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2.
Virchows Arch ; 475(3): 313-323, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31267199

RESUMO

Breast cancer is a highly heterogeneous disease. The efficacy of tailored therapeutic strategies relies on the precise detection of diagnostic biomarkers by immunohistochemistry (IHC). Therefore, considering the increasing incidence of breast cancer cases, a concomitantly time-efficient and accurate diagnosis is clinically highly relevant. Microfluidics is a promising innovative technology in the field of tissue diagnostic, enabling for rapid, reliable, and automated immunostaining. We previously reported the microfluidic-based HER2 (human epidermal growth factor receptor 2) detection in breast carcinomas to greatly correlate with the HER2 gene amplification level. Here, we aimed to develop a panel of microfluidic-based IHC protocols for prognostic and therapeutic markers routinely assessed for breast cancer diagnosis, namely HER2, estrogen/progesterone receptor (ER/PR), and Ki67 proliferation factor. The microfluidic IHC protocol for each marker was optimized to reach high staining quality comparable to the standard procedure, while concomitantly shortening the staining time to 16 min-excluding deparaffinization and antigen retrieval step-with a turnaround time reduction up to 7 folds. Comparison of the diagnostic score on 50 formaldehyde-fixed paraffin-embedded breast tumor resections by microfluidic versus standard staining showed high concordance (overall agreement: HER2 94%, ER 95.9%, PR 93.6%, Ki67 93.7%) and strong correlation (ρ coefficient: ER 0.89, PR 0.88, Ki67 0.87; p < 0.0001) for all the analyzed markers. Importantly, HER2 genetic reflex test for all discordant cases confirmed the scores obtained by the microfluidic technique. Overall, the microfluidic-based IHC represents a clinically validated equivalent approach to the standard chromogenic staining for rapid, accurate, and automated breast cancer diagnosis.


Assuntos
Neoplasias da Mama/diagnóstico , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/métodos , Biomarcadores Tumorais/metabolismo , Mama/patologia , Feminino , Humanos , Imuno-Histoquímica/métodos , Hibridização in Situ Fluorescente , Antígeno Ki-67/metabolismo , Prognóstico , Receptor ErbB-2/metabolismo , Receptores Estrogênicos/metabolismo , Receptores de Progesterona/metabolismo
4.
Anal Bioanal Chem ; 411(21): 5415-5422, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31317237

RESUMO

Isoelectric focusing (IEF), a powerful technique for protein separation and enrichment, was successfully integrated into microfluidic paper-based analytical devices (µPADs) in this work. The µPADs for isoelectric focusing were fabricated by octadecyltrichlorosilane (OTS) silanization and subsequent region-selective plasma treatment. The system of IEF on µPADs could be easily assembled. And a series of conditions of the system were investigated, including the suitable concentration of ampholyte to create good pH gradient, the effect of polyvinylpyrrolidone (PVP) on electroosmotic flow (EOF) suppression, and focusing voltage applied on the paper channel. After optimization, simultaneous separation and enrichment of protein sample containing myoglobin and cytochrome C was successfully demonstrated. Besides, parallel IEF on multichannels were also achieved for the separation of multiple protein samples on one single chip, and their performance was compared with that of the conventional gel-IEF system. The developed IEF on µPADs exhibits appealing features such as low cost, simplicity, and disposability and are believed to have great application potentials.


Assuntos
Focalização Isoelétrica , Técnicas Analíticas Microfluídicas/métodos , Papel , Citocromos c/isolamento & purificação , Eletro-Osmose , Concentração de Íons de Hidrogênio , Mioglobina/isolamento & purificação , Povidona/química , Silanos/química
6.
Nat Genet ; 51(6): 1060-1066, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31152164

RESUMO

Modulation of chromatin structure via histone modification is a major epigenetic mechanism and regulator of gene expression. However, the contribution of chromatin features to tumor heterogeneity and evolution remains unknown. Here we describe a high-throughput droplet microfluidics platform to profile chromatin landscapes of thousands of cells at single-cell resolution. Using patient-derived xenograft models of acquired resistance to chemotherapy and targeted therapy in breast cancer, we found that a subset of cells within untreated drug-sensitive tumors share a common chromatin signature with resistant cells, undetectable using bulk approaches. These cells, and cells from the resistant tumors, have lost chromatin marks-H3K27me3, which is associated with stable transcriptional repression-for genes known to promote resistance to treatment. This single-cell chromatin immunoprecipitation followed by sequencing approach paves the way to study the role of chromatin heterogeneity, not just in cancer but in other diseases and healthy systems, notably during cellular differentiation and development.


Assuntos
Neoplasias da Mama/genética , Imunoprecipitação da Cromatina , Cromatina/genética , Heterogeneidade Genética , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Célula Única , Cromatina/metabolismo , Biologia Computacional/métodos , Epigênese Genética , Feminino , Histonas/metabolismo , Humanos , Técnicas Analíticas Microfluídicas , Análise de Célula Única/métodos , Células Estromais , Fluxo de Trabalho
7.
Nat Neurosci ; 22(7): 1075-1088, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31209379

RESUMO

Microglia rapidly respond to changes in neural activity and inflammation to regulate synaptic connectivity. The extracellular signals, particularly neuron-derived molecules, that drive these microglial functions at synapses remain a key open question. Here we show that whisker lesioning, known to dampen cortical activity, induces microglia-mediated synapse elimination. This synapse elimination is dependent on signaling by CX3CR1, the receptor for microglial fractalkine (also known as CXCL1), but not complement receptor 3. Furthermore, mice deficient in CX3CL1 have profound defects in synapse elimination. Single-cell RNA sequencing revealed that Cx3cl1 is derived from cortical neurons, and ADAM10, a metalloprotease that cleaves CX3CL1 into a secreted form, is upregulated specifically in layer IV neurons and in microglia following whisker lesioning. Finally, inhibition of ADAM10 phenocopies Cx3cr1-/- and Cx3cl1-/- synapse elimination defects. Together, these results identify neuron-to-microglia signaling necessary for cortical synaptic remodeling and reveal that context-dependent immune mechanisms are utilized to remodel synapses in the mammalian brain.


Assuntos
Proteína ADAM10/fisiologia , Secretases da Proteína Precursora do Amiloide/fisiologia , Receptor 1 de Quimiocina CX3C/fisiologia , Quimiocina CX3CL1/fisiologia , Proteínas de Membrana/fisiologia , Microglia/fisiologia , Córtex Sensório-Motor/fisiopatologia , Tato/fisiologia , Vibrissas/lesões , Proteína ADAM10/antagonistas & inibidores , Proteína ADAM10/genética , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/genética , Animais , Receptor 1 de Quimiocina CX3C/deficiência , Receptor 1 de Quimiocina CX3C/genética , Contagem de Células , Feminino , Regulação da Expressão Gênica , Masculino , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Técnicas Analíticas Microfluídicas , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Córtex Sensório-Motor/metabolismo , Córtex Sensório-Motor/patologia , Transdução de Sinais/fisiologia , Análise de Célula Única , Transcriptoma , Vibrissas/fisiologia
8.
Nat Commun ; 10(1): 2741, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227695

RESUMO

Knowing how biomarker levels vary within biological fluids over time can produce valuable insight into tissue physiology and pathology, and could inform personalised clinical treatment. We describe here a wearable sensor for monitoring biomolecule levels that combines continuous fluid sampling with in situ analysis using wet-chemical assays (with the specific assay interchangeable depending on the target biomolecule). The microfluidic device employs a droplet flow regime to maximise the temporal response of the device, using a screw-driven push-pull peristaltic micropump to robustly produce nanolitre-sized droplets. The fully integrated sensor is contained within a small (palm-sized) footprint, is fully autonomous, and features high measurement frequency (a measurement every few seconds) meaning deviations from steady-state levels are quickly detected. We demonstrate how the sensor can track perturbed glucose and lactate levels in dermal tissue with results in close agreement with standard off-line analysis and consistent with changes in peripheral blood levels.


Assuntos
Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito , Pele/química , Dispositivos Eletrônicos Vestíveis , Biomarcadores/análise , Glicemia/análise , Desenho de Equipamento , Glucose/análise , Voluntários Saudáveis , Humanos , Ácido Láctico/análise , Microdiálise/instrumentação , Microdiálise/métodos , Técnicas Analíticas Microfluídicas/métodos
9.
Talanta ; 202: 384-391, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171199

RESUMO

A novel microfluidic paper-based analytical device (µPAD) was developed with benzoquinone (BQ)-mediated E. coli respiration method to measure the biotoxicities of pollutants. Functional units including sample injection, fluid-cell separation, all-carbon electrode-enabled electrochemical detection, were integrated on a piece of chromatography paper. The three-electrode, working electrode, counter electrode and reference electrode, were simultaneously screen-printed on the µPAD with conductive carbon ink. The satisfying electrochemical performance of the paper-based carbon three-electrode was confirmed by cyclic voltammetry detecting K3 [Fe(CN)6]. The process of cell toxication was considered that toxicants inhibited cell respiration and diminished the electrons on E. coli respiratory chain. It was quantitatively reflected by measuring oxidation current of hydroquinone (HQ) as a reduced state of the redox mediator BQ after the incubation of cells with pollutants. The current detection time, BQ concentration and E. coli incubation time were carefully optimized to establish the systematic optimized operations of BQ-mediated E. coli respiration method. Using the fabricated µPAD the half inhibitory concentration (IC50) were Cu2+ solution 13.5 µg mL-1, Cu2+-soil 21.4 mg kg-1, penicillin sodium-soil 85.1 mg kg-1, and IC30 of Pb2+ solution was 60.0 µg mL-1. Detection of pesticide residues in vegetable juices were accomplished in a similar way. The proposed method is fascinating on three points; 1) The generality in the biotoxicity detection depends on toxicants inducing cellular respiratory inhibition; 2) The portability and affordability make it convenient for practical applications, because of replacing incubators and centrifuges; 3) There is potential applicability in less-developed areas due to its simple operation and low-cost.


Assuntos
Técnicas Eletroquímicas , Poluentes Ambientais/farmacologia , Escherichia coli/efeitos dos fármacos , Técnicas Analíticas Microfluídicas , Papel , Benzoquinonas/química , Eletrodos , Poluentes Ambientais/análise , Escherichia coli/citologia , Escherichia coli/metabolismo
10.
Talanta ; 202: 96-110, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171232

RESUMO

Along with the considerable potential and increasing demand of the point-of-care testing (POCT), corresponding detection platforms have attracted great interest in both academic and practical fields. The first few generations of conventional detection devices tend to be costly, complicated to operate and hard to move on account of early limitations in the level of technological development and relatively high requirement of performance. Owing to the requirements for rapidity, simplicity, accuracy and cost controlling in the POCT, reader systems are urgently needed to be developed, upgraded and modified constantly, realizing on-site testing and healthcare management without a specific place or cumbersome operation. Accordingly, numerous rapid detection platforms with diverse size and performance have emerged such as bench-top apparatuses, handheld devices and intelligent detection devices. This review discusses various devices developed mainly for the detection of lateral flow test strips (LFTSs) or microfluidic strips in the POCT and summarizes these devices by size and portability. Furthermore, on the basis of various detection methods and diverse probes usually containing specific nanoparticles composites, three most common aspects of detection rationale in the POCT are selected to elaborate each kind of detection platforms in this paper: colorimetric assay, luminescent detection and magnetic signal detection. Herein, we focus on their structures, detection mechanisms and assay results, accompany with discussions and comments on the performances, costs and potential application, as well as advantages and limitations of each technique. In addition, perspectives on the future advances of detection platforms and some conclusions are proposed.


Assuntos
Colorimetria , Medições Luminescentes , Técnicas Analíticas Microfluídicas , Testes Imediatos , Humanos , Espectroscopia de Ressonância Magnética , Nanopartículas/química
11.
Chem Asian J ; 14(14): 2491-2496, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31087617

RESUMO

Microshells are attractive in constructing bubble-propelled micromotors due to the lower energy consumption for bubbles forming on a concave surface. In this work, enzyme-powered microshell motors were fabricated on multimetallic (Au/Ag/Au) microshells along with the modification of catalase on its concave surface. The catalase triggered the decomposition of hydrogen peroxide to oxygen gas, hence propelling the autonomous motion of microshell motors. A size-dependent motion behaviour was observed for the microshell motors in the form of slow tremble and fast translation motion for a size smaller and larger than 5 µm, respectively, according to the size, generation efficiency and ejection mechanism of bubbles and the intensity of Brownian motion. In addition, the effect of fuel concentration on the motion speed of microshells was dependent on whether the bubble generation was affected by the limited mass transfer in the microshell space. These findings play an important role for the design of microshell motors.


Assuntos
Catalase/química , Glucose Oxidase/química , Técnicas Analíticas Microfluídicas , Catalase/metabolismo , Glucose Oxidase/metabolismo , Ouro/química , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Técnicas Analíticas Microfluídicas/instrumentação , Tamanho da Partícula , Prata/química , Propriedades de Superfície
12.
Analyst ; 144(11): 3556-3566, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31050348

RESUMO

Haematological diseases significantly increase RBC aggregation. Specifically, RBC aggregation is considerably varied by haematological factors including cellular properties, and suspending medium properties. Thus, in order to ensure consistent measurement of RBC aggregation, it is necessary to measure RBC aggregation and blood pressure simultaneously. Here, a method for simultaneously measuring RBC aggregation and blood pressure is demonstrated by analyzing blood flows supplied from a disposable air-compressed pump. A microfluidic device is composed of two parallel microfluidic channels (i.e., PBS channel and blood channel), an inlet, and outlets. After the PBS channel is filled with the PBS solution, the outlets of the PBS channel are completely closed with two pinch valves. Under varying blood flow rates of the disposable pump, the blood pressure index (PI) is quantified by analyzing the image intensity of RBCs in the PBS channel. Thereafter, at stasis, the RBC aggregation index (AI) is calculated by analyzing the image intensity of blood in the blood channel. First, under a constant blood flow-rate of a syringe pump, the image intensity of RBCs collected in the PBS channel (IPC) is linearly proportional to blood pressure estimated in the blood channel (PBC). Second, with respect to variations in the blood flow-rate of the proposed pump, the IPC and PBC decrease gradually over time. Two blood pressure indices (PI [PBC], and PI [IPC]) are obtained by averaging temporal variations in the PBC and IPC, respectively. The results of the regression analysis indicate that the coefficient of the linear regression yields a higher value of R2 = 0.9051. Subsequently, the PI (IPC) is effectively used to estimate blood pressure. Finally, the variations in blood pressure and RBC aggregation are obtained by using aggregation-enhanced blood samples and deformability-reduced blood samples. Thus, the proposed method leads to consistent variations in the PI and AI, when compared with the previous results. The experimental demonstrations indicate that two indices (PI and AI) are effectively used to simultaneously quantify blood pressure and RBC aggregation.


Assuntos
Pressão Sanguínea , Agregação Eritrocítica , Técnicas Analíticas Microfluídicas/métodos , Desenho de Equipamento , Hematócrito , Humanos , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Análise de Regressão
13.
Anal Chim Acta ; 1071: 36-43, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31128753

RESUMO

This study describes for the first time the development of 3D printed microfluidic devices with integrated electrodes for label-free counting of E. coli cells incorporated inside droplets based on capacitively coupled contactless conductivity detection (C4D). Microfluidic devices were fully fabricated by 3D printing in the T-junction shape containing two channels for disperse and continuous phases and two sensing electrodes for C4D measurements. The disperse phase containing E. coli K12 cells and the continuous phase containing oil and 1% Span® 80 were pumped through flow rates fixed at 5 and 60 µL min-1, respectively. The droplets with incorporated cells were monitored in the C4D system applying a 500-kHz sinusoidal wave with 1 Vpp amplitude. The generated droplets exhibited a spherical shape with average diameter of 321 ±â€¯9 µm and presented volume of 17.3 ±â€¯0.5 nL. The proposed approach demonstrated ability to detect E. coli cells in the concentration range between 86.5 and 8650 CFU droplet-1. The number of cells per droplet was quantified through the plate counting method and revealed a good agreement with the Poisson distribution. The limit of detection achieved for counting E. coli cells was 63.66 CFU droplet-1. The label-free counting method has offered instrumental simplicity, low cost, high sensitivity and compatibility to be integrated on single microfluidic platforms entirely fabricated by 3D printing, thus opening new possibilities of applications in microbiology.


Assuntos
Contagem de Células/métodos , Condutividade Elétrica , Técnicas Eletroquímicas/métodos , Escherichia coli K12/isolamento & purificação , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/métodos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Limite de Detecção , Técnicas Analíticas Microfluídicas/instrumentação , Impressão Tridimensional
14.
Anal Chim Acta ; 1071: 44-52, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31128754

RESUMO

A multifunctional microchip-based distillation apparatus is presented for the distilled of sulfur dioxide (SO2) in food products. The microchip is fabricated on poly(methyl methacrylate) (PMMA) substrates, and comprises a sample zone, a buffer zone, a serpentine distillation column, and a collection zone. In the process, the sample is introduced into the sample zone and is heated under carefully controlled temperature and time conditions. The resulting SO2 and water vapor are carried by nitrogen (N2) gas to the distillation column, where the SO2 is separated from the water vapor via the condensing effects of a continuous cold water flow. Finally, the SO2 is transported to the collection zone, where it is collected with hydrogen peroxide (H2O2) and its concentration determined using an alkali-based titration and paper-based detection method. A distillation efficiency of 90.5% is obtained under the optimal distillation conditions at concentrations of 20-4000 ppm. Moreover, a linear correlation (R2 = 0.9997) is observed between the experimental measurements of the SO2 concentration and the known concentration. The validity of the presented microchip-based distillation apparatus is further investigated by distilling the SO2 concentrations of 25 commodity samples. The detection results show that the deviation does not exceed 5.4% compared with the traditional official method.


Assuntos
Destilação/métodos , Técnicas Analíticas Microfluídicas/métodos , Dióxido de Enxofre/análise , Destilação/instrumentação , Contaminação de Alimentos/análise , Frutas/química , Dispositivos Lab-On-A-Chip , Limite de Detecção , Técnicas Analíticas Microfluídicas/instrumentação , Polimetil Metacrilato/química , Verduras/química
15.
Anal Chim Acta ; 1071: 59-69, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31128756

RESUMO

Early diagnosis of cancer by biomarker detection has been widely studied since it can lead to an increase in patient survival rates. Magnetic nanoparticles (MNPs) play an important role in this field acting as a valuable tool in the biomarker immunocapture and detection. In this work, Co0.25Zn0.75Fe2O4 (CoZnFeONPs) nanoparticles were synthesized and applied as enzyme mimics of peroxidase-like catalysis in a disposable enzyme-free microfluidic immunoarray device (µID). The catalytic activity of CoZnFeONPs was evaluated by hydrogen peroxide detection using cyclic voltammetry and the apparent Michaelis-Menten constant was estimated by Lineweaver-Burk equation showing good Km values. In µID, the immunosensors were assembled with monoclonal antibody against CYFRA 21-1 covalently immobilized on graphene oxide previously deposited on the screen-printed carbon-based electrodes. Under optimized conditions, the method presented a good linear response for CYFRA 21-1 in the range of 3.9-1000 fg mL-1 achieving an ultralow limit of detection (LOD) of 0.19 fg mL-1. For comparison, Fe3O4 nanoparticles (FeONPs) was also synthetized and presented results slight inferior to that obtained with CoZnFeONPs. The methods developed using both MNPs exhibited countless advantages when compared with the immunosensors developed for CYFRA-21-1, previously reported in the literature. The methods were successful applied for the detection of CYFRA 21-1 in real serum samples of healthy and prostate cancer patients and showed good correlation with results obtained with the enzyme-linked immunosorbent assay (ELISA). The CoZnFeONPs associated with the disposable microfluidic immunoarray device provides a simple and effective method for biomarker detection that could satisfy the need for a low-cost and rapid test for early diagnosis of cancer.


Assuntos
Antígenos de Neoplasias/sangue , Biomarcadores Tumorais/sangue , Queratina-19/sangue , Dispositivos Lab-On-A-Chip , Nanopartículas Metálicas/química , Técnicas Analíticas Microfluídicas/métodos , Anticorpos/imunologia , Antígenos de Neoplasias/imunologia , Biomarcadores Tumorais/imunologia , Cobalto/química , Eletrodos , Grafite/química , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Ferro/química , Queratina-19/imunologia , Limite de Detecção , Masculino , Técnicas Analíticas Microfluídicas/instrumentação , Neoplasias da Próstata/sangue , Reprodutibilidade dos Testes , Zinco/química
16.
Analyst ; 144(12): 3782-3789, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31094378

RESUMO

We investigate the influence of rotational forces on blood dynamics in a microfluidic device. The special confluence of Coriolis force and blood rheology is brought forth by analyzing the flow at different hematocrit (volume fraction of red blood cells) levels and rotational speeds. We further study the effects of channel layout and alignment with regard to the axis of rotation to understand this intricate interplay. We provide a sound basis for efficient designing of a lab on a compact disc (lab on CD) platform by harnessing the effects of Coriolis force at relatively much lower rotational speeds, in sharp contrast with the reported findings where Coriolis effects have been considered to be effective only for exceptionally high rotational speeds. Our results show that over certain intermediate regimes of rotational speeds, the flow profiles for different hematocrit levels are noticeably different. This, in turn, could be harnessed as a possible diagnostic signature of the hematocrit (or equivalently, packed cell volume) level, without necessitating the deployment of chemical consumables, in an energy efficient paradigm.


Assuntos
Sangue , Discos Compactos , Força Coriolis , Hematócrito/métodos , Dispositivos Lab-On-A-Chip , Viscosidade Sanguínea , Hematócrito/instrumentação , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Rotação
17.
J Nanobiotechnology ; 17(1): 71, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133019

RESUMO

The incidence of lung cancer continues to rise worldwide. Because the aggressive metastasis of lung cancer cells is the major drawback of successful therapies, the crucial challenge of modern nanomedicine is to develop diagnostic tools to map the molecular mechanisms of metastasis in lung cancer patients. In recent years, microfluidic platforms have been given much attention as tools for novel point-of-care diagnostic, an important aspect being the reconstruction of the body organs and tissues mimicking the in vivo conditions in one simple microdevice. Herein, we present the first comprehensive overview of the microfluidic systems used as innovative tools in the studies of lung cancer metastasis including single cancer cell analysis, endothelial transmigration, distant niches migration and finally neoangiogenesis. The application of the microfluidic systems to study the intercellular crosstalk between lung cancer cells and surrounding tumor microenvironment and the connection with multiple molecular signals coming from the external cellular matrix are discussed. We also focus on recent breakthrough technologies regarding lab-on-chip devices that serve as tools for detecting circulating lung cancer cells. The superiority of microfluidic systems over traditional in vitro cell-based assays with regard to modern nanosafety studies and new cancer drug design and discovery is also addressed. Finally, the current progress and future challenges regarding printable and paper-based microfluidic devices for personalized nanomedicine are summarized.


Assuntos
Neoplasias Pulmonares/diagnóstico , Técnicas Analíticas Microfluídicas/métodos , Nanoestruturas/química , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Materiais Biomiméticos/química , Movimento Celular , Humanos , Dispositivos Lab-On-A-Chip , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/patologia , Técnicas Analíticas Microfluídicas/instrumentação , Nanomedicina , Nanoestruturas/efeitos adversos , Metástase Neoplásica , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Nanomedicina Teranóstica , Microambiente Tumoral
18.
Anal Chim Acta ; 1068: 41-51, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31072476

RESUMO

Foodborne pathogens pose one of the greatest challenges facing public health in the modern day. One important pathogen, Listeria monocytogenes, is known to be challenging to detect and identify. Three serovars cause most of the Listeria related food-borne illnesses, which the Centers for Disease Control currently utilizes a combination of pulsed-field gel electrophoresis and whole genome sequencing for identification and the determination of clusters and outbreaks. There is a potential method for rapid collection of epidemiological information by exploiting the electrokinetic and dielectrophoretic properties of the L. monocytogenes serovars. Using dielectrophoresis, the three most commonly identified serovars of L. monocytogenes can be distinguished from each other. The electrokinetic and dielectrophoretic mobilities of each serovar was determined through a combination of electrokinetic velocity and dielectrophoretic trapping assessments, in conjunction with finite element multi-physics modeling. A mathematical model of the data, which defines the various factors of dielectrophoretic trapping, is utilized and verified based on the behavior of L. monocytogenes in the microchannel. The trapping condition for the serovars were evaluated as 2.8±0.2×109, 2.2±0.2×109, and 2.2±0.3×109Vm-2 and the electrokinetic mobility was assessed to be 19±0.7, 17±0.7, and for the L. monocytogenes serovars 1/2a, 1/2b, and 4b, respectively.


Assuntos
Listeria monocytogenes/isolamento & purificação , Eletroforese , Listeria monocytogenes/citologia , Técnicas Analíticas Microfluídicas
19.
Talanta ; 200: 169-176, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036170

RESUMO

Circulating tumor cells (CTCs) are rare cancer cells that are shed from the tumors into the peripheral blood and are instrumental in distant metastasis. Early detection of CTCs can therefore improve prognoses and help design patient-specific treatment regimen. However, the current CTC isolation techniques have poor efficacy and selectivity, owing to the rarity and heterogeneity of the CTCs. We designed a microchip for integrated single-cell isolation of CTCs - based on cell size and immuno-phenotype - and analysis. Each isolation unit consisted of a trap channel, a bypass channel, and a release channel. The larger cells were preferentially captured at the trap channels and flushed out selectively via release microvalves according to their immuno-phenotype. The average recovery rate and purity of lung cancer cells isolated from a spiked WBC population were respectively 92.5% and 94% using the microchip, which were significantly higher compared to that obtained using anti-CD45 magnetic beads. In addition, the isolated cancer cells were analyzed on chip for the surface markers of epithelial mesenchymal transition. Taken together, the integrated microchip is a promising tool for the isolation and analysis of CTCs in the clinical setting.


Assuntos
Separação Celular/instrumentação , Separação Celular/métodos , Neoplasias Pulmonares/patologia , Técnicas Analíticas Microfluídicas/instrumentação , Células Neoplásicas Circulantes/patologia , Análise de Célula Única/instrumentação , Análise de Célula Única/métodos , Linhagem Celular Tumoral , Humanos
20.
Talanta ; 200: 177-185, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036171

RESUMO

Paper based assays are paving the way to automated, simplified, robust and cost-effective point of care testing (POCT). We propose a method for fabricating three dimensional (3D) microfluidic paper based analytical devices (µPADs) via combining thin adhesive films and paper folding, which avoids the use of cellulose powders and the complex folding sequence and simultaneously permits assays in several layers. To demonstrate the effectiveness of this approach, a 3DµPADs was designed to conduct more assays on a small footprint, allowing dual colorimetric and electrochemical detections. More importantly, we further developed a 3D platform for implementing automated and multiplexed ELISA in parallel, since ELISA, a routine and standard laboratory method, has rarely been used in practical analyses outside of the laboratory. In this configuration, complex and multistep diagnostic assays can be carried out with the addition of the sample and buffer in a simple fashion. Using Troponin I as model, the device showed a broad dynamic range of detection with a detection limit of 0.35 ng/mL. Thus, the developed platforms allow for various assays to be cost-effectively carried out on a single 3D device, showing great potential in an academic setting and point of care testing under resource-poor conditions.


Assuntos
Automação , Papel , Troponina I/análise , Colorimetria/economia , Colorimetria/instrumentação , Técnicas Eletroquímicas/economia , Técnicas Eletroquímicas/instrumentação , Técnicas Analíticas Microfluídicas/economia , Técnicas Analíticas Microfluídicas/instrumentação
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