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1.
Nanotechnology ; 35(36)2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38861939

RESUMEN

Surface plasmonic detectors have the potential to be key components of miniaturized chip-scale spectrometers. Graphene plasmons, which are highly confined and gate-tunable, are suitable forin situlight detection. However, the tuning of graphene plasmonic photodetectors typically relies on the complex and high operating voltage based on traditional dielectric gating technique, which hinders the goal of miniaturized and low-power consumption spectrometers. In this work, we report a tunable mid-infrared (MIR) photodetector by integrating of patterned graphene with non-volatile ferroelectric polarization. The polarized ferroelectric thin film provides an ultra-high surface electric field, allowing the Fermi energy of the graphene to be manipulated to the desired level, thereby exciting the surface plasmon polaritons effect, which is highly dependent on the free carrier density of the material. By exciting intrinsic graphene plasmons, the light transmittance of graphene is greatly enhanced, which improves the photoelectric conversion efficiency of the device. Additionally, the electric field on the surface of graphene enhanced by the graphene plasmons accelerates the carrier transfer efficiency. Therefore, the responsivity of the device is greatly improved. Our simulations show that the detectors have a tunable resonant spectral response of 9-14µm by reconstructing the ferroelectric domain and exhibit a high responsivity to 5.67 × 105A W-1at room temperature. Furthermore, we also demonstrate the conceptual design of photodetector could be used for MIR micro-spectrometer application.

2.
Sensors (Basel) ; 24(17)2024 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-39275419

RESUMEN

Photodetectors converting light into electrical signals are crucial in various applications. The pursuit of high-performance photodetectors with high sensitivity and broad spectral range simultaneously has always been challenging in conventional semiconductor materials. Graphene, with its zero bandgap and high electron mobility, is an attractive candidate, but its low light absorption coefficient restricts its practical application in light detection. Integrating graphene with light-absorbing materials like PbS quantum dots (QDs) can potentially enhance its photodetection capabilities. Here, this work presents a broadband photodetector with enhanced sensitivity based on a graphene-PbS QD heterostructure. The device leverages the high carrier mobility of graphene and the strong light absorption of PbS QDs, achieving a wide detection range from ultraviolet to near-infrared. Employing a simple spinning method, the heterostructure demonstrates ultrahigh responsivity up to the order of 107 A/W and a specific detectivity on the order of 1013 Jones, showcasing significant potential for photoelectric applications.

3.
Nucleic Acids Res ; 47(D1): D941-D947, 2019 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-30371878

RESUMEN

COSMIC, the Catalogue Of Somatic Mutations In Cancer (https://cancer.sanger.ac.uk) is the most detailed and comprehensive resource for exploring the effect of somatic mutations in human cancer. The latest release, COSMIC v86 (August 2018), includes almost 6 million coding mutations across 1.4 million tumour samples, curated from over 26 000 publications. In addition to coding mutations, COSMIC covers all the genetic mechanisms by which somatic mutations promote cancer, including non-coding mutations, gene fusions, copy-number variants and drug-resistance mutations. COSMIC is primarily hand-curated, ensuring quality, accuracy and descriptive data capture. Building on our manual curation processes, we are introducing new initiatives that allow us to prioritize key genes and diseases, and to react more quickly and comprehensively to new findings in the literature. Alongside improvements to the public website and data-download systems, new functionality in COSMIC-3D allows exploration of mutations within three-dimensional protein structures, their protein structural and functional impacts, and implications for druggability. In parallel with COSMIC's deep and broad variant coverage, the Cancer Gene Census (CGC) describes a curated catalogue of genes driving every form of human cancer. Currently describing 719 genes, the CGC has recently introduced functional descriptions of how each gene drives disease, summarized into the 10 cancer Hallmarks.


Asunto(s)
Bases de Datos de Ácidos Nucleicos , Mutación , Neoplasias/genética , Genes , Humanos , Conformación Proteica
4.
Sensors (Basel) ; 20(2)2020 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-31941128

RESUMEN

Detecting biomarkers is an efficient method to diagnose and monitor patients' stages. For more accurate diagnoses, continuously detecting and monitoring multiple biomarkers are needed. To achieve point-of-care testing (POCT) of multiple biomarkers, a smartphone biosensor system with the multi-testing-unit (SBSM) based on localized surface plasmon resonance (LSPR) integrated multi-channel microfluidics was presented. The SBSM could simultaneously record nine sensor units to achieve the detection of multiple biomarkers. Additional 72 sensor units were fabricated for further verification. Well-designed modularized attachments consist of a light source, lenses, a grating, a case, and a smartphone shell. The attachments can be well assembled and attached to a smartphone. The sensitivity of the SBSM was 161.0 nm/RIU, and the limit of detection (LoD) reached 4.2 U/mL for CA125 and 0.87 U/mL for CA15-3 through several clinical serum specimens testing on the SBSM. The testing results indicated that the SBSM was a useful tool for detecting multi-biomarkers. Comparing with the enzyme-linked immunosorbent assays (ELISA) results, the results from the SBSM were correlated and reliable. Meanwhile, the SBSM was convenient to operate without much professional skill. Therefore, the SBSM could become useful equipment for point-of-care testing due to its small size, multi-testing unit, usability, and customizable design.


Asunto(s)
Técnicas Biosensibles , Microfluídica , Teléfono Inteligente , Biomarcadores de Tumor/sangre , Calibración , Antígeno Carcinoembrionario/sangre , Oro/química , Humanos , Nanopartículas/química , Estadificación de Neoplasias , Estándares de Referencia , Refractometría , Resonancia por Plasmón de Superficie
5.
Small ; 15(9): e1804593, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30690881

RESUMEN

Cell lysis is an important and crucial step for the detection of intracellular secrets. Usually, cell lysis is based on strong ultrasonic waves or toxic chemical regents, which require a large amount of cell suspension. To obtain high efficiency cell lysis for a small amount of sample, a mechanical cell lysis method based on a surface acoustic wave (SAW) microchip is proposed. The microchip simply consists of a piece of LiNbO3 crystal substrate, interdigitated transducers (IDTs) with 80 pairs of parallel electrodes and 3M Magic Tapes. The modulated input electrical signal is coupled into the substrate through IDTs, which produces an acoustic stream in the droplet on the surface of a substrate. When a biofluid droplet containing cells and microparticles is dropped on the surface of the microchip, the cells and microparticles are accelerated and collide with each other. The fluorescence staining results illustrate that the cell membrane is efficiently destroyed and that proteins as well as nucleic acids inside the cell are released. The experimental results show that this method has a high efficiency and low sample consumption. The potential application is the pretreatment of a small amount of tested sample in a hospital or biolab.


Asunto(s)
Niobio/química , Óxidos/química , Sonido , Procedimientos Analíticos en Microchip , Ácidos Nucleicos/química
6.
Opt Express ; 27(10): 14152-14162, 2019 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-31163868

RESUMEN

Biosensors based on Rayleigh anomaly (RA) in metal gratings exhibit impressive bulk refractive index (RI) sensitivity and narrow linewidth. However, the electric field enhancement extends far away from surface of the gratings, which limits the application on biosensor where the RI changes are restricted at the sensor interface. To overcome this shortcoming, a novel grating composed of a 8-layer Au/Al2O3 stack was optimized by numerical simulation. The electric field is limited in several hundreds of nanometers from surface. The surface sensitivity increases 10 times than that of Au gratings at the detection depth of less than 400 nm. The surface index sensitivity can be improved 5 times under oblique incidence than that under normal incidence when the thickness of cover media is 20 nm.

7.
Langmuir ; 35(30): 9816-9824, 2019 07 30.
Artículo en Inglés | MEDLINE | ID: mdl-31268344

RESUMEN

Localized surface plasmon resonance-based plasmonic biosensors are interesting candidates for the design of portable optical biosensor platforms owing to their integration, miniaturization, multiparameter, real-time, and label-free detection characteristics. Plasmonic biosensor arrays that have been combined with microfluidics have been developed herein to detect exosomes label-free. Gold nano-ellipsoid arrays were fabricated with low-cost anodic aluminum oxide thin films that act as shadow masks for evaporation of Au. The nano-ellipsoid arrays were integrated with a microfluidic chip to achieve multiparameter detection. The anti-CD63 antibody that is specific to the exosome transmembrane protein CD63 is modified on the surface of the nano-ellipsoids. Exosome samples were injected into the biosensor platform at different concentrations and detected successfully. The detection limit was 1 ng/mL. The proposed plasmonic biosensor array can be universally applicable for the detection of other biomarkers by simply changing the antibody on the surface of the Au nano-ellipsoids. Moreover, this biosensor platform is envisaged to be potentially useful in the development of low-cost plasmonic-based biosensors for biomarker detection and for the investigation of exosomes for noninvasive disease diagnoses.


Asunto(s)
Costos y Análisis de Costo , Exosomas/metabolismo , Dispositivos Laboratorio en un Chip/economía , Resonancia por Plasmón de Superficie/instrumentación , Línea Celular , Humanos
8.
Nano Lett ; 18(4): 2243-2253, 2018 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-29517915

RESUMEN

Numerous studies have determined that physical cues, especially the nanotopography of materials, play key roles in directing stem cell differentiation. However, most research on nanoarrays for stem cell fate regulation is based on nonbiodegradable materials, such as silicon wafers, TiO2, and poly(methyl methacrylate), which are rarely used as tissue engineering biomaterials. In this study, we prepared biodegradable polylactic acid (PLA) nanopillar arrays with different diameters but the same center-to-center distance using a series of anodic aluminum oxide nanowell arrays as templates. Human adipose-derived stem cells (hADSCs) were selected to investigate the effect of the diameter of PLA nanopillar arrays on stem cell differentiation. By culturing hADSCs without the assistance of any growth factors or osteogenic-induced media, the differentiation tendencies of hADSCs on the nanopillar arrays were assessed at the gene and protein levels. The assessment results suggested that the osteogenic differentiation of hADSCs can be driven by nanopillar arrays, especially by nanopillar arrays with a diameter of 200 nm. Moreover, an in vivo animal model of the samples demonstrated that PLA film with the 200 nm pillar array exhibits an improved ectopic osteogenic ability compared with the planar PLA film after 4 weeks of ectopic implantation. This study has provided a new variable to investigate in the interaction between stem cells and nanoarray structures, which will guide the bone regeneration clinical research field. This work paves the way for the utility of degradable biopolymer nanoarrays with specific geometrical and mechanical signals in biomedical applications, such as patches and strips for spine fusion, bone crack repair, and restoration of tooth enamel.


Asunto(s)
Tejido Adiposo/citología , Nanoestructuras/química , Nanoestructuras/ultraestructura , Osteogénesis , Poliésteres/química , Células Madre/citología , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Humanos , Ingeniería de Tejidos/métodos , Andamios del Tejido/química
9.
Bioinformatics ; 32(23): 3654-3660, 2016 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-27522085

RESUMEN

MOTIVATION: High-throughput molecular profiling has greatly improved patient stratification and mechanistic understanding of diseases. With the increasing amount of data used in translational medicine studies in recent years, there is a need to improve the performance of data warehouses in terms of data retrieval and statistical processing. Both relational and Key Value models have been used for managing molecular profiling data. Key Value models such as SeqWare have been shown to be particularly advantageous in terms of query processing speed for large datasets. However, more improvement can be achieved, particularly through better indexing techniques of the Key Value models, taking advantage of the types of queries which are specific for the high-throughput molecular profiling data. RESULTS: In this article, we introduce a Collaborative Genomic Data Model (CGDM), aimed at significantly increasing the query processing speed for the main classes of queries on genomic databases. CGDM creates three Collaborative Global Clustering Index Tables (CGCITs) to solve the velocity and variety issues at the cost of limited extra volume. Several benchmarking experiments were carried out, comparing CGDM implemented on HBase to the traditional SQL data model (TDM) implemented on both HBase and MySQL Cluster, using large publicly available molecular profiling datasets taken from NCBI and HapMap. In the microarray case, CGDM on HBase performed up to 246 times faster than TDM on HBase and 7 times faster than TDM on MySQL Cluster. In single nucleotide polymorphism case, CGDM on HBase outperformed TDM on HBase by up to 351 times and TDM on MySQL Cluster by up to 9 times. AVAILABILITY AND IMPLEMENTATION: The CGDM source code is available at https://github.com/evanswang/CGDM. CONTACT: y.guo@imperial.ac.uk.


Asunto(s)
Biología Computacional/métodos , Genómica , Modelos Teóricos , Análisis por Conglomerados , Bases de Datos Genéticas , Humanos , Almacenamiento y Recuperación de la Información
10.
BMC Bioinformatics ; 15: 351, 2014 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-25371114

RESUMEN

BACKGROUND: High-throughput molecular profiling data has been used to improve clinical decision making by stratifying subjects based on their molecular profiles. Unsupervised clustering algorithms can be used for stratification purposes. However, the current speed of the clustering algorithms cannot meet the requirement of large-scale molecular data due to poor performance of the correlation matrix calculation. With high-throughput sequencing technologies promising to produce even larger datasets per subject, we expect the performance of the state-of-the-art statistical algorithms to be further impacted unless efforts towards optimisation are carried out. MapReduce is a widely used high performance parallel framework that can solve the problem. RESULTS: In this paper, we evaluate the current parallel modes for correlation calculation methods and introduce an efficient data distribution and parallel calculation algorithm based on MapReduce to optimise the correlation calculation. We studied the performance of our algorithm using two gene expression benchmarks. In the micro-benchmark, our implementation using MapReduce, based on the R package RHIPE, demonstrates a 3.26-5.83 fold increase compared to the default Snowfall and 1.56-1.64 fold increase compared to the basic RHIPE in the Euclidean, Pearson and Spearman correlations. Though vanilla R and the optimised Snowfall outperforms our optimised RHIPE in the micro-benchmark, they do not scale well with the macro-benchmark. In the macro-benchmark the optimised RHIPE performs 2.03-16.56 times faster than vanilla R. Benefiting from the 3.30-5.13 times faster data preparation, the optimised RHIPE performs 1.22-1.71 times faster than the optimised Snowfall. Both the optimised RHIPE and the optimised Snowfall successfully performs the Kendall correlation with TCGA dataset within 7 hours. Both of them conduct more than 30 times faster than the estimated vanilla R. CONCLUSIONS: The performance evaluation found that the new MapReduce algorithm and its implementation in RHIPE outperforms vanilla R and the conventional parallel algorithms implemented in R Snowfall. We propose that MapReduce framework holds great promise for large molecular data analysis, in particular for high-dimensional genomic data such as that demonstrated in the performance evaluation described in this paper. We aim to use this new algorithm as a basis for optimising high-throughput molecular data correlation calculation for Big Data.


Asunto(s)
Algoritmos , Perfilación de la Expresión Génica/métodos , Análisis por Conglomerados , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Programas Informáticos
11.
BMC Genomics ; 15 Suppl 8: S3, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25435347

RESUMEN

BACKGROUND: High-throughput transcriptomic data generated by microarray experiments is the most abundant and frequently stored kind of data currently used in translational medicine studies. Although microarray data is supported in data warehouses such as tranSMART, when querying relational databases for hundreds of different patient gene expression records queries are slow due to poor performance. Non-relational data models, such as the key-value model implemented in NoSQL databases, hold promise to be more performant solutions. Our motivation is to improve the performance of the tranSMART data warehouse with a view to supporting Next Generation Sequencing data. RESULTS: In this paper we introduce a new data model better suited for high-dimensional data storage and querying, optimized for database scalability and performance. We have designed a key-value pair data model to support faster queries over large-scale microarray data and implemented the model using HBase, an implementation of Google's BigTable storage system. An experimental performance comparison was carried out against the traditional relational data model implemented in both MySQL Cluster and MongoDB, using a large publicly available transcriptomic data set taken from NCBI GEO concerning Multiple Myeloma. Our new key-value data model implemented on HBase exhibits an average 5.24-fold increase in high-dimensional biological data query performance compared to the relational model implemented on MySQL Cluster, and an average 6.47-fold increase on query performance on MongoDB. CONCLUSIONS: The performance evaluation found that the new key-value data model, in particular its implementation in HBase, outperforms the relational model currently implemented in tranSMART. We propose that NoSQL technology holds great promise for large-scale data management, in particular for high-dimensional biological data such as that demonstrated in the performance evaluation described in this paper. We aim to use this new data model as a basis for migrating tranSMART's implementation to a more scalable solution for Big Data.


Asunto(s)
Sistemas de Administración de Bases de Datos , Bases de Datos Genéticas , Almacenamiento y Recuperación de la Información/métodos , Transcriptoma , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Informática Médica , Mieloma Múltiple/genética , Mieloma Múltiple/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos
12.
ACS Nano ; 18(3): 2117-2130, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38117205

RESUMEN

Alzheimer's disease (AD) is the most common cause of dementia in older people. However, diagnosing AD through noncognitive methods, such as invasive cerebrospinal fluid sampling or radioactive positron emission tomography, has limited applications. Herein, the femtomolar levels of AD biomarkers amyloid ß 40 (Aß40), amyloid ß 42 (Aß42), phosphorylated tau 181 (P-tau181), phosphorylated tau 217 (P-tau217), and neurofilament light chain (NfL) were determined in human plasma in multicenter clinical cohorts using an ultrasensitive graphene field-effect transistor sensor. A machine-learning algorithm was also used to assemble these plasma biomarkers and optimize their performance in discriminating individual stages of Alzheimer's dementia progression. The "composite-info" biomarker panel, which combines these biomarkers and clinical information, considerably improved the staging performance in AD progression. It achieved an area under the curve of >0.94 in the receiver operator characteristic (ROC) curve. In addition, the panel demonstrated an advantage in the individual-based stage assessment compared with that of the Mini-Mental State Examination/Montreal Cognitive Assessment and nuclear magnetic resonance imaging. This study provides a composite biomarker panel for the screening and early diagnosis of AD using a rapid detection system.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Anciano , Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides , Proteínas tau , Biomarcadores , Tomografía de Emisión de Positrones
13.
Micromachines (Basel) ; 12(2)2021 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-33498873

RESUMEN

Nanoimprint technology is powerful for fabricating nanostructures in a large area. However, expensive equipment, high cost, and complex process conditions hinder the application of nano-imprinting technology. Therefore, double-layer self-priming nanoimprint technology was proposed to fabricate ordered metal nanostructures uniformly on 4-inch soft and hard substrates without the aid of expensive instruments. Different nanostructure (gratings, nanoholes and nanoparticles) and different materials (metal and MoS2) were patterned, which shows wide application of double-layer self-priming nanoimprint technology. Moreover, by a double-layer system, the width and the height of metal can be adjusted through the photoresist thickness and developing condition, which provide a programmable way to fabricate different nanostructures using a single mold. The double-layer self-priming nanoimprint method can be applied in poor condition without equipment and be programmable in nanostructure parameters using a single mold, which reduces the cost of instruments and molds.

14.
Mater Sci Eng C Mater Biol Appl ; 116: 111233, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32806246

RESUMEN

Carbon dots (CDs) have shown great potential in drug delivery and biological imaging applications. In this work, a doxorubicin (DOX) delivery carrier and imaging probe for liver cancer-targeted therapy was designed based on CDs with high fluorescence quantum yield (97%), aiming to enhance the antitumor activity and imaging efficiency. Folic acid (FA), which showed high expression in hepatoma cells, was used as targeting components to modify CDs (FA-CDs), and then FA-CDs-DOX was obtained by loading DOX. Results show that CDs and FA-CDs have good biocompatibility, and the DOX release from FA-CDs-DOX is targeted and selective. Confocal microscope demonstrates that FA-CDs-DOX has excellent ability of fluorescence imaging in liver cancer cells. The imaging in vivo shows the fluorescence intensity of FA-CDs-DOX is strong enough to penetrate tumor tissue and skin, further verifying its enhanced-fluorescent imaging effects. Tumor inhibition in vivo indicates that the targeting ability of FA-CDs-DOX is significantly higher than that of free DOX, showing obvious better therapeutic effect. To sum up, the targeted and fluorescent drug delivery system based on CDs with high fluorescence quantum yield show an excellent imaging in vivo and tumor inhibition effect, which provide a novel strategy for promoting the potential clinical application of CDs in liver cancer treatment.


Asunto(s)
Carbono , Neoplasias Hepáticas , Doxorrubicina/farmacología , Sistemas de Liberación de Medicamentos , Ácido Fólico , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/tratamiento farmacológico
15.
Appl Biochem Biotechnol ; 186(3): 633-643, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29707732

RESUMEN

Cell migration and invasion are important factors during tumor progression and metastasis. Wound-healing assay and the Boyden chamber assay are efficient tools to investigate tumor development because both of them could be applied to measure cell migration rate. Therefore, a simple and integrated polydimethylsiloxane (PDMS) device was developed for cell migration assay, which could perform quantitative evaluation of cell migration behaviors, especially for the wound-healing assay. The integrated device was composed of three units, which included cell culture dish, PDMS chamber, and wound generation mold. The PDMS chamber was integrated with cell culture chamber and could perform six experiments under different conditions of stimuli simultaneously. To verify the function of this device, it was utilized to explore the tumor cell migration behaviors under different concentrations of fetal bovine serum (FBS) and transforming growth factor (TGF-ß) at different time points. This device has the unique capability to create the "wound" area in parallel during cell migration assay and provides a simple and efficient platform for investigating cell migration assay in biomedical application.


Asunto(s)
Técnicas de Cultivo de Célula/instrumentación , Ensayos de Migración Celular/instrumentación , Movimiento Celular , Dimetilpolisiloxanos/química , Neoplasias/patología , Línea Celular Tumoral , Medios de Cultivo , Diseño de Equipo , Humanos , Factor de Crecimiento Transformador beta/metabolismo , Cicatrización de Heridas
16.
J Colloid Interface Sci ; 509: 522-528, 2018 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-28967382

RESUMEN

Hydrophilic medium and precursors were used to synthesize a hydrophilic electro-catalyst for overall water splitting. The cobalt sulfide (Co3S4) catalyst exhibits a layered nanosheet structure with a hydrophilic surface, which can facilitate the diffusion of aqueous substrates into the electrode pores and towards the active sites. The Co3S4 catalyst shows excellent bifunctional catalytic activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. The assembled water electrolyzer based on Co3S4 exhibits better performance and stability than that of Pt/C-RuO2 catalyst. Thereforce the hydrophilic Co3S4 is a highly promising bifunctional catalyst for the overall water splitting reaction.

17.
Nanoscale ; 10(16): 7526-7535, 2018 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-29637947

RESUMEN

Although the synthesis and fluorescent properties of lanthanide-amino acid complex nanostructures have been investigated extensively, limited studies have been reported on metal ions' substitution ability for the lanthanide ions in the complex and their effect on the fluorescent property. In this study, taking biocompatible Tb-aspartic acid (Tb-Asp) complex nanocrystals as a model, the substitution mechanism of metal ions, particularly transition metals, for Tb ions in Tb-Asp nanocrystals and the change in the fluorescent property of the Tb-Asp nanocrystals after substitution were systematically investigated. The experimental results illustrated that metal ions with higher electronegativity, higher valence, and smaller radius possess stronger ability for Tb ions' substitution in Tb-Asp nanocrystals. Based on the effect of substituting ions' concentration on the fluorescent property of Tb-Asp, a facile method for copper ions detection with high sensitivity was proposed by measuring the fluorescent intensity of Tb-Asp nanocrystals' suspensions containing different concentrations of copper ions. The good biocompatibility, great convenience of synthesis and sensitive detection ability make Tb-Asp nanocrystals a very low cost and effective material for metal ions detection, which also opens a new door for practical applications of metal-Asp coordinated nanocrystals.


Asunto(s)
Ácido Aspártico/química , Materiales Biocompatibles/química , Cobre/análisis , Nanopartículas/química , Fluorescencia , Iones/análisis , Elementos de la Serie de los Lantanoides
18.
Acta Biomater ; 71: 108-117, 2018 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-29524672

RESUMEN

Controllable osteoinduction maintained in the original defect area is the key to precise bone repair. To meet the requirement of precise bone regeneration, a hydroxyapatite (HAp) nanobelt/polylactic acid (PLA) (HAp/PLA) Janus membrane has been successfully prepared in this study by coating PLA on a paper-like HAp nanobelt film by a casting-pervaporation method. The Janus membrane possesses dual functions: excellent osteoinduction from the hydrophilic HAp nanobelt side and barrier function originating from the hydrophobic PLA film. The cell viability and osteogenic differentiation ability of human adipose-derived stem cells (hADSCs) on the Janus membrane were assessed. The in vitro experimental results prove that the HAp nanobelt side presents high cell viability and efficient osteoinduction without any growth factor and that the PLA side can prohibit cell attachment. The in vivo repair experiments on a rat mandible defect model prove that the PLA side can prevent postoperative adhesion between bone and adjacent soft tissues. Most importantly, the HAp side has a strong ability to promote defect repair and bone regeneration. Therefore, the HAp/PLA Janus membrane will have wide applications as a kind of tissue engineering material in precise bone repair because of its unique dual osteoinduction/barrier functions, biocompatibility, low cost, and its ability to be mass-produced. STATE OF SIGNIFICANCE: Precise bone defect repair to keeping tissue integrity and original outline shape is a very important issue for tissue engineering. Here, we have designed and prepared a novel HAp/PLA Janus membrane using a casting-pervaporation method to form a layer of PLA film on paper-like HAp nanobelt film. HAp nanobelt side of the Janus membrane can successfully promote osteogenic differentiation. PLA side of the Janus membrane exhibits good properties as a barrier for preventing the adhesion of cells in vitro. Mandible repair experiments in vivo have shown that the HAp/PLA Janus membrane can promote rat mandible repair on the HAp side and can successfully prevent postoperative adhesion on the PLA side at the same time. Therefore, the HAp/PLA Janus membrane with its osteoinduction/barrier dual functions can be applied to repair bone defect precisely.


Asunto(s)
Regeneración Ósea/efectos de los fármacos , Huesos , Durapatita , Membranas Artificiales , Nanoestructuras , Osteogénesis/efectos de los fármacos , Animales , Huesos/lesiones , Huesos/metabolismo , Huesos/patología , Durapatita/química , Durapatita/farmacología , Humanos , Nanoestructuras/química , Nanoestructuras/uso terapéutico , Ratas , Ratas Wistar
19.
Sci Rep ; 7(1): 8963, 2017 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-28827722

RESUMEN

Tumour cell migration has an important impact on tumour metastasis. Magnetic manipulation is an ascendant method for guiding and patterning cells. Here, a unique miniaturized microfluidic chip integrating cell isolation and migration assay was designed to isolate and investigate cell migration. The chip was fabricated and composed of a magnet adapter, a polytetrafluoroethylene(PDMS) microfluidic chip and six magnetic rings. This device was used to isolate MCF-7 cells from MDA-MB-231-RFP cells and evaluate the effects of TGF-ß on MCF-7 cells. First, the two cell types were mixed and incubated with magnetic beads modified with an anti-EpCAM antibody. Then, they were slowly introduced into the chip. MCF-7 cells bond to the magnetic beads in a ring-shaped pattern, while MDA-MB-231-RFP cells were washed away by PBS. Cell viability was examined during culturing in the micro-channel. The effects of TGF-ß on MCF-7 cells were evaluated by migration distance and protein expression. The integrated method presented here is novel, low-cost and easy for performing cell isolation and migration assay. The method could be beneficial for developing microfluidic device applications for cancer metastasis research and could provide a new method for biological experimentation.


Asunto(s)
Movimiento Celular , Células Epiteliales/efectos de los fármacos , Células Epiteliales/fisiología , Separación Inmunomagnética/métodos , Microfluídica/métodos , Factor de Crecimiento Transformador beta/metabolismo , Femenino , Humanos , Separación Inmunomagnética/instrumentación , Células MCF-7 , Microfluídica/instrumentación
20.
Nanoscale ; 9(6): 2162-2171, 2017 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-27849086

RESUMEN

Carbon quantum dots (CQDs) are a new type of fluorescent nanoparticle for cell imaging and tracking. However, they would easily diffuse and quench, followed by the loss of their fluorescence ability. By connecting their functional groups with other nanoparticles, the CQDs will be protected from destruction and exhibit long-time fluorescence. Here, carbon quantum dot-hydroxyapatite (CQD-HAp) hybrid nanorods were prepared by the self-assembly of CQDs on the surface of HAp nanorods through a facile one-pot process. The morphology and size of the CQD-HAp hybrid nanorods can be well controlled by using oleic acid, which meanwhile is the source of CQDs. The hydrophilic CQD-HAp hybrid nanorods have prolonged fluorescence life due to the connection between CQDs and HAp nanorods, and exhibit a higher fluorescence quantum yield than pure CQDs. In addition, when hybrid nanorods load doxorubicin (Dox) to form Dox-CQD-HAp hybrid nanorods, they can more efficiently kill human cervical cancer (HeLa) cells, rather than human prostatic cancer (PC-3) cells. Long time fluorescence for cell imaging and high efficiency in killing cancer cells as a drug-delivery medium make CQD-HAp hybrid nanorods have great potential applications in the bio-field.


Asunto(s)
Carbono/química , Fluorescencia , Puntos Cuánticos/química , Línea Celular Tumoral , Doxorrubicina/administración & dosificación , Portadores de Fármacos , Durapatita , Células HeLa , Humanos , Nanotubos
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