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1.
Adv Exp Med Biol ; 1146: 79-103, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31612455

RESUMO

The last 20 years have seen the blooming of microfluidics technologies applied to biological sciences. Microfluidics provides effective tools for biological analysis, allowing the experimentalists to extend their playground to single cells and single molecules, with high throughput and resolution which were inconceivable few decades ago. In particular, microfluidic devices are profoundly changing the conventional way of studying the cell motility and cell migratory dynamics. In this chapter we will furnish a comprehensive view of the advancements made in the research domain of confinement-induced cell migration, thanks to the use of microfluidic devices. The chapter is subdivided in three parts. Each section will be addressing one of the fundamental questions that the microfluidic technology is contributing to unravel: (i) where cell migration takes place, (ii) why cells migrate and, (iii) how the cells migrate. The first introductory part is devoted to a thumbnail, and partially historical, description of microfluidics and its impact in biological sciences. Stress will be put on two aspects of the devices fabrication process, which are crucial for biological applications: materials used and coating methods. The second paragraph concerns the cell migration induced by environmental cues: chemical, leading to chemotaxis, mechanical, at the basis of mechanotaxis, and electrical, which induces electrotaxis. Each of them will be addressed separately, highlighting the fundamental role of microfluidics in providing the well-controlled experimental conditions where cell migration can be induced, investigated and ultimately understood. The third part of the chapter is entirely dedicated to how the cells move in confined environments. Invadosomes (the joint name for podosomes and invadopodia) are cell protrusion that contribute actively to cell migration or invasion. The formation of invadosomes under confinement is a research topic that only recently has caught the attention of the scientific community: microfluidic design is helping shaping the future direction of this emerging field of research.


Assuntos
Movimento Celular , Microfluídica , Podossomos , Animais , Quimiotaxia , Humanos , Dispositivos Lab-On-A-Chip , Microfluídica/instrumentação , Podossomos/metabolismo , Pesquisa/tendências
2.
Anal Bioanal Chem ; 411(23): 6119-6128, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31388714

RESUMO

A new approach employing a microchip in combination with photothermal lens microscopy has been described for a DNA hybridization assay using gold nanoparticles. The difference in adsorption propensities of single- and double-stranded DNAs on gold nanoparticles was used for a highly sensitive DNA hybridization assay through a photothermal lens effect in a femtoliter scale of detection volume. Under the optimized conditions, the results showed that the variation of photothermal lens signal in the focal volume of 105 fL (10-15 L) was linearly proportional to the target DNA concentration over the range of 50-500 nM with detection limits of 30.7 nM and 27.3 nM for target DNA I and II, respectively. The lowest amount of target DNA that was measured using gold nanoparticles was 2.6 zepto mole. The assay was completed within 5 min and the relative standard deviations (n = 8) for both target DNAs were about 2.34%. The hybridization process was proved by two different common methods including gel electrophoresis and in situ fluorescence monitoring of DNA hybridization. The performance of this detection method was investigated in diluted human serum sample as a complex sample. The recovery values were between 98 and 104.9%. Graphical abstract.


Assuntos
DNA/análise , Ouro/química , Dispositivos Lab-On-A-Chip , Nanopartículas Metálicas/química , Hibridização de Ácido Nucleico , Técnicas Biossensoriais/instrumentação , DNA/genética , Desenho de Equipamento , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Microscopia/instrumentação
3.
Int J Nanomedicine ; 14: 4187-4209, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31289440

RESUMO

Circulating tumor cells (CTCs) are disseminated cancer cells. The occurrence and circulation of CTCs seem key for metastasis, still the major cause of cancer-associated deaths. As such, CTCs are investigated as predictive biomarkers. However, due to their rarity and heterogeneous biology, CTCs' practical use has not made it into the clinical routine. Clearly, methods for the effective isolation and reliable detection of CTCs are urgently needed. With the development of nanotechnology, various nanosystems for CTC isolation and enrichment and CTC-targeted cancer therapy have been designed. Here, we summarize the relationship between CTCs and tumor metastasis, and describe CTCs' unique properties hampering their effective enrichment. We comment on nanotechnology-based systems for CTC isolation and recent achievements in microfluidics and lab-on-a-chip technologies. We discuss recent advances in CTC-targeted cancer therapy exploiting the unique properties of nanomaterials. We conclude by introducing developments in CTC-directed nanosystems and other advanced technologies currently in (pre)clinical research.


Assuntos
Biomarcadores Tumorais/análise , Separação Celular/métodos , Nanomedicina/métodos , Células Neoplásicas Circulantes/patologia , Biomarcadores Tumorais/isolamento & purificação , Materiais Biomiméticos , Grafite , Humanos , Dispositivos Lab-On-A-Chip , Microfluídica/instrumentação , Microfluídica/métodos , Nanoestruturas/química , Nanotecnologia/métodos , Nanotubos de Carbono
4.
Expert Opin Drug Saf ; 18(8): 651-677, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31268355

RESUMO

INTRODUCTION: Historically, drug development and marketing failures have been experienced by pharma organizations largely from insufficient human-predictability of biological data. AREAS COVERED: Organs-on-chips (OOCs) are emerging, cutting edge microphysiology systems for in vitro production of microengineered three-dimensional, miniature organotypic constructs obtained by cultivating small amounts of human primary, or induced pluripotent stem, cells in native-like microhabitats. These preparations circumvent experimental limitations inherent to animal assays and two-dimensional monolayers, the mainstay core biological assays of traditional drug research. This report reviews the fundamental tenets, key components (chip plate, biomaterials, cell differentiation approaches, and monitoring sensors) and issues concerning OOC systems (engineered top-down and bottom-up strategies for tissue/organ assembly, public aids to OOC development, regulatory validation, advantages, limitations, prospective and perspective of OOCs, ethics). Examples of OOC platforms (cancer-, lung-, blood-brain barrier-, heart-, intestine-, kidney-, liver-, pharmacokinetics-, placenta and vessel-on-chip) and their importance for drug research and development are presented. EXPERT OPINION: OOC device-generated bioconstructs hold great promise as experimental human tissue and organ platforms for generating human-pertinent knowledge on drug candidates for clinical assessment and reducing reliance on animal models. MPS technologies currently enable ready-to-assemble tissue patches and, hopefully, in coming decades, full-size, patient-personalized organs for regenerative medical interventions.


Assuntos
Desenvolvimento de Medicamentos/métodos , Dispositivos Lab-On-A-Chip , Modelos Biológicos , Alternativas aos Testes com Animais , Animais , Humanos , Pesquisa Farmacêutica/métodos , Células-Tronco/citologia
5.
Yi Chuan ; 41(7): 611-624, 2019 Jul 20.
Artigo em Chinês | MEDLINE | ID: mdl-31307970

RESUMO

Rapid detection of pathogenic microorganisms is key to the epidemiologic identification, prevention and control of disease in the field of public health. PCR-based pathogen detection methods have been widely used because they overcome the time-consuming issues that traditional culture-based methods required including the limited window required by immunological detection. However, the requirement on precision temperature-controlled thermal cyclers severely limits their use in resource-limited areas. The detection methods of pathogenic microorganisms based on isothermal amplification of nucleic acids are free of dependence on high-precision temperature control equipment, but requirements for nucleic acids extraction, amplification and detection must be defined. In recent years, a number of alternative methods for pathogenic microorganism detection have been developed by combining microfluidic technology with nucleic acid isothermal amplification technology. By designing the chip structures, optimizing the injection modes, and utilizing multiple detection and quantitative methods, the integration of pathogen nucleic acid extraction, amplification and detection is achieved. The method provides advantages of less instrument dependence, decreased operator requirements, smaller sample size, and higher automation which are suitable for the rapid detection of pathogenic microorganisms in various environments. In this review, we summarize several microfluidic detection methods based on nucleic acid isothermal amplification for pathogens including amplification principles, injection methods and detection methods. These methods provide more capability for the rapid screening of pathogenic microorganisms which enhances the management of infectious diseases in the field of public health.


Assuntos
Bactérias/isolamento & purificação , Dispositivos Lab-On-A-Chip , Técnicas de Amplificação de Ácido Nucleico , Ácidos Nucleicos/análise , Vírus/isolamento & purificação , Bactérias/patogenicidade , Reação em Cadeia da Polimerase , Vírus/patogenicidade
6.
Eur Biophys J ; 48(6): 549-558, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31327019

RESUMO

Liposomes are spherical vesicles enclosed by phospholipid bilayers. Nanoscale liposomes are widely employed for drug delivery in the pharmaceutical industry. In this study, nanoscale liposomes are fabricated using the microfluidic hydrodynamic focusing (MHF) approach, and the effects of flow rate ratio (FRR) on liposome size and drug loading efficiency are studied. Fluorescein isothiocyanate modified dextran is used as a hydrophilic drug simulant and Nile red is used as a hydrophobic drug simulant. The experiment results show that hydrophilic drug simulant loading efficiency increases as FRR increases and eventually plateaues at around 90% loading efficiency. The hydrophobic drug simulant loading efficiency and FRR have a positive linear correlation when FRR varies from 10 to 50. Concurrent loading of both hydrophilic and hydrophobic drug simulants maintains the same loading efficiencies as those of loading each drug simulant alone. A negative correlation between liposome size and FRR is also confirmed. Unloaded liposomes and hydrophilic drug-loaded liposomes are of the same sizes, and are smaller than the ones loaded with the hydrophobic drug simulants alone or combined. The results suggest tunable liposome size and drug loading efficiency with the MHF technique. This provides evidence to encourage further studies of microfluidic liposome fabrication in the pharmaceutical industry.


Assuntos
Hidrodinâmica , Dispositivos Lab-On-A-Chip , Lipossomos/química , Preparações Farmacêuticas/química , Interações Hidrofóbicas e Hidrofílicas , Oxazinas/química
7.
Food Chem ; 297: 124930, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253279

RESUMO

A new microfluidic chemiluminescence (MF-CL) method for rapidly assaying the total antioxidant capacity (TAC) of apple and pomegranate juices and honey samples was developed. The method exploited the NaHCO3-H2O2-Co2+ CL reaction. It was found that gallic acid (GA), catechin, caffeic acid, ferulic acid and rutin, as selected phenolic antioxidants, could suppress the CL reaction. The linear range and limit of detection of the method for the antioxidants were as follows: 0.5-3 mg L-1 and 0.27 mg L-1 for GA, 0.2-5.0 mg L-1 and 0.17 mg L-1 for catechin, 0.03-2.0 mg L-1 and 0.03 mg L-1 for caffeic acid, 0.3-2.0 mg L-1 and 0.23 mg L-1 for ferulic acid and 0.3-4.0 mg L-1 and 0.15 mg L-1 for rutin. GA was used as the standard, and the TAC of the fruit juices and honey samples as presented as GA equivalents (GAE). MF-CL was compared with DPPH and Folin-Ciocalteau (FC) methods.


Assuntos
Antioxidantes/química , Sucos de Frutas e Vegetais/análise , Mel/análise , Dispositivos Lab-On-A-Chip , Medições Luminescentes/métodos , Cobalto/química , Ácido Gálico/química , Peróxido de Hidrogênio/química , Medições Luminescentes/instrumentação , Bicarbonato de Sódio/química
8.
J Chromatogr A ; 1602: 467-473, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31178161

RESUMO

The detection and analysis of explosives and explosive-related compounds is a heightened priority in recent years for homeland security and counter-terrorism applications. This study aimed to evaluate the use of a commercial Lab-On-a-Chip (LOC) instrument for the analysis of explosive vapours, with the long-term goal of developing a portable instrument for passively detecting explosives in air samples. A simple method to collect explosive vapour residues was developed using a glass vial containing varying amounts of the target explosives (1 mg/mL). Standards were diluted to the desired concentration in 150 µL of acetone to facilitate the evaporation. The top of the vial was covered with a circular 0.5 cm diameter filter paper and exposed to a range of temperatures from 22 °C to 80 °C for 15 min. Following evaporation, the filter paper chads were folded and inserted into the LOC wells containing the separation buffer for the analysis, avoiding any further extraction step. After successfully separating and detecting eight explosives via liquid analysis, three explosives were chosen as targets for the vapour analysis experiments. 1,3,5-Trinitrobenzene (TNB), 2,4,6-Trinitrotoluene (TNT), and 2,4,6-Trinitrophenylmethylnitramine (Tetryl) were successfully separated, detected and identified following the vapour extraction of explosive standards onto filter paper chads. Limits of detection for the liquid analysis were demonstrated to be 2.32 ng for TNB, 2.35 ng for Tetryl, and 3.25 ng for TNT. The minimum detectable mass found for the vapour analysis was 6.03 for TNB, 9.99 ng for TNT, and 14.22 ng for Tetryl. The average recovery from the paper chads was 29% for Tetryl, 47% for TNB, and 75% for TNT (n = 4), comparable with findings from previous studies. Results show that a minimum temperature of 40 °C is necessary to vaporize the compounds using acetone, while the best results were achieved when heating the vial to 80 °C. The use of a filter paper to collect the explosives residues, avoiding any additional extraction step, and the ability to analyze these compounds using a LOC instrument, makes this approach a future alternative method for explosive residues detection in the headspace.


Assuntos
Substâncias Explosivas/análise , Dispositivos Lab-On-A-Chip , Nitratos/análise , Limite de Detecção , Padrões de Referência , Temperatura Ambiente , Volatilização
9.
Int Arch Allergy Immunol ; 180(1): 28-36, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31189157

RESUMO

BACKGROUND: Clinically meaningful specific IgE determination is an important step in the diagnosis of allergic diseases. While patient's history and skin prick tests are available during the medical visit, most IgE immunoassays require hours to several days to be available. Recent developments in the field of nanofluidic technology open new horizons for point-of-care management of this unmet medical need. OBJECTIVE: This study aimed to compare IgE diagnostic agreement between a nanofluidic assay (abioSCOPE®) and a laboratory reference method (Phadia Laboratory System®) in a real-world clinical setting. METHODS: Sera from 105 patients whose routine allergy diagnostic workup required a blood sampling were used to compare the novel nanofluidic IgE assay to a reference method in a blind manner for a panel of five respiratory allergens. To assess the agreement between methods, patient records were reviewed by four independent experts to establish the final diagnosis. Experts were blinded to the IgE serological method used, but had access to patient history, skin prick tests, and blood test results. RESULTS: Analytic agreement between the two methods was 81% for the tested panel of allergens (ranging from 77 to 89%). The overall agreement in clinical diagnosis decision taken by the expert panel was 94.6% with the nanofluidic IgE assay when compared to the reference method. CONCLUSION: The nanofluidic IgE assay, as determined through an evaluation based on clinical history, skin prick tests, and IgE measurement, is a valuable tool for allergy experts to identify patients' sensitization patterns at the point of care, and for routine IgE diagnostic workup.


Assuntos
Imunoensaio/métodos , Imunoensaio/normas , Imunoglobulina E/imunologia , Dispositivos Lab-On-A-Chip , Nanotecnologia/métodos , Adolescente , Adulto , Idoso , Alérgenos/imunologia , Feminino , Humanos , Hipersensibilidade/diagnóstico , Hipersensibilidade/imunologia , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Testes Cutâneos , Adulto Jovem
10.
Nat Methods ; 16(7): 640-648, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31249412

RESUMO

Signaling centers, localized groups of cells that secrete morphogens, play a key role in early development and organogenesis by orchestrating spatial cell fate patterning. Here we present a microfluidic approach that exposes human pluripotent stem cell (hPSC) colonies to spatiotemporally controlled morphogen gradients generated from artificial signaling centers. In response to a localized source of bone morphogenetic protein 4 (BMP4), hPSC colonies reproducibly break their intrinsic radial symmetry to produce distinct, axially arranged differentiation domains. Counteracting sources of the BMP antagonist NOGGIN enhance this spatial control of cell fate patterning. We also show how morphogen concentration and cell density affect the BMP response and germ layer patterning. These results demonstrate that the intrinsic capacity of stem cells for self-organization can be extrinsically controlled through the use of engineered signaling centers.


Assuntos
Células-Tronco Pluripotentes/citologia , Padronização Corporal , Proteína Morfogenética Óssea 4/farmacologia , Contagem de Células , Diferenciação Celular , Humanos , Dispositivos Lab-On-A-Chip
11.
Anal Bioanal Chem ; 411(20): 5297-5307, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31161322

RESUMO

The design and fabrication of a continuous-flow µPCR device with very short amplification time and low power consumption are presented. Commercially available, 4-layer printed circuit board (PCB) substrates are employed, with in-house designed yet industrially manufactured embedded Cu micro-resistive heaters lying at very close distance from the microfluidic network, where DNA amplification takes place. The 1.9-m-long microchannel in combination with desirably high flow velocities (for fast amplification) challenged the robustness of the sealing that was overcome with the development of a novel bonding method rendering the microdevice robust even at extreme pressure drops (12 bars). The proposed fabrication methods are PCB compatible, allowing for mass and reliable production of the µPCR device in the established PCB industry. The µPCR chip was successfully validated during the amplification of two different DNA fragments (and with different target DNA copies) corresponding to the exon 20 of the BRCA1 gene, and to the plasmid pBR322, a commonly used cloning vector in E. coli. Successful DNA amplification was demonstrated at total reaction times down to 2 min, with a power consumption of 2.7 W, rendering the presented µPCR one of the fastest and lowest power-consuming devices, suitable for implementation in low-resource settings. Detailed numerical calculations of the DNA residence time distributions, within an acceptable temperature range for denaturation, annealing, and extension, performed for the first time in the literature, provide useful information regarding the actual on-chip PCR protocol and justify the maximum volumetric flow rate for successful DNA amplification. The calculations indicate that the shortest amplification time is achieved when the device is operated at its enzyme kinetic limit (i.e., extension rate). Graphical abstract.


Assuntos
DNA/química , Dispositivos Lab-On-A-Chip , Manufaturas , Bifenilos Policlorados/química , Reação em Cadeia da Polimerase/métodos
12.
Nat Commun ; 10(1): 2879, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253767

RESUMO

Drug development often relies on high-throughput cell-based screening of large compound libraries. However, the lack of miniaturized and parallelized methodologies in chemistry as well as strict separation and incompatibility of the synthesis of bioactive compounds from their biological screenings makes this process expensive and inefficient. Here, we demonstrate an on-chip platform that combines solution-based synthesis of compound libraries with high-throughput biological screenings (chemBIOS). The chemBIOS platform is compatible with both organic solvents required for the synthesis and aqueous solutions necessary for biological screenings. We use the chemBIOS platform to perform 75 parallel, three-component reactions to synthesize a library of lipidoids, followed by characterization via MALDI-MS, on-chip formation of lipoplexes, and on-chip cell screening. The entire process from the library synthesis to cell screening takes only 3 days and about 1 mL of total solutions, demonstrating the potential of the chemBIOS technology to increase efficiency and accelerate screenings and drug development.


Assuntos
Técnicas de Química Combinatória , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Células HEK293 , Humanos , Dispositivos Lab-On-A-Chip , Lipossomos , Bibliotecas de Moléculas Pequenas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
13.
Phys Chem Chem Phys ; 21(24): 13005-13013, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31165825

RESUMO

Cubosomes and hexosomes are emerging platforms for drug and nutraceutical delivery applications. In addition to common high- and low-energy batch emulsification methods for the preparation of these nano-self-assemblies, it is important to introduce suitable microfluidic devices with a precision control of the flow parameters for their continuous production. Microfluidics has several advantages including cost effectiveness, short-production time, and control of the nanoparticle size and size distribution. In the present study, a hydrodynamic flow focusing polyimide microfluidic device was employed for the continuous production of hexosomes based on docosahexaenoic acid monoglyceride (MAG-DHA), in the presence of the stabilizer Pluronic F127. The size, structural, morphological and size characterizations of the continuously produced MAG-DHA nanodispersions were investigated through an integrated approach involving synchrotron small angle X-ray scattering, dynamic light scattering, and cryogenic transmission electron microscopy. We report on a simple process for the microfluidic synthesis of hexosomes with sizes ranging from 108 to 138 nm and relatively narrow size distributions as the polydispersity indices were in the range of 0.14-0.22. At the applied total volumetric flow rates (TFRs) ranging of 50-150 µL min-1 and flow rate ratios (FRRs) of 10-30, it was evident from SAXS findings that ethanol has only a slight effect on the lattice parameter of the internal inverse hexagonal (H2) phase of the produced hexosomes. In addition to hexosomes, cryo-TEM observations indicated the coexistence of vesicular structures and smaller nano-objects. The formation of these nano-objects that are most likely normal micelles was also confirmed by SAXS, particularly on increasing FRR from 10 to 20 or 30 at TFR of 150 µL min-1. Taking into account the reported positive health effects of MAG-DHA, which is a long-chain omega-3 (ω-3) polyunsaturated fatty acid (PUFA) monoglyceride, in various disorders including cancer, the produced hexosomes are attractive for the delivery of ω-3 PUFAs, drugs, nutraceuticals, and their combinations.


Assuntos
Ácidos Docosa-Hexaenoicos/química , Ácidos Graxos Ômega-3/química , Dispositivos Lab-On-A-Chip , Nanopartículas/química , Hidrodinâmica , Micelas , Monoglicerídeos/química , Tamanho da Partícula , Poloxâmero/química
14.
Anal Chim Acta ; 1076: 110-117, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31203954

RESUMO

Encoded hydrogel microparticles, synthesized by Stop Flow Lithography (SFL), have shown great potential for microRNA assays for their capability to provide high multiplexing capacity and solution-like hybridization kinetics. However, due to the low conversion of copolymerization during particle synthesis, current hydrogel microparticles can only utilize ∼10% of the input probes that functionalize the particles for miRNA assay. Here, we present a novel method of functionalizing hydrogel microparticles after particle synthesis by utilizing unconverted double bonds remaining inside the hydrogel particles to maximize functional probe incorporation and increase the performance of miRNA assay. This allows covalent bonding of functional probes to the hydrogel network after particle synthesis. Because of the abundance of the unconverted double bonds and accessibility of all probes, the probe density increases about 8.2 times compared to that of particles functionalized during the synthesis. This results lead to an enhanced miRNA assay performance that improves the limit of detection from 4.9 amol to 1.5 amol. In addition, higher specificity and shorter assay time are achieved compared to the previous method. We also demonstrate a potential application of our particles by performing multiplexed miRNA detections in human plasma samples.


Assuntos
Hidrogéis/química , MicroRNAs/sangue , Biomarcadores/sangue , DNA/química , DNA/genética , Sondas de DNA/química , Sondas de DNA/genética , Humanos , Hidrogéis/síntese química , Dispositivos Lab-On-A-Chip , MicroRNAs/genética , Técnicas Analíticas Microfluídicas/métodos , Hibridização de Ácido Nucleico , Polietilenoglicóis/química , Porosidade
15.
Anal Chim Acta ; 1076: 118-124, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31203955

RESUMO

The quantification of low concentration proteins can facilitate the discovery of some significant biomarkers, and provide us a more profound understanding of cell heterogeneity when applied to single cell analysis. However, most state-of- art single cell protein detection platforms are bulky, expensive and complicated. Here we report a simple and low cost microfluidic dPCR (digital polymerase chain reaction) chip-based proximity ligation assay (PLA) for the quantification of low concentration proteins. First, standard hCSTB (human cystatin B) protein was used to optimize the related experimental conditions. Comparing to ordinary PLA tests, the results showed that our method achieved femtomolar limit of detection (LOD) with a linear dynamic range over three to four orders of magnitude. Then human CD147 protein, a reported biomarker for hepatoma carcinoma, was detected in single HepG2 and L02 cells. The results showed that there were wide disparities in single cell CD147 abundance for both of the two cell lines. And the average CD147 protein content in single HepG2 cells displayed 2-fold increase in comparison to that in single L02 cells. Comparing to the research findings obtained at bulk level, our method can provide more useful information for diagnosis and targeted therapy of tumors.


Assuntos
Basigina/análise , Cistatina B/análise , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/métodos , Biomarcadores Tumorais/análise , Linhagem Celular Tumoral , Humanos , Limite de Detecção , Técnicas Analíticas Microfluídicas/instrumentação , Reação em Cadeia da Polimerase/instrumentação , Reação em Cadeia da Polimerase/métodos , Análise de Célula Única/instrumentação , Análise de Célula Única/métodos
16.
Anal Chim Acta ; 1076: 154-161, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31203960

RESUMO

Cancer cell detection in liquid biopsies has been a widely studied application in many microfluidic devices. The use of a common antibody, such as the epithelial cell adhesion molecule (Anti-EpCAM) or other specific antibodies, has facilitated the detection and study of many cancers. However, the use of such antibodies requires a priori knowledge of the cancer source, and many cancer subtypes are missed in screening applications. There remains a need to study a wider range of cancers that maintain the streamlined antibody approach in cell affinity separations. The Human transferrin receptor (CD71) has recently been demonstrated as a cancer cell affinity target in blood samples. CD71 expression in blood cells is low, whereas proliferating cancer cells have a higher expression of the surface protein. CD71 expression is variable with cell cycle, which can impact cell separations. In this work, we investigated the effects of cell cycle and CD71 expression on cell capture metrics. Six cancer cell lines were isolated from blood via CD71 affinity capture, with a capture efficiency and purity that varied with CD71 expression. Despite variation in CD71 expression, the affinity was sufficient to isolate cancer cells spiked into blood; under optimal conditions, CD71-based capture resulted in capture purity >80%. We conclude that CD71 affinity separations show potential as a biomarker for cancer studies without sacrificing sensitivity and selectivity, and that cancer cells can be isolated from liquid biopsies over a range of expression of the target protein.


Assuntos
Antígenos CD/imunologia , Biomarcadores Tumorais/imunologia , Células Neoplásicas Circulantes/imunologia , Receptores da Transferrina/imunologia , Anticorpos Monoclonais/imunologia , Linhagem Celular Tumoral , Citometria de Fluxo/instrumentação , Citometria de Fluxo/métodos , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Dispositivos Lab-On-A-Chip , Ligantes , Biópsia Líquida , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos
17.
Adv Mater ; 31(32): e1902109, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31206791

RESUMO

Comprehensive analysis of sweat chemistry provides noninvasive health monitoring capabilities that complement established biophysical measurements such as heart rate, blood oxygenation, and body temperature. Recent developments in skin-integrated soft microfluidic systems address many challenges associated with standard technologies in sweat collection and analysis. However, recording of time-dependent variations in sweat composition requires bulky electronic systems and power sources, thereby constraining form factor, cost, and modes of use. Here, presented are unconventional design concepts, materials, and device operation principles that address this challenge. Flexible galvanic cells embedded within skin-interfaced microfluidics with passive valves serve as sweat-activated "stopwatches" that record temporal information associated with collection of discrete microliter volumes of sweat. The result allows for precise measurements of dynamic sweat composition fluctuations using in situ or ex situ analytical techniques. Integrated electronics based on near-field communication (NFC) protocols or docking stations equipped with standard electronic measurement tools provide means for extracting digital timing results from the stopwatches. Human subject studies of time-stamped sweat samples by in situ colorimetric methods and ex situ techniques based on inductively coupled plasma mass spectroscopy (ICP-MS) and chlorodimetry illustrate the ability to quantitatively capture time-dynamic sweat chemistry in scenarios compatible with field use.


Assuntos
Desenho de Equipamento/instrumentação , Dispositivos Lab-On-A-Chip , Pele/química , Suor/química , Técnicas Biossensoriais/instrumentação , Colorimetria , Teste de Esforço , Humanos , Smartphone , Fatores de Tempo , Dispositivos Eletrônicos Vestíveis
19.
Stud Health Technol Inform ; 261: 274-279, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156129

RESUMO

The main goal of this research is to design, develop and implement an efficient protocol to generate 3D neural cultures derived from human induced Pluripotent Stem Cells (hiPSCs) coupled to Micro Electrode Arrays (MEA) in order to obtain an engineered and controlled brain-on-a-chip model. The use of patient specific iPSCs may offer novel insights into the pathophysiology of a large variety of disorders, including numerous neurodevelopmental and late-onset neurodegenerative conditions. With these in vitro patient specific models, we may have the possibility to test drugs and find ad hoc therapies in the direction of precision medicine.


Assuntos
Encéfalo , Células-Tronco Pluripotentes Induzidas , Dispositivos Lab-On-A-Chip , Técnicas de Cultura de Órgãos , Encéfalo/fisiologia , Humanos , Doenças Neurodegenerativas , Transtornos do Neurodesenvolvimento , Organoides
20.
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
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