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1.
Brain Topogr ; 36(3): 283-293, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36856917

RESUMO

To explore alterations of resting-state functional connectivity (rsFC) in sensorimotor cortex following strokes with left or right hemiplegia considering the lateralization and neuroplasticity. Seventy-three resting-state functional near-infrared spectroscopy (fNIRS) files were selected, including 26 from left hemiplegia (LH), 21 from right hemiplegia (RH) and 26 from normal controls (NC) group. Whole-brain analyses matching the Pearson correlation were used for rsFC calculations. For right-handed normal controls, rsFC of motor components (M1 and M2) in the left hemisphere displayed a prominent intensity in comparison with the right hemisphere (p < 0.05), while for stroke groups, this asymmetry has disappeared. Additionally, RH rather than LH showed stronger rsFC between left S1 and left M1 in contrast to normal controls (p < 0.05), which correlated inversely with motor function (r = - 0.53, p < 0.05). Regarding M1, rsFC within ipsi-lesioned M1 has a negative correlation with motor function of the affected limb (r = - 0.60 for the RH group and - 0.43 for the LH group, p < 0.05). The rsFC within contra-lesioned M1 that innervates the normal side was weakened compared with that of normal controls (p < 0.05). Stronger rsFC of motor components in left hemisphere was confirmed by rs-fNIRS as the "secret of dominance" for the first time, while post-stroke hemiplegia broke this cortical asymmetry. Meanwhile, a statistically strengthened rsFC between left S1 and M1 only in right-hemiplegia group may act as a compensation for the impairment of the dominant side. This research has implications for brain-computer interfaces synchronizing sensory feedback with motor performance and transcranial magnetic regulation for cortical excitability to induce cortical plasticity.


Assuntos
Córtex Sensório-Motor , Acidente Vascular Cerebral , Humanos , Lateralidade Funcional/fisiologia , Hemiplegia/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Córtex Sensório-Motor/diagnóstico por imagem , Plasticidade Neuronal/fisiologia
2.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 52(1): 1-12, 2023 Feb 25.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-37283113

RESUMO

OBJECTIVES: To explore the effect of exposure to di (2-ethyl) hexyl phthalate (DEHP) in early pregnancy on endometrial decidualization in mice and its relation with lncRNA RP24-315D19.10. METHODS: Early pregnancy mice were exposed to DEHP (1000 mg·kg-1·d-1) to construct the model. The uterus was collected on day 6 of pregnancy to detect its effect on decidualization by HE staining and immunofluorescence. A decidualization induction model of mouse endometrial stromal cells exposed to DEHP (0.1, 0.5, 2.5, 12.5, 62.5 µmol/L) was constructed. The changes of cell morphology were observed by light microscopy and phalloidin staining, and the expression of decidual reaction related molecular markers were detected by immunofluorescence, realtime RT-PCR and Western blotting. The expression of RP24-315D19.10 in decidua tissue and cells was detected by realtime RT-PCR. Cellular localization of RP24-315D19.10 was determined by lncLocator database and RNA FISH. AnnoLnc2 database was used to predict miRNAs bound to RP24-315D19.10. RESULTS: The number of embryo implantation sites, uterine weight and uterine area were significantly lower in the DEHP exposed group than those in the control group, and the expression of the decidual reaction related molecular markers matrix metalloprotein 9 and homeobox A10 in the DEHP exposure group were also significantly lower than those in the control group (all P<0.05). With the increase of DEHP concentration, the expression of dtprp in decidua cells was gradually decreased. 2.5 µmol/L DEHP exposed stromal cells failed to be fully decidualized in vitro, andphalloidin staining showed abnormal cytoskeleton morphology. The expression levels of homeobox A10, bone morphogenetic protein 2 and proliferating cell nuclear antigen in the DEHP exposure group were significantly lower than those in the control group (all P<0.05). The expression of RP24-315D19.10 in DEHP exposed decidua tissue and cells was significantly reduced (both P<0.05). RP24-315D19.10 is mainly localized in the cytoplasm and RP24-315D19.10 might bind to 45 miRNAs, among them, miR-138-5p, miR-155-5p, miR-183-5p and miR-223-3p were associated with endometrial decidualization. CONCLUSIONS: DEHP exposure in early pregnancy may impair endometrial decidualization, and the damage may be associated with the down-regulation of RP24-315D19.10.


Assuntos
Dietilexilftalato , MicroRNAs , RNA Longo não Codificante , Gravidez , Feminino , Camundongos , Animais , Decídua/metabolismo , RNA Longo não Codificante/metabolismo , Dietilexilftalato/toxicidade , Dietilexilftalato/metabolismo , Plastificantes/toxicidade , Plastificantes/metabolismo , Proteínas Homeobox A10/metabolismo , Endométrio , MicroRNAs/metabolismo , Células Estromais/metabolismo
3.
J Am Chem Soc ; 143(39): 16256-16263, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34550674

RESUMO

Ultralong organic phosphorescence (UOP) has aroused enormous interest in recent years. UOP materials are mainly limited to crystals or rigid host-guest systems. Their poor processability and mechanical properties critically hamper practical applications. Here, we reported a series of ultralong phosphorescent foams with high mechanical strength. Phosphorescence lifetime of the foam can reach up to 485.8 ms at room temperature. Impressively, lightweight gelatin foam can bear a compressive pressure of 4.44 MPa. Moreover, phosphorescence emission of polymer foam can be tuned from blue to orange through varying the excitation wavelength. Experimental data and theoretical calculations revealed that ultralong phosphorescence was ascribed to the fixation of multiple hydrogen bonds to the clusters of carbonyl groups. These results will allow for expanding the scope of luminescent foams, providing an ideal platform for developing ultralong phosphorescent materials with high mechanical strength.

4.
Small ; 15(8): e1805022, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30698915

RESUMO

Layered stacking and highly porous N, P co-doped Mo2 C/C nanosheets are prepared from a stable Mo-enhanced hydrogel. The hydrogel is formed through the ultrafast cross-linking of phosphomolybdic acid and chitosan. During the reduction of the composite hydrogel framework under inert gas protection, highly porous N and P co-doped carbon nanosheets are produced with the in situ formation of ultrafine Mo2 C nanoparticles highly distributed throughout the nanosheets which are entangled via a hierarchical lamellar infrastructure. This unique architecture of the N, P co-doped Mo2 C/C nanosheets tremendously promote the electrochemical activity and operate stability with high specific capacity and extremely stable cycling. In particular, this versatile synthetic strategy can also be extended to other polyoxometalate (such as phosphotungstic acid) to provide greater opportunities for the controlled fabrication of novel hierarchical nanostructures for next-generation high performance energy storage applications.

5.
Angew Chem Int Ed Engl ; 57(48): 15772-15776, 2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30315618

RESUMO

Peristaltic crawling, which is the moving mechanism of earthworm-like limbless creatures in narrow spaces, is a challenging target to mimic by using soft materials. Here we report an unprecedented hydrogel actuator that enables not only a peristaltic crawling motion but also reversing its direction. Our cylindrically processed hydrogel contains gold nanoparticles for photothermal conversion, a thermoresponsive polymer network for switching the electrical permittivity of the gel interior, and cofacially oriented 2D electrolytes (titanate nanosheets; TiNSs) to synchronously change their anisotropic electrostatic repulsion. When a hydrogel, which was designed to include cofacially oriented TiNSs along the cylindrical gel axis, is pointwisely photoirradiated with a visible-light laser, it spatiotemporally expands immediately (<0.5 s) and largely (80 % of its original length) in an isovolumetric manner. When the irradiation spot is moved along the cylindrical gel axis, the hydrogel undergoes peristaltic crawling due to quick and sequential elongation/contraction events and moves oppositely toward the laser scanning direction. Thus, when the scanning direction is switched, the crawling direction is reversed. When gold nanorods are used in place of gold nanoparticles, the hydrogel becomes responsive to a near-infrared light, which can deeply penetrate into bio tissues.

6.
Angew Chem Int Ed Engl ; 54(27): 7944-8, 2015 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-26012538

RESUMO

A new type of multistimuli-responsive hydrogels cross-linked by metal ions and biopolymers is reported. By mixing the biopolymer chitosan (CS) with a variety of metal ions at the appropriate pH values, we obtained a series of transparent and stable hydrogels within a few seconds through supramolecular complexation. In particular, the CS-Ag hydrogel was chosen as the model and the gelation mechanism was revealed by various measurements. It was found that the facile association of Ag(+) ions with amino and hydroxy groups in CS chains promoted rapid gel-network formation. Interestingly, the CS-Ag hydrogel exhibits sharp phase transitions in response to multiple external stimuli, including pH value, chemical redox reactions, cations, anions, and neutral species. Furthermore, this soft matter showed a remarkable moldability to form shape-persistent, free-standing objects by a fast in situ gelation procedure.


Assuntos
Quitosana/química , Complexos de Coordenação/química , Hidrogéis/química , Transição de Fase , Prata/química , Concentração de Íons de Hidrogênio , Íons/química , Oxirredução
7.
Tumour Biol ; 35(1): 695-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23949881

RESUMO

Mothers against decapentaplegic homolog 7 (SMAD7) rs12953717 polymorphism has been implicated to alter the risk of colorectal cancer (CRC), but the results are controversial. The objective of this study was to quantitatively evaluate the association between SMAD7 rs12953717 polymorphism and CRC susceptibility. A comprehensive search was conducted to identify all eligible studies of SMAD7 rs12953717 polymorphism and CRC risk. Pooled odds ratio and 95% confidence interval were calculated using a fixed or random effects model. Statistical analysis was performed with Review Manager 5.0 and Stata 11. A total of 11 case-control studies, including 12,058 cases and 11,444 controls, were identified. The combined results based on all studies suggested that rs12953717 was associated with CRC risk under all genetic models. When stratifying for race, the data showed that the rs12953717 was associated with a significantly increased CRC risk under all genetic models in Caucasians. Statistically significant association was found in all genetic models except in recessive model comparison in the subgroup of Asians. After stratifying the studies by study design, there was a significant association between rs12953717 polymorphism and CRC risk under all genetic models in the subgroup of population-based studies. Our study suggests that rs12953717 polymorphism is associated with an increased CRC risk.


Assuntos
Neoplasias Colorretais/genética , Polimorfismo de Nucleotídeo Único , Proteína Smad7/genética , Alelos , Estudos de Casos e Controles , Neoplasias Colorretais/etnologia , Predisposição Genética para Doença , Genótipo , Humanos , Razão de Chances , Viés de Publicação , Risco
8.
Chemphyschem ; 15(12): 2421-30, 2014 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-24953044

RESUMO

This manuscript presents a brief overview of recent advances in multistimuli-responsive supramolecular gels (MRSGs). The synthesis of MRSGs with faster and smarter responsive abilities to a variety of external stimuli, such as redox reagents, pH changes, ligands, and coupling reagents, is one key issue for the upgrade of current molecular motors, signal sensors, shape memory devices, drug delivery systems, display devices, and other devices. However, the design rules of MRSGs are still not well understood. The lack of information about the relationship between the spatial structure and gelation behavior of existing gelators means that the knowledge required to design new gelators by the addition of functional moieties to well-known gelators is lacking. Insights into the gelation pathway of known gelators may bring inspiration to researchers who want to exploit elegant designs and specific building blocks to obtain their own MRSGs with predictable stimuli-responsive abilities.

9.
Int J Biol Macromol ; 273(Pt 2): 132957, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38848837

RESUMO

Food waste resulting from perishable fruits and vegetables, coupled with the utilization of non-renewable petroleum-based packaging materials, presents pressing challenges demanding resolution. This study addresses these critical issues through the innovative development of a biodegradable functional plastic wrap. Specifically, the proposed solution involves the creation of a κ-carrageenan/carboxymethyl chitosan/arbutin/kaolin clay composite film. This film, capable of rapid in-situ formation on the surfaces of perishable fruits, adeptly conforms to their distinct shapes. The incorporation of kaolin clay in the composite film plays a pivotal role in mitigating water vapor and oxygen permeability, concurrently bolstering water resistance. Accordingly, tensile strength of the composite film experiences a remarkable enhancement, escalating from 20.60 MPa to 34.71 MPa with the incorporation of kaolin clay. The composite film proves its efficacy by preserving cherry tomatoes for an extended period of 9 days at 28 °C through the deliberate delay of fruit ripening, respiration, dehydration and microbial invasion. Crucially, the economic viability of the raw materials utilized in the film, coupled with the expeditious and straightforward preparation method, underscores the practicality of this innovative approach. This study thus introduces an easy and sustainable method for preserving perishable fruits, offering a cost-effective and efficient alternative to petroleum-based packaging materials.


Assuntos
Carragenina , Quitosana , Argila , Embalagem de Alimentos , Hidrogéis , Caulim , Solanum lycopersicum , Quitosana/química , Quitosana/análogos & derivados , Caulim/química , Carragenina/química , Argila/química , Embalagem de Alimentos/métodos , Hidrogéis/química , Resistência à Tração , Conservação de Alimentos/métodos , Frutas/química , Permeabilidade
10.
J Am Chem Soc ; 135(36): 13379-86, 2013 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-23984683

RESUMO

In this paper we present a new paradigm for designing hydrogelators that exhibit sharp phase transitions in response to a series of disparate stimuli, including oxidation-reduction reactions (redox), guest-host interactions, and pH changes. We have serendipitously discovered that ferrocenoyl phenylalanine (Fc-F) monomers aggregate in water via a rapid self-assembly mechanism to form stable, multistimuli hydrogels. In comparison to other known mono- and multiresponsive gelators, Fc-F is unique because of its small size, economy of gel-forming components, and exceptionally simple molecular structure. Density functional theory (DFT) ab initio calculations suggest gel formation initially involves an antiparallel, noncovalent dimerization step wherein the ferrocenoyl moiety of one axe-like monomer conjoins with the phenyl group of the second monomer via a π-π stacking interaction to form brick-like dimers. This stacking creates a cavity in which the carboxylic acid groups of each monomer mutually interact via hydrogen bond formation, which affords additional stability to the dimer. On the basis of structural analysis via optical and electrical measurements and additional DFT calculations, we propose a possible stepwise hierachical assembly mechanism for fibril formation. Insights into the self-assembly pathway of Fc-F should prove useful for understanding gelation processes of more complex systems. We expect that Fc-F will serve as a helpful archetypical template for others to use when designing new, stimuli specific hydrogelation agents.


Assuntos
Compostos Ferrosos/química , Hidrogéis/química , Fenilalanina/análogos & derivados , Substâncias Macromoleculares/química , Modelos Moleculares , Conformação Molecular , Oxirredução , Tamanho da Partícula , Fenilalanina/química , Teoria Quântica , Propriedades de Superfície
11.
Colloids Surf B Biointerfaces ; 225: 113214, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36893664

RESUMO

Pharmacologically active natural products have played a significant role in the history of drug development. They have acted as sources of therapeutic drugs for various diseases such as cancer and infectious diseases. However, most natural products suffer from poor water solubility and low bioavailability, limiting their clinical applications. The rapid development of nanotechnology has opened up new directions for applying natural products and numerous studies have explored the biomedical applications of nanomaterials loaded with natural products. This review covers the recent research on applying plant-derived natural products (PDNPs) nanomaterials, including nanomedicines loaded with flavonoids, non-flavonoid polyphenols, alkaloids, and quinones, especially their use in treating various diseases. Furthermore, some drugs derived from natural products can be toxic to the body, so the toxicity of them is discussed. This comprehensive review includes fundamental discoveries and exploratory advances in natural product-loaded nanomaterials that may be helpful for future clinical development.


Assuntos
Produtos Biológicos , Nanopartículas , Sistemas de Liberação de Medicamentos , Nanotecnologia , Nanomedicina
12.
Science ; 380(6641): 192-198, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37053325

RESUMO

Mechanical nonreciprocity, or the asymmetric transmission of mechanical quantities between two points in space, is crucial for developing systems that can guide, damp, and control mechanical energy. We report a uniform composite hydrogel that displays substantial mechanical nonreciprocity, owing to direction-dependent buckling of embedded nanofillers. This material exhibits an elastic modulus more than 60 times higher when sheared in one direction compared with the opposite direction. Consequently, it can transform symmetric vibrations into asymmetric ones that are applicable for mass transport and energy harvest. Furthermore, it exhibits an asymmetric deformation when subjected to local interactions, which can induce directional motion of various objects, including macroscopic objects and even small living creatures. This material could promote the development of nonreciprocal systems for practical applications such as energy conversion and biological manipulation.

13.
Talanta ; 237: 122949, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736675

RESUMO

Heterogeneous analysis has great application prospects in the detection of post-translational modification (PTM) enzymes with the advantages of signal enhancement, less sample demand, and high sensitivity and selectivity. Nevertheless, once the substrate was fixed on a solid interface, the steric hindrance might limit the approaching of catalytic center to the substrate, thus reducing the efficiency of PTM. Herein, we suggested that the avidin-modified interface could be used to develop heterogeneous sensing platforms with biotin-labeled substrates as the probes, in which the enzymatic PTM was performed in solution and the heterogeneous assay was conducted on a solid surface. The sensing strategy integrates the advantages but overcomes the defects of both homogeneous and heterogeneous assays. Protein kinase A (PKA) and histone acetyltransferase (HAT) were determined as the examples by using sequence-specific peptide substrates. The signal changes were monitored by HRP-based colorimetric assay and antibody-amplified surface plasmon resonance (SPR). The methods were used for analysis of cell lysates and evaluation of inhibition efficiency with satisfactory results. The strategy can be used for the detection of a variety of biological enzymes and provide a new idea for the design of various heterogeneous biosensors. Thus, this work should be of great significance to the popularization and practical application of biosensors.


Assuntos
Técnicas Biossensoriais , Avidina , Biotina , Processamento de Proteína Pós-Traducional , Ressonância de Plasmônio de Superfície
14.
Carbohydr Polym ; 295: 119852, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35988978

RESUMO

This paper reports a versatile and dynamic hydrogel system based on ultrafast coordination between partially hydrogen-bonded (PHB) biopolymer hyaluronic acid and a series of transition metal ions at appropriate pH values. It was found that the procedure for the hydrogel synthesis was extremely facile, requiring a simple mixing of the components within 2 s. The hydrogels exhibited high water content, up to 96 %. Even so, the hydrogels can be stretched >50 times and rapidly self-heal from damage within only 10 s without using any healing agents or heating. Furthermore, this dynamic hydrogel network underwent reversible sol-gel transitions as response to multiple disparate stimuli, including pH, temperature, ions, redox, and light. The photo-patterning ability of the hydrogel with a rapid gel-sol transition upon exposure to light was also demonstrated. We disclosed the principle and methodology to use PHB metal-biopolymer systems for constructing dynamic bio-related soft matters.


Assuntos
Ácido Hialurônico , Hidrogênio , Hidrogéis/química , Íons , Metais
15.
Biosensors (Basel) ; 12(10)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36290946

RESUMO

Copper ions, as the active centers of natural enzymes, play an important role in many physiological processes. Copper ion-based catalysts which mimic the activity of enzymes have been widely used in the field of industrial catalysis and sensing devices. As an important class of small biological molecules, peptides have the advantages of easy synthesis, excellent biocompatibility, low toxicity, and good water solubility. The peptide-copper complexes exhibit the characteristics of low molecular weight, high tenability, and unique catalytic and photophysical properties. Biosensors with peptide-copper complexes as the signal probes have promising application prospects in environmental monitoring and biomedical analysis and diagnosis. In this review, we discussed the design and application of fluorescent, colorimetric and electrochemical biosensors based on the peptide-copper coordination interaction.


Assuntos
Técnicas Biossensoriais , Cobre , Cobre/química , Peptídeos/química , Íons , Água/química
16.
Front Aging Neurosci ; 14: 1060734, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36583188

RESUMO

Background: Robot-assisted therapy (RAT) has received considerable attention in stroke motor rehabilitation. Characteristics of brain functional response associated with RAT would provide a theoretical basis for choosing the appropriate protocol for a patient. However, the cortical response induced by RAT remains to be fully elucidated due to the lack of dynamic brain functional assessment tools. Objective: To guide the implementation of clinical therapy, this study focused on the brain functional responses induced by RAT in patients with different degrees of motor impairment. Methods: A total of 32 stroke patients were classified into a low score group (severe impairment, n = 16) and a high score group (moderate impairment, n = 16) according to the motor function of the upper limb and then underwent RAT training in assistive mode with simultaneous cerebral haemodynamic measurement by functional near-infrared spectroscopy (fNIRS). Functional connectivity (FC) and the hemisphere autonomy index (HAI) were calculated based on the wavelet phase coherence among fNIRS signals covering bilateral prefrontal, motor and occipital areas. Results: Specific cortical network response related to RAT was observed in patients with unilateral moderate-to-severe motor deficits in the subacute stage. Compared with patients with moderate dysfunction, patients with severe impairment showed a wide range of significant FC responses in the bilateral hemispheres induced by RAT with the assistive mode, especially task-related involvement of ipsilesional supplementary motor areas. Conclusion: Under assisted mode, RAT-related extensive cortical response in patients with severe dysfunction might contribute to brain functional organization during motor performance, which is considered the basic neural substrate of motor-related processes. In contrast, the limited cortical response related to RAT in patients with moderate dysfunction may indicate that the training intensity needs to be adjusted in time according to the brain functional state. fNIRS-based assessment of brain functional response assumes great importance for the customization of an appropriate protocol training in the clinical practice.

17.
J Colloid Interface Sci ; 606(Pt 1): 518-525, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34403861

RESUMO

Nickel iron hydroxides (NiFeOH) have been drawing enormous attention as effective catalysts for oxygen evolution reaction (OER), a key process in water splitting. Herein, we report that negatively charged iron(III) hydroxide colloidal particles, can significantly enhance the OER activity of NiFeOH in alkaline media. NiFeOH is grown on nickel foam in a supersaturated iron(III) salt solution, which also contains a high content of Fe(OH)3 colloidal nanoparticles, forming free-standing NiFeOH@Cx electrodes (with x being the Fe(OH)3 concentration). The interface between NiFeOH and Fe(OH)3 colloidal particles, as manifested by the unique volcano-like holes on the NiFeOH@Cx surface, is likely the OER active sites. In comparison to Fe(OH)3-free NiFeOH, NiFeOH@C1000 exhibits a 40-fold enhancement of the OER activity, confirming the significant effect of Fe(OH)3 colloidal nanoparticles in boosting the OER activity, likely as a result of enhanced charge transfer from Ni2+ to Fe3+ that facilitates the adsorption of key reaction intermediates. Furthermore, by coupling the free-standing NiFeOH@C1000 electrode with commercial Pt/C, full water splitting can occur and reach a current density of 10 mA cm-2 under a cell voltage of 1.51 V, which is lower than that (1.59 V) based on noble metal catalysts of RuO2 + Pt/C.

18.
Biosensors (Basel) ; 11(8)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34436082

RESUMO

The accurate analysis of circulating tumor cells (CTCs) holds great promise in early diagnosis and prognosis of cancers. However, the extremely low abundance of CTCs in peripheral blood samples limits the practical utility of the traditional methods for CTCs detection. Thus, novel and powerful strategies have been proposed for sensitive detection of CTCs. In particular, nanomaterials with exceptional physical and chemical properties have been used to fabricate cytosensors for amplifying the signal and enhancing the sensitivity. In this review, we summarize the recent development of nanomaterials-based optical and electrochemical analytical techniques for CTCs detection, including fluorescence, colorimetry, surface-enhanced Raman scattering, chemiluminescence, electrochemistry, electrochemiluminescence, photoelectrochemistry and so on.


Assuntos
Técnicas Biossensoriais , Células Neoplásicas Circulantes , Aptâmeros de Nucleotídeos , Contagem de Células , Técnicas Eletroquímicas , Fluorescência , Humanos , Nanoestruturas , Análise Espectral Raman
19.
Nanomaterials (Basel) ; 11(12)2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34947656

RESUMO

The physiochemical properties of nanomaterials have a close relationship with their status in solution. As a result of its better simplicity than that of pre-assembled aggregates, the in situ assembly of nanomaterials has been integrated into the design of electrochemical biosensors for the signal output and amplification. In this review, we highlight the significant progress in the in situ assembly of nanomaterials as the nanolabels for enhancing the performances of electrochemical biosensors. The works are discussed based on the difference in the interactions for the assembly of nanomaterials, including DNA hybridization, metal ion-ligand coordination, metal-thiol and boronate ester interactions, aptamer-target binding, electrostatic attraction, and streptavidin (SA)-biotin conjugate. We further expand the range of the assembly units from nanomaterials to small organic molecules and biomolecules, which endow the signal-amplified strategies with more potential applications.

20.
ACS Sens ; 6(3): 1166-1173, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33480678

RESUMO

This work proposed a new sensing strategy for protease detection by converting a homogeneous assay into a surface-tethered electrochemical analysis. Streptavidin (SA), a tetramer protein, was used as the sensing unit based on the SA-biotin coupling chemistry. Caspase-3 was used as the model analyte, and a biotinylated peptide with a sequence of biotin-GDEVDGK-biotin was designed as the substrate. Specifically, the peptide substrate could induce an assembly of SA to form (SA-biotin-GDEVDGK-biotin)n aggregates through SA-biotin interactions, which was confirmed by atomic force microscopy (AFM). The peptide substrate-induced assembly of SA was facilely initiated on an electrode-liquid surface by modification of the electrode with SA. The in situ formation of (SA-biotin-GDEVDGK-biotin)n aggregates created an insulating layer, thus limiting the electron transfer of ferricyanide. Once the peptide substrate was cleaved into two shorter fragments (biotin-GDEVD and GK-biotin) by caspase-3, the resulting products would compete with biotin-GDEVDGK-biotin to bind SA proteins immobilized on the electrode surface and distributed in a solution, thus preventing the in situ formation of (SA-biotin-GDEVDGK-biotin)n assemblies. With the simple principle of the substrate-induced assembly of SA, a dual-signal amplification was achieved with improved sensitivity. Taking advantage of high sensitivity, simple principle, and easy operation, this method can be augmented to design various surface-tethered biosensors for practical applications.


Assuntos
Técnicas Biossensoriais , Biotina , Técnicas Eletroquímicas , Peptídeo Hidrolases , Estreptavidina
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