and sensitive visualization of NTR activity in vitro and in living bacterial pathogens. Thus, the probe has great potential to provide a rapid, noninvasive tool to diagnose infections and guide antimicrobial selection.


Assuntos
Nitrorredutases/metabolismo , Imagem Óptica , Processos Fotoquímicos , Espectrometria de Fluorescência/instrumentação , Carbocianinas/química , Transporte de Elétrons , Concentração de Íons de Hidrogênio , Staphylococcus aureus Resistente à Meticilina/metabolismo , Nitrorredutases/antagonistas & inibidores , Temperatura Ambiente
15.
Int J Mol Sci ; 20(17)2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466233

RESUMO

Cancer cells preferentially utilize glycolysis for ATP production even in aerobic conditions (the Warburg effect) and adapt mitochondrial processes to their specific needs. Recent studies indicate that altered mitochondrial activities in cancer represent an actionable target for therapy. We previously showed that salt 1-3C, a quinoxaline unit (with cytotoxic activity) incorporated into a meso-substituted pentamethinium salt (with mitochondrial selectivity and fluorescence properties), displayed potent cytotoxic effects in vitro and in vivo, without significant toxic effects to normal tissues. Here, we investigated the cytotoxic mechanism of salt 1-3C compared to its analogue, salt 1-8C, with an extended side carbon chain. Live cell imaging demonstrated that salt 1-3C, but not 1-8C, is rapidly incorporated into mitochondria, correlating with increased cytotoxicity of salt 1-3C. The accumulation in mitochondria led to their fragmentation and loss of function, accompanied by increased autophagy/mitophagy. Salt 1-3C preferentially activated AMP-activated kinase and inhibited mammalian target of rapamycin (mTOR) signaling pathways, sensors of cellular metabolism, but did not induce apoptosis. These data indicate that salt 1-3C cytotoxicity involves mitochondrial perturbation and disintegration, and such compounds are promising candidates for targeting mitochondria as a weak spot of cancer.


Assuntos
Antineoplásicos/farmacologia , Mitocôndrias/efeitos dos fármacos , Compostos de Amônio Quaternário/farmacologia , Quinazolinas/farmacologia , Antineoplásicos/química , Carbocianinas/química , Linhagem Celular Tumoral , Humanos , Mitocôndrias/metabolismo , Proteínas Quinases/metabolismo , Compostos de Amônio Quaternário/química , Quinazolinas/química , Serina-Treonina Quinases TOR/metabolismo
16.
Sensors (Basel) ; 19(16)2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31405068

RESUMO

Sensitive detection of nucleic acids and identification of single nucleotide polymorphism (SNP) is crucial in diagnosis of genetic diseases. Many strategies have been developed for detection and analysis of DNA, including fluorescence, electrical, optical, and mechanical methods. Recent advances in fluorescence resonance energy transfer (FRET)-based sensing have provided a new avenue for sensitive and quantitative detection of various types of biomolecules in simple, rapid, and recyclable platforms. Here, we report single-step FRET-based DNA sensors designed to work via a toehold-mediated strand displacement (TMSD) process, leading to a distinct change in the FRET efficiency upon target binding. Using single-molecule FRET (smFRET), we show that these sensors can be regenerated in situ, and they allow detection of femtomoles DNA without the need for target amplification while still using a dramatically small sample size (fewer than three orders of magnitude compared to the typical sample size of bulk fluorescence). In addition, these single-molecule sensors exhibit a dynamic range of approximately two orders of magnitude. Using one of the sensors, we demonstrate that the single-base mismatch sequence can be discriminated from a fully matched DNA target, showing a high specificity of the method. These sensors with simple and recyclable design, sensitive detection of DNA, and the ability to discriminate single-base mismatch sequences may find applications in quantitative analysis of nucleic acid biomarkers.


Assuntos
DNA/análise , Transferência Ressonante de Energia de Fluorescência/métodos , Carbocianinas/química , Corantes Fluorescentes/química , Limite de Detecção , Polimorfismo de Nucleotídeo Único
17.
Eur J Histochem ; 63(3)2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31455073

RESUMO

RNA interference is a powerful approach to understand gene function both for therapeutic and experimental purposes. Since the lack of knowledge in the gene silencing of various hepatic cell lines, this work was aimed to compare two transfection agents, the liposome-based Lipofectamine™ RNAiMAX and the HepG2-specific, polymer-based GenMute™, in two cellular models of human hepatoma, HepG2 and Huh7.5. In the first part, we assessed transfection efficiency of a fluorescent Cy3-labeled negative control siRNA by cell imaging analysis; we found that cells treated with GenMute present a higher uptake of the fluorescent negative control siRNA when compared to Lipofectamine RNAiMAX-transfected cells, both in HepG2 and in Huh7.5 cells. In the second part, we evaluated GAPDH silencing with the two transfection reagents by RT-PCR similar GAPDH mRNA expression after each transfection treatment. Finally, we measured cell viability by the MTT assay, observing that cells transfected with GenMute have higher viability with respect to Lipofectamine RNAiMAX-administered cells. These results suggest that GenMute reagent might be considered the most suitable transfection agent for hepatic gene silencing.


Assuntos
Técnicas de Transferência de Genes , Lipídeos/química , Polímeros/química , RNA Interferente Pequeno/genética , Transfecção/métodos , Sequência de Bases , Carbocianinas/química , Carbocianinas/metabolismo , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Inativação Gênica , Gliceraldeído-3-Fosfato Desidrogenases/genética , Humanos , Metabolismo dos Lipídeos , Lipídeos/toxicidade , Lipossomos/química , Lipossomos/metabolismo , Lipossomos/toxicidade , Neoplasias Hepáticas/genética , Polímeros/metabolismo , Polímeros/toxicidade , Interferência de RNA
18.
ACS Appl Mater Interfaces ; 11(34): 31302-31310, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31369228

RESUMO

A detailed understanding of the cellular uptake and trafficking of nanomaterials is essential for the design of "smart" intracellular drug delivery vehicles. Typically, cellular interactions can be tailored by endowing materials with specific properties, for example, through the introduction of charges or targeting groups. In this study, water-soluble carboxylated N-acylated poly(amino ester)-based comb polymers of different degree of polymerization and side-chain modification were synthesized via a combination of spontaneous zwitterionic copolymerization and redox-initiated reversible addition-fragmentation chain-transfer polymerization and fully characterized by 1H NMR spectroscopy and size exclusion chromatography. The comb polymers showed no cell toxicity against NIH/3T3 and N27 cell lines nor hemolysis. Detailed cellular association and uptake studies by flow cytometry and confocal laser scanning microscopy (CLSM) revealed that the carboxylated polymers were capable of passively diffusing cell membranes and targeting mitochondria. The interplay of pendant carboxylic acids of the comb polymers and the Cy5-label was identified as major driving force for this behavior, which was demonstrated to be applicable in NIH/3T3 and N27 cell lines. Blocking of the carboxylic acids through modification with 2-methoxyethylamine and poly(2-ethyl-2-oxazoline) or replacement of the dye label with a different dye (e.g., fluorescein) resulted in an alteration of the cellular uptake mechanism toward endocytosis as demonstrated by CLSM. In contrast, partial modification of the carboxylic acid groups allowed to retain the cellular interaction, hence, rendering these comb polymers a highly functional mitochondria targeted carrier platform for future drug delivery applications and imaging purposes.


Assuntos
Carbocianinas , Membrana Celular/metabolismo , Portadores de Fármacos , Mitocôndrias/metabolismo , Polímeros , Animais , Carbocianinas/química , Carbocianinas/farmacocinética , Carbocianinas/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Endocitose , Citometria de Fluxo , Camundongos , Microscopia Confocal , Células NIH 3T3 , Polímeros/química , Polímeros/farmacocinética , Polímeros/farmacologia , Ratos
19.
ACS Appl Mater Interfaces ; 11(37): 33628-33636, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31433160

RESUMO

The multifunctional effect of a single molecule for therapeutic functionalities on a single theranostic nanosystem has a great significance to enhance the accuracy of diagnosis and improve the efficacy of therapy. Herein, a biocompatible multistep phototherapeutic system (Ppa-Cy7-PEG-biotin) that contains a photosensitizer pyropheophorbide A (Ppa) with the covalent conjunction of a near-infrared (NIR) cyanine dye (Cy7) was successfully fabricated and functionalized with biotin for flexible specific tumor-targeting phototherapy. These theranostic micelles will disaggregate after NIR irradiation via the photodegradation of cyanine accompanied by the photothermal conversion and the optically controlled release for the restoration of photodynamic function of quenched Ppa. Consecutively, promoted treatments of photosensitive molecules greatly prolonged the tumor retention time and treatment efficiency, having a multistep antitumor effect both in vitro and in vivo. Different from the simple phototherapeutic configurations that only act on the superficial areas of tumors at mild doses, the multistep therapy can be competent for broadly damaging the superficial and deeper regions of tumors at the same dose. Therefore, as opposed to the general combination phototherapeutic approach, this strategy presents a photoactivation-based multistep phototheranostic platform with an enormous potential in enhanced combined phototherapy for cancer.


Assuntos
Carbocianinas , Micelas , Nanopartículas , Neoplasias Experimentais/terapia , Fototerapia , Radiossensibilizantes , Células A549 , Animais , Carbocianinas/química , Carbocianinas/farmacologia , Células Hep G2 , Humanos , Camundongos , Camundongos Nus , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Radiossensibilizantes/química , Radiossensibilizantes/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Analyst ; 144(15): 4545-4551, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31268085

RESUMO

Sialic acid (SA), usually located at the termini of glycan chains, is one of the most important monosaccharide blocks for glycosylation of proteins. The expression level of sialoglycoconjugates (SiaGCs) in cellular secretome is of great significance in diagnosis of tumor malignancy. This work developed a fluorescent visual method for the detection of SiaGCs secreted from living cells by a boronic acid modified chip based chemoselective recognition and hybridization chain reaction. The cell-secreted SiaGCs, which were labeled with the azide group through a metabolic labeling technique during cell culture, were captured by the chip through chemoselective recognition of boronic acid toward SA. After further conjugating the azide group with an alkyne modified DNA probe, the captured SiaGCs could be conveniently endowed with the amplified fluorescent signal through a hybridization chain reaction of a pair of dye-labeled DNA hairpins, which led to a quantitative imaging method for detection of SiaGCs. The average amount of metabolically labeled SiaGCs secreted from a single HeLa cell and MCF-7 cell was 2.18 × 10-17 and 3.98 × 10-17 mol, respectively. The proposed method could be utilized to monitor the variation of the secreted SiaGCs during drug treatment, providing a useful tool for investigating the glycosylation and glycan-related biological processes.


Assuntos
Fluorometria/métodos , Glicoconjugados/análise , Alquinos/química , Azidas/química , Azidas/metabolismo , Ácidos Borônicos/química , Carbocianinas/química , Linhagem Celular Tumoral , DNA/química , DNA/genética , Sondas de DNA/química , Sondas de DNA/genética , Corantes Fluorescentes/química , Glicoconjugados/química , Hexosaminas/química , Hexosaminas/metabolismo , Humanos , Ácido N-Acetilneuramínico/química , Técnicas de Amplificação de Ácido Nucleico/métodos , Hibridização de Ácido Nucleico , Compostos de Sulfidrila/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA