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1.
Anal Chem ; 93(36): 12329-12336, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34474564

RESUMO

"On-demand" accurate imaging of multiple intracellular miRNAs will significantly improve the detection reliability and accuracy. However, the "always-active" design of traditional multicomponent detection probes enables them to passively recognize and output signals as soon as they encounter targets, which will inevitably impair the detection accuracy and, inevitably, result in false-positive signals. To address this scientific problem, in this work, we developed a near-infrared (NIR) light-activated multicomponent detection intelligent nanoprobe for spatially and temporally controlled on-demand accurate imaging of multiple intracellular miRNAs. The proposed intelligent nanoprobe is composed of a rationally designed UV light-responsive triangular DNA nano sucker (TDS) and upconversion nanoparticles (UCNPs), named UCNPs@TDS (UTDS), which can enter cells autonomously through endocytosis and enable remote regulation of on-demand accurate imaging for multiple intracellular miRNAs using NIR light illumination at a chosen time and place. It is worth noting that the most important highlight of the UTDS we designed in this work is that it can resist nonspecific activation as well as effectively avoid false-positive signals and improve the accuracy of imaging of multiple intracellular miRNAs. Moreover, distinguishing different kinds of cell lines with different miRNA expressions levels can be also achieved through this NIR light-activated intelligent UTDS, showing feasible prospects in precise imaging and disease diagnosis.


Assuntos
MicroRNAs , Nanopartículas , DNA , Raios Infravermelhos , Reprodutibilidade dos Testes
2.
Nanoscale ; 13(28): 12356-12369, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34254625

RESUMO

Previous studies have revealed that the liver is the main target organ of deposition for engineered nanoparticles. The hepatotoxicity of silver nanoparticles (AgNPs), the widely used antimicrobial nanoparticles, has been of great interest. However, little is known about the regulatory mechanism of the mitochondria in AgNP-induced hepatotoxicity. In the present study, we found that AgNPs, rather than silver ions, induced mitochondrial dynamics disorders, oxidative stress, and mitochondria-dependent hepatocyte apoptosis in mice. Using human hepatocellular carcinoma (HepG2) cells, we confirmed that the interaction between dynamin-related protein 1 (DRP1)-dependent mitochondrial fission and oxidative stress promoted mitochondrial damage and mitochondria-dependent apoptosis induced by AgNPs, as determined by the elimination of DRP1 or addition of N-acetylcysteine (NAC). Interestingly, the crosstalk between DRP1-dependent mitochondrial fission and oxidative stress also activated mitophagy and autophagy flux blocking. Phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1) gene silencing contributed to the aggravation of mitochondrial damage, oxidative stress, and apoptosis. These results revealed that the interplay between mitochondrial fission and oxidative stress induced mitophagy defects and triggered AgNP-induced mitochondria-dependent apoptosis in liver cells both in vivo and in vitro. Our findings provide a perspective for the mechanism of hepatotoxicity induced by exposure to metal NPs.


Assuntos
Nanopartículas Metálicas , Dinâmica Mitocondrial , Animais , Apoptose , Dinaminas/metabolismo , Hepatócitos/metabolismo , Nanopartículas Metálicas/toxicidade , Camundongos , Estresse Oxidativo , Prata/toxicidade
3.
Anal Chem ; 93(30): 10679-10687, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34288646

RESUMO

Herein, an electrochemiluminescence (ECL) microRNA biosensor based on anti-fouling magnetic beads (MBs) and two signal amplification strategies was developed. The newly designed anti-fouling dendritic peptide was wrapped on the surfaces of MBs to make them resistant to nonspecific adsorption of biomolecules in complex biological samples so as to realize accurate and selective target recognition. One of the amplification strategies was achieved through nucleic acid cycle amplification based on the DNAzyme on the surfaces of MBs. Then, the output DNA generated by the nucleic acid cycle amplification program stimulated the hybrid chain reaction (HCR) process on the modified electrode surface to generate the other amplification of the ECL response. Titanium dioxide nanoneedles (TiO2 NNs), as a co-reaction accelerator of the Ru(bpy)2(cpaphen)2+ and tripropylamine (TPrA) system, were wrapped with the electrodeposited polyaniline (PANI) on the electrode surface to enhance the ECL intensity of Ru(bpy)2(cpaphen)2+. The conducting polymer PANI can not only immobilize the TiO2 NNs but also improve the conductivity of the modified electrodes. The biosensor exhibited ultra-high sensitivity and excellent selectivity toward the detection of miRNA 21, with a detection limit of 0.13 fM. More importantly, with the anti-fouling MBs as a unique separation tool, this ECL biosensor was capable of assaying targets in complex biological media such as serum and cell lysate.


Assuntos
Incrustação Biológica , Técnicas Biossensoriais , MicroRNAs , Incrustação Biológica/prevenção & controle , Técnicas Eletroquímicas , Medições Luminescentes , Fenômenos Magnéticos
4.
Food Chem Toxicol ; 154: 112324, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34111491

RESUMO

As the release of silver nanoparticles (AgNPs) in the environment continues to increase, great concerns have been raised about their potential toxicity to humans. It is urgent to assess the possible toxicity of AgNPs to the immune cells of the central nervous system due to the continuous accumulation of AgNPs in the brain. This study aimed to evaluate the neurotoxicity of AgNPs and the regulatory mechanism of autophagy in AgNPs-induced inflammation by using mouse microglia BV2 cell lines. AgNPs decreased the microglia cell activity in a concentration and time-dependent manner. The exposure of BV2 cells to AgNPs at a non-cytotoxic level of 5 µg/mL resulted in increase of pro-inflammatory cytokines and decrease of mRNA expression of anti-inflammatory cytokines. AgNPs exposure increased M1 markers of iNOS expression and decreased the expression of M2 markers of CD206 in a time-dependent manner. Meanwhile, the expression of inflammatory proteins IL-1ß and NF-κB increased significantly. Additionally, AgNPs induced an increase in autophagosome and upregulation of LC3II, Beclin1, and p62 expression levels. Pretreatment by an autophagy inhibitor, 3-Methyladenine, caused more AgNPs-treated microglia to polarized into pro-inflammatory phenotypes. Inhibition of autophagy also increased the expression of inflammation-associated mRNA and proteins in BV2 cells. These results indicated that AgNPs could induce pro-inflammatory phenotypic polarization of microglia and the autophagy could play a key regulatory role in the pro-inflammatory phenotypic polarization of microglia induced by AgNPs.

5.
J Appl Toxicol ; 2021 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-33993517

RESUMO

Silver nanoparticles (AgNPs) have become widespread in the environment with increasing industrial applications. But the studies about their potential health risks are far from enough, especially in neurotoxic effects. This study aimed to investigate the neurotoxic effects of longer-term exposure (prolonged exposure for 48 h and chronic exposure for 6 days) of 20nm AgNPs with/without polyvinylpyrrolidone (PVP) coating at low concentrations (0.01-10 mg·L-1 ) to Caenorhabditis elegans. The results suggested that exposure to AgNPs induced damage to nematode survival, with the longest and relative average life span reduced. Exposure to AgNPs caused neurotoxicity on locomotion behaviors (head thrashes, body bends, pharyngeal pumping frequency, and defecation interval) and sensory perception behaviors (chemotaxis assay and thermotaxis assay), as well as impaired dopaminergic, GABAergic, and cholinergic neurons, except for glutamatergic, based on the alters fluorescence intensity, in a dose- and time-dependent manner. Further investigations suggested that the low-dose AgNPs (0.01-0.1 mg·L-1 ) exposure raises receptors of GABAergic and dopamine in C. elegans at the genetic level, whereas opposite results were observed at higher doses (1-10 mg·L-1 ), which implied that AgNPs could cause neurotoxicity by impairing neurotransmitter delivery. The PVP-AgNPs could cause a higher fatality rate and neurotoxicity at the same dose. Notably, AgNPs did not cause any deleterious effect on nematodes at the lowest dose of 0.01 mg·L-1 . In general, these results suggested that AgNPs possess the neurotoxic potential in C. elegans and provided useful information to understand the neurotoxicity of AgNPs, which would offer an inspiring perspective on the safe application.

6.
ACS Nano ; 15(4): 6961-6976, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33820415

RESUMO

The development of a theragnostic platform integrating precise diagnosis and effective treatment is significant but still extremely challenging. Herein, an integrated smart nanodevice composed of Au@Cu2-xS@polydopamine nanoparticles (ACSPs) and fuel DNA-conjugated tetrahedral DNA nanostructures (fTDNs) was constructed, in which the ACSP nanoprobe played multiple key roles in antitumor therapy as well as in situ monitoring of microRNAs (miRNAs) in cancer cells. Regarding the analysis, the ACSP probe contained two optical properties: excellent surface-enhanced Raman scattering (SERS) enhancement and high fluorescence (FL) quenching performance. Employing the ACSPs as the high-efficiency detection substrate combined with the fTDN-assisted DNA walking nanomachines as the superior amplification strategy, a SERS-FL dual-spectrum biosensor was constructed, which achieved an ultralow background signal and excellent sensitivity with detection limits of 0.11 pM and 4.95 aM by FL and SERS, respectively. Moreover, the rapid FL imaging and precise SERS quantitative detection for miRNA in cancer cells were also achieved by dual-signal ratio strategy, improving the accuracy of diagnosis. Regarding the therapeutic application, due to the high reactive oxygen species generation ability and excellent photothermal conversion efficiency, the ACSPs can also act as an all-in-one nanoagent for multimodal collaborative tumor therapy. Significantly, both in vivo and in vitro experiments confirmed its high biological safety and strong anticancer effect, indicating its promising theragnostic applications.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , MicroRNAs , Neoplasias , Animais , Aves , DNA , Ouro , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Análise Espectral Raman
7.
Ecotoxicol Environ Saf ; 208: 111696, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396027

RESUMO

With the widespread application and inevitable environmental exposure, silver nanoparticles (AgNPs) can be accumulated in various organs. More serious concerns are raised on the biological safety and potential toxicity of AgNPs in the central nervous system (CNS), especially in the hippocampus. This study aimed to investigate the biological effects and the role of PI3K/AKT/mTOR signaling pathway in AgNPs mediated cytotoxicity using the mouse hippocampal neuronal cell line (HT22 cells). AgNPs reduced cell viability and induced membrane leakage in a dose-dependent manner, determined by the MTT and LDH assay. In doses of 25, 50, 100 µg mL-1 for 24 h, AgNPs promoted the excessive production of reactive oxygen species (ROS) and caused the oxidative stress in HT22 cells. AgNPs induced autophagy, determined by the transmission electron microscopy observation, upregulation of LC3 II/I and downregulation of p62 expression levels. The mechanistic investigation showed that the PI3K/AKT/mTOR signaling pathway was activated by phosphorylation, which was enrolled in an AgNP-induced autophagy process. AgNPs could further trigger the apoptosis by upregulation of caspase-3 and Bax and downregulation of Bcl-2 in HT22 cells. These results revealed AgNP-induced cytotoxicity in HT22 cells, which was mediated by autophagy and apoptosis via the PI3K/AKT/mTOR signaling pathway. The study could provide the experimental evidence and explanation for the potential neurotoxicity triggered by AgNPs in vitro.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Transdução de Sinais/efeitos dos fármacos , Prata/toxicidade , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Serina-Treonina Quinases TOR/metabolismo
8.
Ecotoxicol Environ Saf ; 208: 111463, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33130480

RESUMO

With the increasing use of silver nanoparticles (AgNPs) in biological materials, the cytotoxicity caused by these particles has attracted much attention. However, the molecular mechanism underlying AgNP cytotoxicity remains unclear. In this study, we aimed to systematically investigate the toxicity induced by AgNP exposure to the lung adenocarcinoma A549 cell line at the subcellular and signaling pathway levels and elucidate the related molecular mechanism. The survival rate of cells exposed to AgNPs at 0, 20, 40, 80, and 160 µg/mL for 24 or 48 h decreased in a dose- and time-dependent manner. AgNPs induced autophagy and mitophagy, determined by the transmission electron microscopy investigation and upregulation of LC3 II/I, p62, PINK1, and Parkin expression levels. AgNP treatment induced lysosomal injury, including the decline of lysosomal membrane integrity and increase in cathepsin B level. The decreased in mitochondrial membrane potential, along with upregulation of cytochrome c, caspases 9 and 3, and BAX/BCL2, further suggested that mitochondrial injury were involved in AgNP-induced apoptosis. In addition, mitochondrial injury may further lead to excessive production of reactive oxygen species and oxidative/ antioxidant imbalance. The results suggested that AgNPs could regulate autophagy via mitochondrial and lysosome injury in A549 cells. The information of the molecular mechanism will provide an experimental basis for the safe application of nanomaterials.


Assuntos
Nanopartículas Metálicas/toxicidade , Mitofagia/fisiologia , Prata/toxicidade , Células A549 , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Caspase 9 , Morte Celular/efeitos dos fármacos , Humanos , Lisossomos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitofagia/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Ubiquitina-Proteína Ligases
9.
J Appl Toxicol ; 41(1): 65-81, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32686875

RESUMO

With the development of nanotechnology, metal-containing nanoparticles are used widely in the diagnosis, monitoring and treatment of central nervous system (CNS) diseases. The neurotoxicity of these nanoparticles has drawn attention. Glial cells (particularly microglial cells and astrocytes) have important functions in the CNS. Neural disorders are related to functional/histologic damage to glial cells. Dysfunctions of microglial cells or astrocytes injure the brain, and cause the neurodegeneration seen in Alzheimer's disease and Parkinson's disease. We have summarized the route of access of metal-containing nanoparticles to the CNS, as well as their neurotoxicity and potential molecular mechanisms involved in glial cells. Metal-containing nanoparticles cross or bypass the blood-brain barrier, access the CNS and cause neurotoxicity. The potential mechanisms are related to inflammation, oxidative stress, DNA and/or mitochondrial damage and cell death, all of which are mediated by microglial cell activation, inflammatory factor release, generation of reactive oxygen species, apoptosis and/or autophagy in glial cells. Moreover, these processes increase the burden of the CNS and even accelerate the occurrence or development of neurodegenerative diseases. Some important signaling pathways involved in the mechanism of neurotoxicity in glial cells caused by nanoparticles are also discussed.

10.
Anal Methods ; 12(48): 5916-5921, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33290456

RESUMO

A simple, accurate and reliable analytical method for simultaneous determination of chlorite, chlorate, perchlorate and bromate in ozonated saline by using ion chromatography coupled with triple quadrupole mass spectrometry (IC-MS) has been developed. The use of silver (Ag) and hydrogen (H) OnGuard cartridges and 100-fold dilution were found to be simple and effective for sample pretreatment. Under optimized MS parameters, method validation was convincingly confirmed. A good linearity was obtained with regression correlation coefficients (R2) larger than 0.999. The mean relative recoveries of chlorite (ClO2-), chlorate (ClO3-), perchlorate (ClO4-), and bromate (BrO3-) ranged from 79.96 to 97.63%. The obtained limit of detection (LOD) was 1.00 µg L-1 for ClO2-, 0.10 µg L-1 for ClO3-, 0.04 µg L-1 for ClO4-, and 0.50 µg L-1 for BrO3-. Chlorate and bromate were only detected in ozonated samples. In addition, the concentration of chlorate and bromate was in direct proportion to the amount of ozone in saline.

11.
Anal Chim Acta ; 1136: 134-140, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33081937

RESUMO

In this paper, an effective and accurate ratiometric electrochemiluminescence (ECL) system based on Au-luminol and CdS quantum dots (CdS QDs) as signal probes was constructed for detecting carcinoembryonic antigen (CEA). Polyaniline (PANI) and gold nanoparticles (AuNPs) strongly enhanced the electronic transfer efficiency and the specific area of the modified sensing surface, and improved the detection sensitivity. CdS QDs functionalized DNA strands functioned as cathode ECL emitters, and the aptamer of CEA modified with Au-luminol and quencher cyanine dye (Cy5) fluorophore functioned as anode ECL emitters. After the DNA capture probe combined with CEA aptamer, the negative potential ECL response of the CdS QDs was quenched because of electrochemiluminescence resonance energy transfer (ERET) between the Cy5 fluorophore and CdS QDs. However, the positive potential ECL response of Au-luminol can still be detected. The negative potential ECL response of CdS QDs was recovered, and the positive potential ECL response of Au-luminol decreased after CEA combined with its aptamer to take Cy5 and Au-luminol off the sensing interface. Additionally, the peptide provided effective anti-fouling performance in the detection of complex samples. The ratiometric ECL sensor with anti-fouling ability can sensitively determine the concentration of CEA in human serum.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Pontos Quânticos , Antígeno Carcinoembrionário , Técnicas Eletroquímicas , Ouro , Humanos , Limite de Detecção , Luminescência , Medições Luminescentes , Peptídeos
12.
Chem Commun (Camb) ; 56(39): 5271-5274, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32270827

RESUMO

We designed a dual-color fluorescent nanoprobe for simultaneous detection and imaging of adenosine triphosphate and glutathione in living cells based on porous carbon nanospheres and a DNA hybrid hydrogel. Due to the non-template synthesis process and good biocompatibility, the nanohydrogel displayed a short preparation time and anti-nonspecific adsorption.


Assuntos
Biomarcadores Tumorais/análise , Carbono/química , Reagentes para Ligações Cruzadas/química , DNA/química , Hidrogéis/química , Nanopartículas/química , Humanos , Células MCF-7 , Estrutura Molecular , Imagem Óptica , Tamanho da Partícula , Porosidade , Propriedades de Superfície
13.
Mikrochim Acta ; 187(4): 249, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32221723

RESUMO

The present study shows that a dual-signal nanoprobe consisting of DNAzyme-functionalized porous carbon nanospheres (PCNs) responds to microRNA-21 and zinc ion (Zn2+). The fluorescent probe undergoes an increase in the fluorescence intensity of fluorescein isothiocyanate (FITC) (with excitation/emission wavelengths at 488/517 nm) and the fluorescence intensity of cyanine-5 (Cy5) (with excitation/emission wavelengths at 633/670 nm) in the presence of microRNA-21 and Zn2+. The recognition between microRNA-21 and its complementary strand in the PCNs induces the separation of Zn2+-specific DNAzyme from PCNs, thus resulting in the increase of green fluorescence, and the exogenous Zn2+ triggers the rupture of cleavage strand of DNAzyme and recovery of red fluorescence. This nanoprobe allows us to acquire in vitro the determination of microRNA-21 in the range of 2-300 nM with a detection limit of 0.57 nM and the determination of Zn2+ in the range 2-100 nM with a detection limit of 0.43 nM, and in situ simultaneous imaging in MCF-7 breast cancer cells. Therefore, this strategy permits to obtain the expression levels of different biomarkers in living cells, providing a useful tool for diagnosis of cancers and understanding their biological process. Graphical abstract Schematic representation of the DNAzyme-functionalized porous carbon nanospheres for the imaging analysis of microRNA-21 and Zn2+ in living cells.

14.
J Appl Toxicol ; 40(6): 815-831, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31984544

RESUMO

This study evaluated the biodistribution and organ oxidative effects of silver nanoparticles (AgNPs) coated with/without polyvinylpyrrolidone (PVP) (AgNP-20 and AgNP-PVP) in mice; these were administered by gavage at a dose of 10-250 mg/kg body weight per day for 28 days. The results showed that both the AgNPs could induce subacute toxicity and oxidative damage to mice and were mainly accumulated in the liver and spleen and excreted by feces. AgNPs could be absorbed into blood and might cross the blood-brain barrier, and be distributed extensively in mice. The malondialdehyde content in the liver, lungs and kidneys increased in both AgNP groups, while the content of glutathione decreased, and the activity of superoxide dismutase increased at first and then decreased along with the increased doses. Inflammatory pathological changes in the lung and liver at high dose of both AgNPs were consistent with increases in glutamate pyruvic transaminase, glutamate oxaloacetic transaminase and the total protein in serum detection. The Ag content was detected in organs, with the highest content in the liver, followed by spleen, while the Ag content in feces was about 500 times higher than that in urine. AgNP-PVP could induce higher oxidative stress and subacute toxicity than AgNP-20 at the same dose, which might be related to the higher concentrations and more Ag+ ions released in mice after AgNP-PVP exposure. The data from this research provided information on toxicity and biodistribution of AgNPs following gavage administration in mice, and might shed light for future application of AgNPs in daily life.

15.
Anal Biochem ; 590: 113532, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31821806

RESUMO

A sensitive and selective fluorescence assay for DNA methyltransferase (MTase) activity detection was designed based on aggregation-induced emission (AIE) and target initiated template-free DNA polymerization. Quaternized tetraphenylethene salt was synthesized as the AIE probe, which binds to single-stranded DNA by electrostatic interaction. A hairpin probe was designed with a specific sequence for DNA MTase. In the presence of DNA MTase, the methylation reaction initiated DNA polymerization with terminal deoxynucleotidyl transferase (TdT), which activated the fluorescence intensity through AIE. The designed DNA sensor displayed a linear response to concentrations of DNA adenine methyltransferase (Dam) MTase from 0.5 U·mL-1 to 100 U mL-1, with a limit of detection of 0.16 U mL-1. The assay was also effective for detection of DNA MTase activity in human serum and for showing the inhibitory effect of 5-fluorouracil on Dam MTase.


Assuntos
Técnicas Biossensoriais/métodos , Metilases de Modificação do DNA/análise , Técnicas de Amplificação de Ácido Nucleico/métodos , DNA de Cadeia Simples/química , Escherichia coli/metabolismo , Fluorescência , Humanos
16.
Biosens Bioelectron ; 147: 111778, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655382

RESUMO

In this work, a new 3D DNA nanosphere was ingeniously designed and fabricated, which was used to combine with multiple enzyme-free amplification strategy to develop a photoelectrochemical (PEC) biosensing platform for ultrasensitive detection of carcinoembryonic antigen (CEA). The 3D DNA nanostructure was self-assembled by base complementary pairing in a few minutes and rolling circle amplification (RCA) reaction. The intense photocurrent derived from Au NPs/ZnSe QDs can be effectively decreased by 3D DNA nanospheres assembled on the electrode, making photoelectric signal present "off" state. The specific binding of target CEA with its hairpin (HP1) aptamer opens HP1 structure, which initiated multiple enzyme-free strand displacement amplification (SDA) reaction and generated a large number of single strands DNA S1. Then S1 competitively binds to capture DNA on the electrode to release 3D DNA nanospheres, thus the photocurrent signal became "on" state for achieving amplified assay of target CEA. The proposed PEC biosensor exhibits excellent performance with a wide linear range of 1.0 fg/mL to 10 ng/mL and a low detection limit of 0.12 fg/mL for CEA, which was successfully applied for the assay of real serum samples with good precision. The reported strategy opens a new simple way for PEC biosensor using DNA nanostructure, showing huge potential in clinical application research.


Assuntos
Biomarcadores Tumorais/isolamento & purificação , Técnicas Biossensoriais , Técnicas Eletroquímicas , Neoplasias/diagnóstico , Biomarcadores Tumorais/química , Biomarcadores Tumorais/genética , DNA de Cadeia Simples/química , Ouro/química , Humanos , Nanopartículas Metálicas/química , Nanosferas/química , Nanoestruturas/química , Neoplasias/genética , Pontos Quânticos/química
17.
Environ Pollut ; 256: 113430, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31685329

RESUMO

Silver nanoparticles (AgNPs) are inevitably released into the environment owing to their widespread applications in industry and medicine. The potential of their toxicity has aroused a great concern. Previous studies have shown that AgNPs exposure in HepG2 cells is primarily related to the damage of mitochondria, which includes induction of mitochondrial swelling and increase of intracellular levels of reactive oxygen species (ROS), the collapse of mitochondrial membrane potential and induction of apoptosis through a mitochondrial pathway. In this study, the effects of AgNPs exposure in HepG2 cells on mitochondrial dynamics and biogenesis were investigated. AgNPs were found to induce mitochondrial morphological and structural alterations. The expressions of key proteins (Drp1, Fis1, OPA1, Mff, Mfn1, and Mfn2) related to mitochondrial fission/fusion event were changed. Especially the expression of fission-related protein 1 (p-Drp1) (Ser616) was significantly up-regulated, whereas the expression of mitochondrial biogenesis protein (PGC-1α) was reduced in AgNP-treated cells. Concomitantly, the expression of autophagy marker proteins (LC3B and p62) was increased. The results suggested that AgNPs could trigger cytotoxicity by targeting the mitochondria, resulting in the disruption of mitochondrial function, damage to the mitochondrial structure and morphology, interfering in mitochondrial dynamics and biogenesis. The mitochondria could be a critical target of AgNPs in cells. The functions of mitochondria could be used for assessing the cytotoxic effects associated with AgNPs in cells.


Assuntos
Nanopartículas Metálicas/toxicidade , Mitocôndrias/efeitos dos fármacos , Prata/toxicidade , Animais , Apoptose , Substâncias Perigosas , Células Hep G2 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
18.
Analyst ; 145(1): 150-156, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31720590

RESUMO

The DNA tetrahedron has developed a broad spectrum of applications in biosensor construction thanks to its excellent mechanical rigidity and structural stability. However, how to construct a highly sensitive biosensor using a DNA tetrahedron is still a challenge. In this work, an ultrasensitive electrochemical biosensor based on a DNA tetrahedral nanostructure was developed with the help of synergy from proximity-dependent hybridization. To decrease the steric hindrance of DNA tetrahedra to proximity-dependent hybridization, the detection signal was set on the inclined side chain structure of a DNA tetrahedral sensing system. Additionally, when the target hybridized with the DNA probe, the ferrocene (Fc) labeled on the end of the DNA probe was driven close to the surface of the biosensor, providing a sensitive faradaic current. The experimental results exhibited a good linear relationship from 1 fM to 10 pM with a linear correlation coefficient of 0.9977, and a high sensitivity with a detection limit of 0.2 fM. Our DNA biosensor also showed good stability according to electrode characterization and target detection at different time scales and the anti-jamming capabilities in a complicated biological extraction environment were excellent. The electrochemical sensing system established here has greatly improved the detection sensitivity of a DNA biosensor based on a DNA tetrahedron, which will further promote its practical applications.


Assuntos
Técnicas Biossensoriais/métodos , Sondas de DNA/química , DNA/sangue , Técnicas Eletroquímicas/métodos , Animais , Bovinos , DNA/genética , Sondas de DNA/genética , Técnicas Eletroquímicas/instrumentação , Eletrodos , Compostos Ferrosos/química , Ouro/química , Limite de Detecção , Listeria monocytogenes/química , Metalocenos/química , Conformação Molecular , Nanoestruturas/química , Hibridização de Ácido Nucleico
19.
Chem Commun (Camb) ; 55(36): 5243-5246, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-30989156

RESUMO

Herein, we have designed a ratiometric fluorescent nanoprobe for adenosine triphosphate sensing and imaging in living cells, based on silica nanoparticles and a DNA-functionalized hybrid hydrogel. This ratiometric detecting method could validly avoid false-positive signals. Due to its controllable size, favorable biocompatibility and biostability, the nanohydrogel exhibited high cellular permeability and fast response in living cells.


Assuntos
Trifosfato de Adenosina/análise , DNA/química , Corantes Fluorescentes/química , Hidrogéis/química , Nanopartículas/química , Dióxido de Silício/química , Materiais Biocompatíveis/química , Linhagem Celular , Reagentes para Ligações Cruzadas/química , Transferência Ressonante de Energia de Fluorescência/métodos , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Imagem Óptica/métodos , Tamanho da Partícula , Processos Fotoquímicos , Polimerização , Propriedades de Superfície
20.
Anal Sci ; 35(3): 337-341, 2019 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-30449835

RESUMO

Meat screening plays a significant role in human health and religion. But the identification methods for beef were little reported. In this work, a simple colorimetric method based on denaturation bubble-mediated strand exchange amplification (SEA) was developed for the rapid and sensitive identification of beef. The whole strategy was performed on a portable metal bath and the distinguishable color between positive and negative controls was observed directly by the naked eyes. The feasibility using crude extraction samples by a heating treatment in PBS for 2 min was evaluated in duck spiked by beef. The result demonstrated that the developed method could identify as low as 1% (w/w) beef/duck within 50 min. Meanwhile, the results showed the method had a good repeatability and specificity. Therefore, this assay allows for the rapid, sensitive, specific detection of beef, and can be recommended as an effective, promising strategy for on-site meat identification.


Assuntos
Técnicas Biossensoriais/métodos , DNA/genética , Qualidade dos Alimentos , Técnicas de Amplificação de Ácido Nucleico/métodos , Carne Vermelha/análise , Animais , Bovinos , Desnaturação de Ácido Nucleico , Carne Vermelha/classificação , Carne Vermelha/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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