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1.
Mikrochim Acta ; 188(10): 316, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34476615

RESUMO

A novel label-free surface plasmon resonance (SPR) aptasensor has been constructed for the detection of N-gene of SARS-CoV-2 by using thiol-modified niobium carbide MXene quantum dots (Nb2C-SH QDs) as the bioplatform for anchoring N-gene-targeted aptamer. In the presence of SARS-CoV-2 N-gene, the immobilized aptamer strands changed their conformation to specifically bind with N-gene. It thus increased the contact area or enlarged the distance between aptamer and the SPR chip, resulting in a change of the SPR signal irradiated by the laser (He-Ne) with the wavelength (λ) of 633 nm. Nb2C QDs were derived from Nb2C MXene nanosheets via a solvothermal method, followed by functionalization with octadecanethiol through a self-assembling method. Subsequently, the gold chip for SPR measurements was modified with Nb2C-SH QDs via covalent binding of the Au-S bond also by self-assembling interaction. Nb2C-SH QDs not only resulted in high bioaffinity toward aptamer but also enhanced the SPR response. Thus, the Nb2C-SH QD-based SPR aptasensor had low limit of detection (LOD) of 4.9 pg mL-1 toward N-gene within the concentration range 0.05 to 100 ng mL-1. The sensor also showed excellent selectivity in the presence of various respiratory viruses and proteins in human serum and high stability. Moreover, the Nb2C-SH QD-based SPR aptasensor displayed a vast practical application for the qualitative analysis of N-gene from different samples, including seawater, seafood, and human serum. Thus, this work can provide a deep insight into the construction of the aptasensor for detecting SARS-CoV-2 in complex environments. A novel label-free surface plasmon resonance aptasensor has been constructed to detect sensitively and selectively the N-gene of SARS-CoV-2 by using thiol-modified niobium carbide MXene quantum dots as the scaffold to anchor the N-gene-targeted aptamer.


Assuntos
Aptâmeros de Nucleotídeos , COVID-19/diagnóstico , Nióbio/química , Nucleocapsídeo/metabolismo , Pontos Quânticos/química , SARS-CoV-2/isolamento & purificação , Ressonância de Plasmônio de Superfície/métodos , COVID-19/virologia , Humanos , Limite de Detecção
2.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360901

RESUMO

The oxidative properties of nanomaterials arouse legitimate concerns about oxidative damage in biological systems. On the other hand, the undisputable benefits of nanomaterials promote them for biomedical applications; thus, the strategies to reduce oxidative potential are urgently needed. We aimed at analysis of nitrogen-containing carbon quantum dots (N-CQDs) in terms of their biocompatibility and internalization by different cells. Surprisingly, N-CQD uptake does not contribute to the increased oxidative stress inside cells and lacks cytotoxic influence even at high concentrations, primarily through protein corona formation. We proved experimentally that the protein coating effectively limits the oxidative capacity of N-CQDs. Thus, N-CQDs served as an immobilization support for three different enzymes with the potential to be used as therapeutics. Various kinetic parameters of immobilized enzymes were analyzed. Regardless of the enzyme structure and type of reaction catalyzed, adsorption on the nanocarrier resulted in increased catalytic efficiency. The enzymatic-protein-to-nanomaterial ratio is the pivotal factor determining the course of kinetic parameter changes that can be tailored for enzyme application. We conclude that the above properties of N-CQDs make them an ideal support for enzymatic drugs required for multiple biomedical applications, including personalized medical therapies.


Assuntos
Biocatálise , Carbono/química , Carbono/farmacologia , Nitrogênio/química , Nitrogênio/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Coroa de Proteína/metabolismo , Pontos Quânticos/química , Pontos Quânticos/metabolismo , Células A549 , Animais , Apirase/química , Apirase/farmacologia , Catalase/química , Catalase/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Microambiente Celular/efeitos dos fármacos , Enzimas Imobilizadas/química , Enzimas Imobilizadas/farmacologia , Células HeLa , Humanos , Ratos , Espécies Reativas de Oxigênio/metabolismo , beta-Galactosidase/química , beta-Galactosidase/farmacologia
3.
Molecules ; 26(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443582

RESUMO

Biological imaging is an essential means of disease diagnosis. However, semiconductor quantum dots that are used in bioimaging applications comprise toxic metal elements that are nonbiodegradable, causing serious environmental problems. Herein, we developed a novel ecofriendly solvothermal method that uses ethanol as a solvent and doping with chlorine atoms to prepare highly fluorescent graphene quantum dots (GQDs) from seaweed. The GQDs doped with chlorine atoms exhibit high-intensity white fluorescence. Thus, their preliminary application in bioimaging has been confirmed. In addition, clear cell imaging could be performed at an excitation wavelength of 633 nm.


Assuntos
Cloro/química , Grafite/química , Imagem Molecular/métodos , Pontos Quânticos/química , Alga Marinha/química , Linhagem Celular , Fluorescência
4.
J Phys Chem Lett ; 12(33): 8080-8087, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34406017

RESUMO

Red-emitting carbon dots (C-dots) have tremendous potential for bioimaging and optoelectronic applications. Here, we investigated the structural modification of red-emitting C-dots due to boron doping and their ultrafast relaxation dynamics. It is evident from the X-ray photoelectron spectroscopy study that the relative percentage of pyrridinic nitrogen is increased at the expense of amino nitrogen and graphitic nitrogen in B-doped C-dots. Transient absorption spectroscopy and global target analysis reveal the formation of an additional excited-state level that takes away a significant amount of the excited-state population after boron doping. This new excited state slows the initial relaxation process toward the emissive state from 317 to 750 fs and increases the overall lifetime from 1.03 to 1.45 ns in B-doped C-dots.


Assuntos
Carbono/química , Pontos Quânticos/química , Boro/química , Análise Espectral/métodos
5.
ACS Appl Mater Interfaces ; 13(34): 40342-40353, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34412466

RESUMO

Sensitive point-of-care methods for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in clinical specimens are urgently needed to achieve rapid screening of viral infection. We developed a magnetic quantum dot-based dual-mode lateral flow immunoassay (LFIA) biosensor for the high-sensitivity simultaneous detection of SARS-CoV-2 spike (S) and nucleocapsid protein (NP) antigens, which is beneficial for improving the detection accuracy and efficiency of SARS-CoV-2 infection in the point-of-care testing area. A high-performance magnetic quantum dot with a triple-QD shell (MagTQD) nanotag was first fabricated and integrated into the LFIA system to provide superior fluorescence signals, enrichment ability, and detectability for S/NP antigen testing. Two detection modes were provided by the proposed MagTQD-LFIA. The direct mode was used for rapid screening or urgent detection of suspected samples within 10 min, and the enrichment mode was used for the highly sensitive and quantitative analysis of SARS-CoV-2 antigens in biological samples without the interference of the "hook effect." The simultaneous detection of SARS-CoV-2 S/NP antigens was conducted in one LFIA strip, and the detection limits for two antigens under direct and enrichment modes were 1 and 0.5 pg/mL, respectively. The MagTQD-LFIA showed high accuracy, specificity, and stability in saliva and nasal swab samples and is an efficient tool with flexibility to meet the testing requirements for SARS-CoV-2 antigens in various situations.


Assuntos
Antígenos Virais/análise , Técnicas Biossensoriais/métodos , Proteínas do Nucleocapsídeo de Coronavírus/análise , SARS-CoV-2/química , Glicoproteína da Espícula de Coronavírus/análise , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/imunologia , Antígenos Virais/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Fluorescência , Corantes Fluorescentes/química , Humanos , Imunoensaio/métodos , Limite de Detecção , Nanopartículas de Magnetita/química , Nasofaringe/virologia , Fosfoproteínas/análise , Fosfoproteínas/imunologia , Pontos Quânticos/química , Saliva/virologia , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia
6.
J Phys Chem Lett ; 12(32): 7671-7687, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34351771

RESUMO

Carbon dots (CDs) have excellent luminescence characteristics, such as good light stability, high quantum yield (QY), long phosphorescence lifetime, and a wide emission wavelength range, resulting in CDs' great success in optical applications. Understanding the structure-property relationships in CDs is essential for their use in optoelectronic applications. However, because of the complex nature of CD structures and synthesis processes, understanding the luminescence mechanism and structure-property relationships of CDs is a big challenge. This Perspective reviews the theoretical efforts toward the understanding of structure-property relationships and discusses the challenges that need to be overcome in future development of CDs.


Assuntos
Corantes Fluorescentes/química , Pontos Quânticos/química , Carbono/química , Teoria da Densidade Funcional , Fluorescência , Corantes Fluorescentes/síntese química , Aprendizado de Máquina , Modelos Químicos , Relação Estrutura-Atividade
7.
ACS Appl Mater Interfaces ; 13(33): 39030-39041, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34402305

RESUMO

Precise control over the assembly of biocompatible three-dimensional (3D) nanostructures would allow for programmed interactions within the cellular environment. Nucleic acids can be used as programmable crosslinkers to direct the assembly of quantum dots (QDs) and tuned to demonstrate different interparticle binding strategies. Morphologies of self-assembled QDs are evaluated via gel electrophoresis, transmission electron microscopy, small-angle X-ray scattering, and dissipative particle dynamics simulations, with all results being in good agreement. The controlled assembly of 3D QD organizations is demonstrated in cells via the colocalized emission of multiple assembled QDs, and their immunorecognition is assessed via enzyme-linked immunosorbent assays. RNA interference inducers are also embedded into the interparticle binding strategy to be released in human cells only upon QD assembly, which is demonstrated by specific gene silencing. The programmability and intracellular activity of QD assemblies offer a strategy for nucleic acids to imbue the structure and therapeutic function into the formation of complex networks of nanostructures, while the photoluminescent properties of the material allow for optical tracking in cells in vitro.


Assuntos
Reagentes para Ligações Cruzadas/química , Substâncias Luminescentes/química , Ácidos Nucleicos/química , Pontos Quânticos/química , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Sobrevivência Celular/efeitos dos fármacos , Rastreamento de Células , Portadores de Fármacos/química , Inativação Gênica/efeitos dos fármacos , Humanos , Modelos Moleculares , Imagem Óptica , Relação Estrutura-Atividade , Propriedades de Superfície
8.
Int J Mol Sci ; 22(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34299346

RESUMO

Research on carbon-based nanomaterials, such as carbon nanotubes, graphene and its derivatives, nanodiamonds, fullerenes, and other nanosized carbon allotropes, has experienced sharp exponential growth over recent years [...].


Assuntos
Nanoestruturas/química , Nanotubos de Carbono/química , Animais , Fulerenos/química , Grafite/química , Humanos , Nanodiamantes/química , Pontos Quânticos/química
9.
Int J Biol Macromol ; 185: 434-440, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34197848

RESUMO

This study investigated the interacting mechanism of CdTe quantum dots (QDs) with typical plasma protein transferrin (TF) as well as the impact of the formation of QDs-TF complex on the structure of TF and the cytotoxicity of mouse primary kidney cells. Dialysis experiments and cell viability assays revealed that the formation of QDs-TF complex reduced the contents of Cd released from CdTe QDs and thus counteracted the cytotoxicity of CdTe QDs. The assay of isothermal titration calorimetry found that CdTe QDs complexed with TF majorly through hydrophobic interaction. Multi-spectroscopic measurements showed that CdTe QDs caused the loosening of polypeptide chain, the changes of secondary and tertiary structures as well as the attenuated aggregation of TF molecule. Moreover, these structural and conformational changes were attributed to the nano-effects of CdTe QDs rather than the released Cd. This study is of great significance for fully evaluating the biocompatibility of Cd-QDs and comprehensively understanding the mechanism of Cd-QDs toxicity at the molecular and cellular level.


Assuntos
Compostos de Cádmio/toxicidade , Rim/citologia , Telúrio/toxicidade , Transferrina/química , Transferrina/metabolismo , Animais , Compostos de Cádmio/química , Calorimetria , Sobrevivência Celular/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Rim/efeitos dos fármacos , Masculino , Camundongos , Modelos Moleculares , Cultura Primária de Células , Estrutura Secundária de Proteína , Pontos Quânticos/química , Telúrio/química
10.
Comput Biol Chem ; 93: 107543, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34252797

RESUMO

Graphene quantum dot possesses advantageous characteristics like tunable fluorescence, nanometer size, low cytotoxicity, high biocompatibility enabling them as an ideal material for fluorescence bio-imaging. It exhibits a unique characteristic of DNA cleavage activity enhancer, gene/drug carrier, and anticancer targeting applications. In this article, we discussed the preparation of graphene quantum dot through the bottom-up method. Carbodiimide-activated amidation reactions were used for the functionalization of graphene quantum dot with Bovine Serum Albumin. Fluorescence spectroscopy data showed that the graphene quantum dot has size-dependent fluorescence emission. TEM and AFM studies showed that the size of graphene quantum dot was around 20 nm with narrow size distribution. Carbodiimide-activated amidation conjugation was successful in binding the protein onto graphene quantum dot and these conjugates were characterized by DLS, FTIR, fluorescence spectroscopy, and agarose gel electrophoresis. We also studied the structural-based in-silico molecular dynamic simulation by AutoDock, PyRx, and Discovery Studio Visualizer. Based on the virtual screening analysis and higher negative energy incorporation, it is observed that graphene quantum dot conjugated with bovine serum albumin quickly and formed is highly stable complex, which makes them a potential candidate for future applications in the field of bio-imaging, bio-sensing, gene/drug delivery, and tumor theragnostic.


Assuntos
Amidas/síntese química , Imidas/química , Simulação de Dinâmica Molecular , Imagem Óptica , Soroalbumina Bovina/química , Amidas/química , Animais , Bovinos , Fluorescência , Grafite/química , Pontos Quânticos/química
11.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204217

RESUMO

In this paper, the study of surface modification of two-dimensional (2D), non-luminescent CdS nanoplates (NPLs) by thiol-containing ligands is presented. We show that a process of twophase transfers with appropriate ligand exchange transforms non-luminescent NPLs into spherical CdS nanoparticles (NPs) exhibiting a blue photoluminescence with exceptionally high quantum yield ~90%. In the process, transfer from inorganic solvent to water is performed, with appropriately selected ligand molecules and pH values (forward phase transfer), which produces NPs with modified size and shape. Then, in reverse phase transfer, NPs are transferred back to toluene due to surface modification by combined Cd (OL)2 and Cd (Ac)2. As a result, spherical NPs are formed (average diameter between 4 and 6 nm) with PL QY as high as 90%. This is unique for core only CdS NPs without inorganic shell.


Assuntos
Compostos de Cádmio/química , Nanopartículas/química , Pontos Quânticos/química , Sulfetos/química , Fenômenos Químicos , Técnicas de Química Sintética , Nanopartículas/ultraestrutura , Transição de Fase , Análise Espectral
12.
ACS Appl Mater Interfaces ; 13(24): 27836-27844, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34105944

RESUMO

The use of nanogels (NGs) to modulate surface-enhanced Raman scattering (SERS) activities is introduced as an innovative strategy to address certain critical issues with SERS-based immunoassays. This includes the chemical deformation of SERS nanotags, as well as their nonspecific interactions and effective "hotspots" formation. Herein, the polymeric cocoon and stimuli-responsive properties of NGs were used to encapsulate SERS nanotags containing plasmonic molybdenum trioxide quantum dots (MoO3-QDs). The pH-controlled release of the encapsulated nanotags and their subsequent localization by maleimide-functionalized magnetic nanoparticles facilitated the creation of "hotspots" regions with catalyzed SERS activities. This approach resulted in developing a biosensing platform for the ultrasensitive immunoassays of hepatitis E virus (HEV) or norovirus (NoV). The immunoassays were optimized using the corresponding virus-like particles to attain limits of detection of 6.5 and 8.2 fg/mL for HEV-LPs and NoV-LPs, respectively. The SERS-based technique achieved a signal enhancement factor of up to ∼108 due to the combined electromagnetic and chemical mechanisms of the employed dual-SERS substrate of MoO3-QDs/2D hexagonal boron nitride nanosheets. The highlight and validation of the developed SERS-based immunoassays was the detection of NoV in infected patients' fecal specimen and clinical HEV G7 subtype. Importantly, this system can be used to maintain the stability of SERS nanotags and improve their reliability in immunoassays.


Assuntos
Vírus da Hepatite E/isolamento & purificação , Molibdênio/química , Nanogéis/química , Norovirus/isolamento & purificação , Óxidos/química , Pontos Quânticos/química , Anticorpos Imobilizados/imunologia , Técnicas Biossensoriais/métodos , Vírus da Hepatite E/imunologia , Humanos , Concentração de Íons de Hidrogênio , Imunoensaio , Limite de Detecção , Fenômenos Magnéticos , Nanopartículas/química , Norovirus/imunologia , Reprodutibilidade dos Testes , Análise Espectral Raman
13.
ACS Appl Mater Interfaces ; 13(24): 27983-27990, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34110765

RESUMO

Nanowire-based optical biosensors with high sensitivity are highly desired for the detection of biological microenvironments and analysis of cellular processes. However, the current nanowire biosensors are mostly fabricated with metal and semiconductor materials, which are not suitable for long-term use in biological environments due to their incompatible and nondegradable properties. Biosensors based on biofriendly materials (e.g., spider silk) often do not have high enough sensitivity due to high losses or micron sizes. Here, polylactic acid (PLA), a polymer with high optical transparency, good biocompatibility, biodegradability, and flexibility, is used to fabricate nanowires using a directly drawing method for the first time. Because of the strong evanescent wave and abundant carboxyl groups on the surface of nanowires, an ultralow concentration sensing of cytochrome c is achieved with a limit of detection of 1.38 × 10-17 M, which is much lower than other detection results using semiconductor/metal-based nanosensors (10-6 to 10-12 M). On this basis, a label-free and real-time monitoring of cell apoptosis is realized. In addition, by doping quantum dots, the functionalized PLA nanowires can also sense a change in pH. These results are suggestive of the potential for PLA nanowires applied in multifunctional biosensing and biodetection, pushing forward the photomedicine field.


Assuntos
Apoptose/fisiologia , Técnicas Biossensoriais/métodos , Citocromos c/análise , Nanofios/química , Poliésteres/química , Citocromos c/metabolismo , Concentração de Íons de Hidrogênio , Limite de Detecção , Pontos Quânticos/química , Leveduras/metabolismo
14.
ACS Appl Mater Interfaces ; 13(24): 27784-27795, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34126740

RESUMO

Graphene quantum dots (GQDs) are emerging as a versatile nanomaterial with numerous proposed biomedical applications. Despite the explosion in potential applications, the molecular interactions between GQDs and complex biomolecular systems, including potassium-ion (K+) channels, remain largely unknown. Here, we use molecular dynamics (MD) simulations and electrophysiology to study the interactions between GQDs and three representative K+ channels, which participate in a variety of physiological processes and are closely related to many disease states. Using MD simulations, we observed that GQDs adopt distinct contact poses with each of the three structurally distinct K+ channels. Our electrophysiological characterization of the effects of GQDs on channel currents revealed that GQDs interact with the extracellular voltage-sensing domain (VSD) of a Kv1.2 channel, augmenting current by left-shifting the voltage dependence of channel activation. In contrast, GQDs form a "lid" cluster over the extracellular mouth of inward rectifier Kir3.2, blocking the channel pore and decreasing the current in a concentration-dependent manner. Meanwhile, GQDs accumulate on the extracellular "cap domain" of K2P2 channels and have no apparent impact on the K+ flux through the channel. These results reveal a surprising multifaceted regulation of K+ channels by GQDs, which might help de novo design of nanomaterial-based channel probe openers/inhibitors that can be used to further discern channel function.


Assuntos
Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Grafite/metabolismo , Canal de Potássio Kv1.2/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Pontos Quânticos/metabolismo , Animais , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/química , Grafite/química , Células HEK293 , Humanos , Canal de Potássio Kv1.2/química , Camundongos , Simulação de Dinâmica Molecular , Canais de Potássio de Domínios Poros em Tandem/química , Ligação Proteica , Domínios Proteicos , Pontos Quânticos/química , Ratos
15.
ACS Appl Mater Interfaces ; 13(25): 29392-29405, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34137577

RESUMO

Chemiluminescence immunoassays have been widely employed for diagnosing various diseases. However, because of the extremely low intensity chemiluminescence signals, highly sensitive transducers, such as photomultiplier tubes and image sensors with cooling devices, are required to overcome this drawback. In this study, a hypersensitive photosensor was developed based on cesium lead bromide (CsPbBr3) perovskite quantum dots (QDs) with sufficient high sensitivity for chemiluminescence immunoassays. First, CsPbBr3 QDs with a highly uniform size, that is, 5 nm, were synthesized under thermodynamic control to achieve a high size confinement effect. For the fabrication of the photosensor, MoS2 nanoflakes were used as an electron transfer layer and heat-treated at an optimum temperature. Additionally, a parylene-C film was used as a passivation layer to improve the physical stability and sensitivity of the photosensor. In particular, the trap states on the CsPbBr3 QDs were reduced by the passivation layer, and the sensitivity was increased. Finally, a photosensor based on CsPbBr3 QDs was employed in chemiluminescence immunoassays for the detection of human hepatitis B surface antigen, human immunodeficiency virus antibody, and alpha-fetoprotein (AFP, a cancer biomarker). When compared with the conventionally used equipment, the photosensor was determined to be feasible for application in chemiluminescence immunoassays.


Assuntos
Compostos de Cálcio/química , Imunoensaio/métodos , Chumbo/química , Medições Luminescentes/métodos , Óxidos/química , Pontos Quânticos/química , Titânio/química , Césio/química , Anticorpos Anti-HIV/análise , Antígenos de Superfície da Hepatite B/análise , Humanos , Polímeros/química , Xilenos/química
16.
ACS Appl Mater Interfaces ; 13(25): 29340-29348, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34137582

RESUMO

We demonstrate a versatile nanoparticle with imaging-guided chemo-photothermal synergistic therapy and EpCAM-targeted delivery of liver tumor cells. EpCAM antibody (anti-EpCAM) and Pt(IV) were grafted onto the polydopamine carbon dots (PDA-CDs) by the amidation reaction. The EpCAM antibody of particles enables the targeted interaction with liver progenitor cells due to their overexpressed EpCAM protein. The tetravalent platinum prodrug [Pt(IV)] induces apoptosis with minimum toxic side effects through the interaction between cisplatin and tumor cell DNA. The nanoparticles displayed stable photothermal property and considerable anti-tumor therapeutic effect in vivo. Coupling with cellular imaging due to their fluorescence property, anti-EpCAM@PDA-CDs@Pt(IV) offers a convenient and effective platform for imaging-guided chemo-photothermal synergistic therapy toward liver cancers in the near future.


Assuntos
Antineoplásicos , Molécula de Adesão da Célula Epitelial/metabolismo , Corantes Fluorescentes , Indóis , Polímeros , Pontos Quânticos , Animais , Anticorpos Imobilizados/química , Anticorpos Imobilizados/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Feminino , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacocinética , Corantes Fluorescentes/farmacologia , Células HeLa , Células Hep G2 , Humanos , Indóis/química , Indóis/farmacocinética , Neoplasias Hepáticas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Polímeros/química , Polímeros/farmacocinética , Pontos Quânticos/química , Pontos Quânticos/metabolismo , Nanomedicina Teranóstica/métodos
17.
ACS Appl Mater Interfaces ; 13(25): 29936-29948, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34143617

RESUMO

Alzheimer's disease (AD) is a major cause of dementia characterized by the overexpression of transmembrane amyloid precursor protein and its neurotoxic byproduct amyloid beta (Aß). A small peptide of considerable hydrophobicity, Aß is aggregation prone catalyzed by the presence of cell membranes, among other environmental factors. Accordingly, current AD mitigation strategies often aim at breaking down the Aß-membrane communication, yet no data is available concerning the cohesive interplay of the three key entities of the cell membrane, Aß, and its inhibitor. Using a lipophilic Laurdan dye and confocal fluorescence microscopy, we observed cell membrane perturbation and actin reorganization induced by Aß oligomers but not by Aß monomers or amyloid fibrils. We further revealed recovery of membrane fluidity by ultrasmall MoS2 quantum dots, also shown in this study as a potent inhibitor of Aß amyloid aggregation. Using discrete molecular dynamics simulations, we uncovered the binding of MoS2 and Aß monomers as mediated by hydrophilic interactions between the quantum dots and the peptide N-terminus. In contrast, Aß oligomers and fibrils were surface-coated by the ultrasmall quantum dots in distinct testudo-like, reverse protein-corona formations to prevent their further association with the cell membrane and adverse effects downstream. This study offers a crucial new insight and a viable strategy for regulating the amyloid aggregation and membrane-axis of AD pathology with multifunctional nanomedicine.


Assuntos
Peptídeos beta-Amiloides , Dissulfetos/química , Fluidez de Membrana/fisiologia , Molibdênio/química , Pontos Quânticos/química , 2-Naftilamina/análogos & derivados , 2-Naftilamina/química , Actinas/química , Actinas/metabolismo , Doença de Alzheimer , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Linhagem Celular Tumoral , Membrana Celular/química , Membrana Celular/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lauratos/química , Microscopia Confocal , Simulação de Dinâmica Molecular , Nanomedicina
18.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070594

RESUMO

It is important to understand the nanomaterials intracellular trafficking and distribution and investigate their targeting into the nuclear area in the living cells. In our previous study, we firstly observed penetration of nonmodified positively charged carbon dots decorated with quaternary ammonium groups (QCDs) into the nucleus of mouse NIH/3T3 fibroblasts. Thus, in this work, we focused on deeper study of QCDs distribution inside two healthy mouse NIH/3T3 and L929 cell lines by fluorescence microspectroscopy and performed a comprehensive cytotoxic and DNA damage measurements. Real-time penetration of QCDs across the plasma cell membrane was recorded, concentration dependent uptake was determined and endocytic pathways were characterized. We found out that the QCDs concentration of 200 µg/mL is close to saturation and subsequently, NIH/3T3 had a different cell cycle profile, however, no significant changes in viability (not even in the case with QCDs in the nuclei) and DNA damage. In the case of L929, the presence of QCDs in the nucleus evoked a cellular death. Intranuclear environment of NIH/3T3 cells affected fluorescent properties of QCDs and evoked fluorescence blue shifts. Studying the intracellular interactions with CDs is essential for development of future applications such as DNA sensing, because CDs as DNA probes have not yet been developed.


Assuntos
Carbono , Ciclo Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Fibroblastos/metabolismo , Pontos Quânticos , Animais , Carbono/química , Carbono/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Microscopia de Fluorescência , Células NIH 3T3 , Pontos Quânticos/química , Pontos Quânticos/uso terapêutico
19.
Chem Commun (Camb) ; 57(51): 6288-6291, 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34075954

RESUMO

The dual-mode bio-imaging nanoprobe TP-CQDs@MnO2, based on two-photon carbon quantum dots and MnO2, has been developed for the two-photon fluorescence and MR imaging of endogenous H2O2 in the tumor microenvironment, and it achieved high selectivity, a great signal-to-noise ratio, a limit of detection (LOD) of 1.425 pM for H2O2, and a two-photon tissue penetration depth of 280 µm.


Assuntos
Peróxido de Hidrogênio/metabolismo , Imageamento por Ressonância Magnética , Microscopia Confocal , Nanoestruturas/química , Carbono/química , Linhagem Celular , Meios de Contraste/química , Humanos , Peróxido de Hidrogênio/análise , Limite de Detecção , Compostos de Manganês/química , Óxidos/química , Pontos Quânticos/química , Razão Sinal-Ruído , Espectrometria de Fluorescência , Microambiente Tumoral
20.
Chem Commun (Camb) ; 57(52): 6376-6379, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34081069

RESUMO

We demonstrate the zirconium ion-mediated assembly of a single quantum dot (QD)-based nanosensor for accurate detection of protein kinases (PKA) and polynucleotide kinases (PNK). This nanosensor is very sensitive with a detection limit of 8.82 × 10-4 U mL-1 for PKA and 1.40 × 10-5 U mL-1 for PNK. Moreover, it can be used to analyze the enzyme kinetic parameters and screen the inhibitors of PKA and PNK, with potential applications in drug discovery and clinical diagnosis.


Assuntos
Técnicas Biossensoriais/métodos , Polinucleotídeo 5'-Hidroxiquinase/análise , Proteínas Quinases/análise , Pontos Quânticos/química , Zircônio/química , Carbocianinas/química , Transferência Ressonante de Energia de Fluorescência , Células HeLa , Humanos , Limite de Detecção , Polinucleotídeo 5'-Hidroxiquinase/antagonistas & inibidores , Polinucleotídeo 5'-Hidroxiquinase/metabolismo , Proteínas Quinases/química , Proteínas Quinases/metabolismo
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