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1.
Anal Chem ; 91(3): 2021-2027, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30638008

RESUMO

Gold nanoparticles (AuNPs) have shown great promise as a universal platform for biosensing and are often functionalized with a densely packed DNA for intracellular detection. While DNA-AuNP conjugates, such as nanoflares, have been used for single and multiple mRNA molecules detection in living cells, the target recognition reaction is triggered once they enter into cells, making it impossible to control the initial reaction at the desired time. To solve this problem, we have designed photoactivated (PA) nanoflares for intracellular mRNA analysis with high spatiotemporal control. PA nanoflares consist of AuNP and photoresponsive DNA hairpin probes. Without UV irradiation, the DNA hairpin could be kept unawakened and show no reactivity to target the probe. Upon UV activation, the hairpin structures are destroyed and expose the sticky domains, which act as toeholds to mediate strand displacement reactions, making flares release from the gold surface and causing an increase of fluorescence. By tuning light irradiation, PA nanoflares for mRNA detection in living cells can be temporally controlled. With the benefit from two-photon laser illumination, PA nanoflares can detect mRNA in selective cells at a desired time point at the single-cell level. Compared to the traditional nanoflares, the novel PA nanoflares have increased the detection sensitivity and achieved intracellular biomarkers detection at the single-cell level with high spatiotemporal control.

2.
Nano Lett ; 19(1): 618-625, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30585496

RESUMO

The spatially defined functionalization of microparticles with asymmetric shape-controlled nucleic acid patterns is a major challenge in materials science. The asymmetric patterning of microparticles is important to allow the controlled fabrication of crystalline lattices or controlled aggregates of microparticles. We present the combination of two-photon lithography and photocleavable o-nitrobenzylphosphate ester nucleic acid coating-modified microparticles as a versatile means to asymmetrically pattern single microparticle surfaces. The two-photon patterning of microparticles with predesigned nucleic acid structures of different sizes (700 nm to 2.8 µm) and shapes (circles, rings, triangles, and squares) are demonstrated. In addition, complex patterned domains consisting of two different asymmetric nucleic acid domains are fabricated by the controlled Z-positioning of the microparticles in respect to the two-photon irradiation sources. In addition, the two-photon lithographic patterning of the photocleavable DNA coating allows the generation of functional nucleic acid domains for the photostimulated activation of the catalytic hybridization assembly (CHA) of branched nucleic acid structures on single microparticles.

3.
Anal Bioanal Chem ; 2018 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-30415403

RESUMO

A superamphiphobic surface composed of two different size ranges of TiO2 nanoparticles was simply fabricated through spraying the perfluorosilane coated TiO2 nanoparticles suspension dispersing in ethanol. The surface chemistry was finely regulated through gradient UV irradiation-induced organic compound degradation to fabricate surface with gradient solid surface energy or wettability. The fabricated surface shows good droplet sorting ability, which can successfully discriminate ethanol droplets with different concentrations. As a proof-of-concept, the biosensor application of this surface was demonstrated by using it for naked-eye ATP detection. Liquid droplets with different concentrations of ATP after ATP-dependent rolling circle amplification (RCA) can be effectively sorted by the surface. This developed biosensor methodology based on droplet sorting ability of the fabricated surface is energy-efficient and economical which is promising for biosensors, point-of-care testing, and biochemical assays. Graphical abstract ᅟ.

4.
Nano Lett ; 18(8): 5116-5123, 2018 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-29998736

RESUMO

The spatiotemporal detection of a target mRNA in a single living cell is a major challenge in nanoscience and nanomedicine. We introduce a versatile method to detect mRNA at a single living cell level that uses photocleavable hairpin probes as functional units for the optical (fluorescent) and electrochemical (voltammetric) detection of MnSOD mRNA in single MCF-7 cancer cells. The fluorescent probe is composed of an ortho-nitrophenylphosphate ester functionalized hairpin that includes the FAM fluorophore in a caged configuration quenched by Dabcyl. The fluorescent probe is further modified with the AS1411 aptamer to facilitate the targeting and internalization of the probe into the MCF-7 cells. Under UV irradiation, the hairpin is cleaved, leading to the intracellular mRNA toehold-stimulated displacement of the FAM-functionalized strand resulting in a switched-on fluorescence signal upon the detection of the mRNA in a single cell. In addition, a nanoelectrode functionalized with a methylene blue (MB) redox-active photocleavable hairpin is inserted into the cytoplasm of a single MCF-7 cell. Photocleavage of the hairpin leads to the mRNA-mediated toehold displacement of the redox-active strand associated with the probe, leading to the depletion of the voltammetric response of the probe. The parallel optical and electrochemical detection of the mRNA at a single cell level is demonstrated.

5.
Nanoscale ; 9(9): 2981-2985, 2017 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-28225119

RESUMO

A DNA photonic nanowire with tunable FRET signals was fabricated on the basis of cascaded toehold-mediated DNA strand displacement reactions. Different DNA inputs were added to trigger the reaction network, and the corresponding FRET signals were obtained. Compared to the direct hybridization, this design is sensitive for 2 nM targets within 20 min and also causes color changes of the solution with blue-light excitation. It could also be applied in live cells to monitor MicroRNA with a simple modification which might become a low-cost method for further application in the future.


Assuntos
DNA/química , Transferência Ressonante de Energia de Fluorescência , Nanofios , Hibridização de Ácido Nucleico , Fótons
6.
J Am Chem Soc ; 138(49): 16112-16119, 2016 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-27960351

RESUMO

We present the assembly of asymmetric two-layer hybrid DNA-based hydrogels revealing stimuli-triggered reversibly modulated shape transitions. Asymmetric, linear hydrogels that include layer-selective switchable stimuli-responsive elements that control the hydrogel stiffness are designed. Trigger-induced stress in one of the layers results in the bending of the linear hybrid structure, thereby minimizing the elastic free energy of the systems. The removal of the stress by a counter-trigger restores the original linear bilayer hydrogel. The stiffness of the DNA hydrogel layers is controlled by thermal, pH (i-motif), K+ ion/crown ether (G-quadruplexes), chemical (pH-doped polyaniline), or biocatalytic (glucose oxidase/urease) triggers. A theoretical model relating the experimental bending radius of curvatures of the hydrogels with the Young's moduli and geometrical parameters of the hydrogels is provided. Promising applications of shape-regulated stimuli-responsive asymmetric hydrogels include their use as valves, actuators, sensors, and drug delivery devices.


Assuntos
DNA/química , Hidrogéis/química , Compostos de Anilina/química , Éteres de Coroa/química , Quadruplex G , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Concentração de Íons de Hidrogênio , Modelos Moleculares , Potássio/química , Estresse Mecânico , Termodinâmica , Urease/química , Urease/metabolismo
10.
Anal Chem ; 88(17): 8913-9, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27503607

RESUMO

Controlled drug delivery and real-time tracking of drug release in cancer cells are essential for cancer therapy. Herein, we report a protease-responsive prodrug (DOX-FCPPs-PyTPE, DFP) with aggregation-induced emission (AIE) characteristics for controlled drug delivery and precise tracking of drug release in living cells. DFP consists of three components: AIE-active tetraphenylethene (TPE) derivative PyTPE, functionalized cell penetrating peptides (FCPPs) containing a cell penetrating peptide (CPP) and a short protease-responsive peptide (LGLAG) that can be selectively cleaved by a cancer-related enzyme matrix metalloproteinase-2 (MMP-2), and a therapeutic unit (doxorubicin, DOX). Without MMP-2, this prodrug cannot go inside the cells easily. In the presence of MMP-2, DFP can be cleaved into two parts. One is cell penetrating peptides (CPPs) linked DOX, which can easily interact with cell membrane and then go inside the cell with the help of CPPs. Another is the PyTPE modified peptide which will self-aggregate because of the hydrophobic interaction and turn on the yellow fluorescence of PyTPE. The appearance of the yellow fluorescence indicates the release of the therapeutic unit to the cells. The selective delivery of the drug to the MMP-2 positive cells was also confirmed by using the intrinsic red fluorescence of DOX. Our result suggests a new and promising method for controlled drug delivery and real-time tracking of drug release in MMP-2 overexpression cells.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Corantes Fluorescentes/química , Metaloproteinase 2 da Matriz/metabolismo , Pró-Fármacos/farmacologia , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/metabolismo , Relação Dose-Resposta a Droga , Doxorrubicina/química , Doxorrubicina/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Corantes Fluorescentes/metabolismo , Humanos , Microscopia Confocal , Pró-Fármacos/química , Pró-Fármacos/metabolismo , Estilbenos/química , Estilbenos/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
11.
J Am Chem Soc ; 138(28): 8936-45, 2016 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-27309888

RESUMO

A method to assemble light-responsive or pH-responsive microcapsules loaded with different loads (tetramethylrhodamine-modified dextran, TMR-D; microperoxidase-11, MP-11; CdSe/ZnS quantum dots; or doxorubicin-modified dextran, DOX-D) is described. The method is based on the layer-by-layer deposition of sequence-specific nucleic acids on poly(allylamine hydrochloride)-functionalized CaCO3 core microparticles, loaded with the different loads, that after the dissolution of the core particles with EDTA yields the stimuli-responsive microcapsules that include the respective loads. The light-responsive microcapsules are composed of photocleavable o-nitrobenzyl-phosphate-modified DNA shells, and the pH-responsive microcapsules are made of a cytosine-rich layer cross-linked by nucleic acid bridges. Irradiating the o-nitrobenzyl phosphate-functionalized microcapsules, λ = 365 nm, or subjecting the pH-responsive microcapsules to pH = 5.0, results in the cleavage of the microcapsule shells and the release of the loads. Preliminary studies address the cytotoxicity of the DOX-D-loaded microcapsules toward MDA-MB-231 breast cancer cells and normal MCF-10A breast epithelial cells. Selective cytotoxicity of the DOX-D-loaded microcapsules toward cancer cells is demonstrated.


Assuntos
DNA/química , Doxorrubicina/química , Portadores de Fármacos/química , Luz , Transporte Biológico , Carbonato de Cálcio/química , Cápsulas , Linhagem Celular Tumoral , Preparações de Ação Retardada , Portadores de Fármacos/metabolismo , Liberação Controlada de Fármacos , Ácido Edético/química , Humanos , Concentração de Íons de Hidrogênio
12.
ACS Appl Mater Interfaces ; 8(14): 8998-9003, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-27011025

RESUMO

Enzyme-assisted detection strategies of microRNAs (miRNAs) in vitro have accomplished both great sensitivity and specificity. However, low expression of miRNAs and a complex environment in cells induces big challenges for monitoring and tracking miRNAs in vivo. The work reports the attempt to carry miRNA imaging into live cells, by enzyme-aided recycling amplification. We utilize facile probes based yellow aggregation-induced emission luminogens (AIEgens) with super photostable property but without quencher, which are applied to monitor miRNAs not only from urine sample extracts (in vitro) but also in live cells (in vivo). The assay could distinguish the cancer patients' urine samples from the healthy urine due to the good specificity. Moreover, the probe showed much higher fluorescence intensity in breast cancer cells (MCF-7) (miR-21 in high expression) than that in cervical cancer cells (HeLa) and human lung fibroblast cells (HLF) (miR-21 in low expression) in more than 60 min, which showed the good performance and super photostability for the probe in vivo. As controls, another two probes with FAM/Cy3 and corresponding quenchers, respectively, could perform miRNAs detections in vitro and parts of in vivo tests but were not suitable for the long-term cell tracking due to the photobleach phenomena, which also demonstrates that the probe with AIEgens is a potential candidate for the accurate identification of cancer biomarkers.


Assuntos
Biomarcadores Tumorais/urina , MicroRNAs/urina , Imagem Molecular/métodos , Neoplasias/urina , Exodesoxirribonucleases/química , Humanos , Células MCF-7 , MicroRNAs/genética , Neoplasias/genética
13.
Anal Chem ; 88(6): 3289-94, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26867868

RESUMO

In situ detecting and monitoring intracellular telomerase activity is significant for cancer diagnosis. In this work, we report a facile and fast-responsive bioprobe for in situ detection and imaging of intracellular telomerase activity with superior photostability. After transfected into living cells, quencher group labeled TS primer (QP) can be extended in the presence of intracellular telomerase. Positive charged TPE-Py molecules (AIE dye) will bind to the primer as well as extension repeated units, producing a telomerase activity-related turn-on fluorescence signal. By incorporating positive charged AIE dye and substrate oligonucleotides, in situ light-up imaging and detection of intracellular telomerase activity were achieved. This strategy exhibits good performance for sensitive in situ tracking of telomerase activity in living cells. The practicality of this facile and fast-responsive telomerase detection method was demonstrated by using it to distinguish tumor cells from normal cells and to monitor the change of telomerase activity during treatment with antitumor drugs, which shows its potential in clinical diagnostic and therapeutic monitoring.


Assuntos
Telomerase/metabolismo , Linhagem Celular , Fluorescência , Humanos
14.
Nanotechnology ; 26(42): 425601, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26421440

RESUMO

In this work, two DNA nanodevices were constructed utilizing a DNA strand displacement reaction. With the assistance of gold nanoparticles (AuNPs) and gold nanorods (AuNRs), the autonomous reactions can be reflected from the aggregation states of nanoparticles. By sequence design and the two non-overlapping double hump-like UV-vis spectral peaks of AuNPs and AuNRs, two logic gates with multiple inputs and outputs were successfully run with expected outcomes. This method not only shows how to achieve computing with multiple logic calculations but also has great potential for multiple targets detection.


Assuntos
DNA/química , Ouro/química , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Computadores Moleculares , Lógica
15.
J Am Chem Soc ; 137(44): 14107-13, 2015 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-26485090

RESUMO

Programmable and algorithmic behaviors of DNA molecules allow one to control the structures of DNA-assembled materials with nanometer precision and to construct complex networks with digital and analog behaviors. Here we developed a way of integrating a DNA-strand-displacement circuit with self-assembly of spherical nucleic acids, wherein a single DNA strand was used to initiate and catalyze the operation of upstream circuits to release a single strand that subsequently triggers self-assembly of spherical nucleic acids in downstream circuits, realizing a programmable kinetic control of self-assembly of spherical nucleic acids. Through utilizing this method, single-nucleotide polymorphisms or indels occurring at different positions of a sequence of oligonucleotide were unambiguously discriminated. We provide here a sophisticated way of combining the DNA-strand-displacement-based characteristic of DNA with the distinct assembly properties of inorganic nanoparticles, which may find broad potential applications in the fabrication of a wide range of complex multicomponent devices and architectures.


Assuntos
DNA de Cadeia Simples/química , Conformação de Ácido Nucleico , Algoritmos , DNA de Cadeia Simples/síntese química , Humanos , Cinética , Polimorfismo de Nucleotídeo Único
16.
Small ; 11(43): 5800-6, 2015 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-26382921

RESUMO

The fabrication of DNA polymer brushes with spatial resolution onto a solid surface is a crucial step for biochip research and related applications, cell-free gene expression study, and even artificial cell fabrication. Here, for the first time, a DNA polymer brush patterning method is reported based on the photoactivation of an ortho-nitrobenzyl linker-embedded DNA hairpin structure and a subsequent surface-initiated DNA hybridization chain reaction (HCR). Inert DNA hairpins are exposed to ultraviolet light irradiation to generate DNA duplexes with two active sticky ends (toeholds) in a programmable manner. These activated DNA duplexes can initiate DNA HCR to generate multifunctional patterned DNA polymer brushes with complex geometrical shapes. Different multifunctional DNA polymer brush patterns can be fabricated on certain areas of the same solid surface using this method. Moreover, the patterned DNA brush surface can be used to capture target molecules in a desired manner.


Assuntos
Sondas de DNA/síntese química , DNA/química , Hibridização In Situ/métodos , Impressão Molecular/métodos , Polímeros/química , Adsorção , DNA/genética , DNA/efeitos da radiação , Sondas de DNA/genética , Sondas de DNA/efeitos da radiação , Luz , Teste de Materiais , Fotoquímica/métodos , Propriedades de Superfície/efeitos da radiação
17.
Langmuir ; 31(25): 7055-61, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26057346

RESUMO

In DNA dynamic nanotechnology, a toehold-mediated DNA strand-displacement reaction has demonstrated its capability in building complex autonomous system. In most cases, the reaction is performed in pure DNA solution that is essentially a one-phase system. In the present work, we systematically investigated the reaction in a heterogeneous media, in which the strand that implements a displacing action is conjugated on gold nanoparticles. By monitoring the kinetics of spherical nucleic acid (SNA) assembly driven by toehold-mediated strand displacement reaction, we observed significant differences, i.e., the abrupt jump in behavior of an "off/on switch", in the reaction rate when the invading toehold was extended to eight bases from seven bases. These phenomena are attributed to the effect of steric hindrance arising from the high density of invading strand conjugated to AuNPs. Based on these studies, an INHIBIT logic gate presenting good selectivity was developed.


Assuntos
DNA/química , Ouro/química , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Computadores Moleculares , Cinética , Lógica , Prata/análise , Propriedades de Superfície
18.
Colloids Surf B Biointerfaces ; 123: 892-9, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25466461

RESUMO

Dual polarization interferometry was used to monitor the immobilization dynamics of four Pluronics on hydrophobic surfaces and to elucidate the effect of Pluronic conformation on protein adsorption. The proportion of hydrophobic chain segments and not the length of the hydrophobic chain can influence the chain densities of the Pluronics. The immobilized densities of the Pluronics resulted from competition between the hydration of polyethylene oxide (PEO) in the aqueous solution and the hydrophobic interaction of polypropylene oxide on the substrate. P-123 obtained the largest graft mass (2.89±0.25 ng/mm2) because of the dominant effect of hydrophobic interactions. Hydrophobic segments of P-123 were anchored slowly and step-wise on the C18 substrate. P-123 exhibited the largest hydrophobic chain segment proportion (propylene oxide/ethylene oxide=3.63) and formed a brush chain conformation, indicating excellent protein and platelet resistance. The result of quartz crystal microbalance with dissipation further confirmed that the PEO conformation in P-123 on the substrate exhibited a relatively extended brush chain, and that L-35 showed relatively loose and pancake-like structures. The PEO in P-123 regulated the conformation to maintain the native conformation and resist the adsorption of bovine serum albumin (BSA). Thus, the hemocompatibilities of the immobilized Pluronics were influenced by the proportion of hydrophobic chain segments and their PEO conformations.


Assuntos
Polietilenoglicóis/química , Polímeros/química , Propilenoglicóis/química , Animais , Plaquetas/efeitos dos fármacos , Bovinos , Interações Hidrofóbicas e Hidrofílicas , Adesividade Plaquetária/efeitos dos fármacos , Poloxâmero , Polietilenoglicóis/efeitos adversos , Polímeros/efeitos adversos , Propilenoglicóis/efeitos adversos , Soroalbumina Bovina/efeitos dos fármacos
19.
Chem Commun (Camb) ; 50(91): 14171-4, 2014 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-25277154

RESUMO

In this study, a single-base change discrimination strategy was developed through enhanced DNA toehold exchange reaction on a chip surface. A DNA strand with single-base change (SNPs, insertion or deletion) at an arbitrary position was clearly discriminated with nucleic acid concentrations from 0.8 nM to 1 µM through this method.


Assuntos
DNA/análise , Sondas de DNA/química , Propriedades de Superfície
20.
Adv Mater ; 26(35): 6181-5, 2014 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-25066311

RESUMO

A new strategy for single-base polymorphism (SNP) detection based on the assembly of DNA-AuNPs (gold nanoparticles) driven by a DNA-fueled molecular machine, is established and optimized. It is highly efficient, works at room temperature, and is easy to handle. A single-base change on an oligonucleotide strand is unambiguously discriminated for either SNPs or insertions and deletions (indels). The strategy is demonstrated to detect a mutation in the breast cancer gene BRCA1 in homogeneous solution at room temperature.


Assuntos
DNA/química , Ouro/química , Nanopartículas Metálicas/química , Proteína BRCA1/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Catálise , Feminino , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único , Espectrofotometria Ultravioleta
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