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microfluidic chip

Mayte Conejero-Muriel, Isaac Rodriguez-Ruiz, Cristobal Verdugo-Escamilla, Andreu Llobera, Jose Antonio Gavira
Microfluidics or lab-on-a-chip technology offer clear advantages over conventional systems such as a dramatic reduction of reagent consumption or a shorter analysis time, which are translated into costs effective systems. In this work, we present a photonic enzymatic lab on a chip reactor based on Cross-Linked Enzyme Crystals (CLECs), able to work in continuous flow, as a highly sensitive, robust, reusable and stable platform for continuous sensing with superior performance as compared to the state of the art...
October 26, 2016: Analytical Chemistry
Qianghua Quan, Shuwen Zhang, Xudong Wang, Qi Ouyang, Yugang Wang, Gen Yang, Chunxiong Luo
Cell migration assays for different chemical environments are important for both scientists and clinicians searching for new therapeutics. In this study, we developed a multi-well-based microfluidic chip that has multiple units for different conditions. In each unit, cells can be patterned and then released to observe their migration. Automatic image analysis and model-based data processing were developed to describe the integrated cell migration assay precisely and quickly. As a demonstration, the migration behaviors of two types of cells in eight chemical conditions were studied...
December 2016: Biomedical Microdevices
Richard Gondosiswanto, Christian A Gunawan, David Brynn Hibbert, Jason Brian Harper, Chuan Zhao
Solvent volatility represents one of the major hurdles to the reliability and reproducibility of the lab-on-a-chip systems for large scale applications. Here we demonstrate a strategy of combining non-volatile and functionalized ionic liquids with microcontact printing for fabrication of "wall-less" microreactors with high reproducibility and high throughput. A range of thiol-functionalized ionic liquids have been synthesized and used as inks for microcontact printing of ionic liquid microdroplets arrays onto gold chips...
October 26, 2016: ACS Applied Materials & Interfaces
Yoonjee C Park, Chentian Zhang, Sudong Kim, Graciela Mohamedi, Carl Beigie, Jon O Nagy, R Glynn Holt, Robin O Cleveland, Noo Li Jeon, Joyce Y Wong
Microbubbles have been used in ultrasound-assisted drug delivery to help target solid tumors via blood vessels in vivo; however, studies to understand the phenomena at the cellular level and to optimize parameters for ultrasound or microbubbles in vivo are challenging and expensive to perform. Here, we utilize microfluidic microvessels-on-a-chip that enable visualization of microbubble/ultrasound-dependent drug delivery to microvasculature. When exposed to pulsed ultrasound, microbubbles perfused through microvessels-on-a-chip were observed to stably oscillate...
October 26, 2016: ACS Applied Materials & Interfaces
Yiwen Ouyang, Jingyi Li, Doris M Haverstick, James P Landers
We recently defined a magnetic bead-based assay that exploited an agglutination-like response for DNA and applied it to DNA-containing cell enumeration using inexpensive benchtop hardware [ J. Am. Chem. Soc. 2012 , 134 ( 12 ), 5689 - 96 ]. Although cost-efficient, the open-well format assay required numerous manual steps, and the magnetic field actuation scheme was not readily adaptable for integration. Here, we demonstrate a low-cost (<$2 in-lab), higher-throughput "pinwheel assay" platform that relies on a combination of a disposable rotation-driven microdisc (RDM), and a simple bidirectional rotating magnetic field (bi-RMF)...
October 25, 2016: Analytical Chemistry
Zitian Chen, Yusi Fu, Fangli Zhang, Lu Liu, Naiqing Zhang, Dong Zhou, Junrui Yang, Yuhong Pang, Yanyi Huang
Many on-chip approaches that use flow-focusing to pinch the continuous aqueous phase into droplets have become the most popular methods that provide monodisperse emulsion droplets. However, not every lab can easily adapt a microfluidic workflow into their familiar protocols. We develop an off-chip approach, spinning micro-pipette liquid emulsion (SiMPLE) generator, to produce highly stable monodisperse water-in-oil emulsions using a moving micropipette to disperse the aqueous phase in an oil-filled microcentrifuge tube...
October 24, 2016: Lab on a Chip
Kyung Suk Lee, Lucy E Lee, Erel Levine
Small animals such as the roundworm C. elegans are excellent models for studying bacterial infection and host response, as well as for genetic and chemical screens. A key methodology is the killing assay, in which the number of surviving animals is tracked as a function of the time post infection. This is a labor-intensive procedure, prone to human error and subjective choices, and often involves undesired perturbation to the animals and their environment. In addition, the survival of animals is just one aspect of a multi-dimensional complex biological process...
October 24, 2016: Scientific Reports
Hui Dong, Hao Sun, Jianping Zheng
With the development of large-scale biologic databases, precision medicine is becoming a frontier in biomedical research. As a main focus of precision medicine study, cancer has been widely accepted as a disease born out of inherited genetic variations or accumulating genomic damage. At the single-cell level, microfluidics or lab-on-a-chip technology for cancer study is an emerging tool for improving risk assessment, diagnostic categories and therapeutic strategies. This work presents a multi-layer microchip for single-cell gene expression profiling...
December 1, 2016: Talanta
Natta Wiriyakun, Duangjai Nacapricha, Rattikan Chantiwas
This work presents a simple hot embossing method with a shrinking procedure to produce cross-shape microchannels on poly(methyl methacrylate) (PMMA) substrate for the fabrication of an electrophoresis chip. The proposed method employed a simple two-step hot embossing technique, carried out consecutively on the same piece of substrate to make the crossing channels. Studies of embossing conditions, i.e. temperature, pressure and time, were carried out to investigate their effects on the dimension of the microchannels...
December 1, 2016: Talanta
Arvind Y M Sundaram, Timothy Hughes, Shea Biondi, Nathalie Bolduc, Sarah K Bowman, Andrew Camilli, Yap C Chew, Catherine Couture, Andrew Farmer, John P Jerome, David W Lazinski, Andrew McUsic, Xu Peng, Kamran Shazand, Feng Xu, Robert Lyle, Gregor D Gilfillan
BACKGROUND: ChIP-seq is the primary technique used to investigate genome-wide protein-DNA interactions. As part of this procedure, immunoprecipitated DNA must undergo "library preparation" to enable subsequent high-throughput sequencing. To facilitate the analysis of biopsy samples and rare cell populations, there has been a recent proliferation of methods allowing sequencing library preparation from low-input DNA amounts. However, little information exists on the relative merits, performance, comparability and biases inherent to these procedures...
October 21, 2016: BMC Genomics
Thitaphat Ngernsutivorakul, Cynthia M Cipolla, Colleen E Dugan, Shi Jin, Michael D Morris, Robert T Kennedy, Francis W L Esmonde-White
Fiber optics coupled to components such as lenses and mirrors have seen extensive use as probes for Raman and fluorescence measurements. Probes can be placed directly on or into a sample to allow for simplified and remote application of these optical techniques. The size and complexity of such probes however limits their application. We have used microfabrication in polydimethylsiloxane (PDMS) to create compact probes that are 0.5 mm thick by 1 mm wide. The miniature probes incorporate pre-aligned mirrors, lenses, and two fiber optic guides to allow separate input and output optical paths suitable for Raman and fluorescence spectroscopy measurements...
October 20, 2016: Analytical and Bioanalytical Chemistry
Yujing Li, Xueqin Huang, Robert J Lee, Yuhang Qi, Kaikai Wang, Fei Hao, Yu Zhang, Jiahui Lu, Qingfan Meng, Shuai Li, Jing Xie, Lesheng Teng
Polyethylenimine (PEI) as a cationic polymer is commonly used as a carrier for gene delivery. PEI-800 is less toxic than PEI-25K but it is also less efficient. A novel nanocarrier was developed by combining PEI-800 with a pH-sensitive lipid to form polymer-lipid hybrid nanoparticles (P/LNPs). They were synthesized by microfluidic focusing (MF). Two microfluidic devices were used to synthesize P/LNPs loaded with VEGF siRNA. A series of P/LNPs with different particle sizes and distributions were obtained by altering the flow rate and geometry of microfluidic chips, and introducing sonication...
October 17, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Chuanguang Yao, Hongxin Song, Ying Wan, Kefeng Ma, Chenyu Zheng, Hongda Cui, Peng Xin, Xubo Ji, Sheng-Yuan Deng
A porphyrin-based electro-photodynamic imaging system was fabricated for monitoring the concentration of oxygen. Distinct from the electrochemiluminescent (ECL) inability of numerous organic species in aqueous solutions, a strong and stable red irradiation at 634 nm could be stimulated electrochemically on zinc(II) meso-tetra(4-carboxyphenyl) porphine (ZnTCPP)/tetraoctylammonium bromide (TOAB) in the physiological condition. In terms of in situ electron paramagnetic resonance and ECL spectroscopies, the nature of ECL was thoroughly investigated, being exactly the chemiluminescence from singlet oxygen (1O2) produced during the successive electro-reduction of ZnTCPP...
October 20, 2016: ACS Applied Materials & Interfaces
Colleen E Dugan, James P Grinias, Sebastian D Parlee, Mahmoud El-Azzouny, Charles R Evans, Robert T Kennedy
Microfluidics is an enabling technology for both cell biology and chemical analysis. We combine these attributes with a microfluidic device for on-line solid-phase extraction (SPE) and mass spectrometry (MS) analysis of secreted metabolites from living cells in culture on the chip. The device was constructed with polydimethylsiloxane (PDMS) and contains a reversibly sealed chamber for perfusing cells. A multilayer design allowed a series of valves to control an on-chip 7.5 μL injection loop downstream of the cell chamber with operation similar to a six-port valve...
October 19, 2016: Analytical and Bioanalytical Chemistry
C S Ball, R F Renzi, A Priye, R J Meagher
Check valves are often essential components in microfluidic devices, enabling automated sample processing for diagnostics at the point of care. However, there is an unmet need for a check valve design that is compatible with rigid thermoplastic devices during all stages of development-from initial prototyping with a laser cutter to final production with injection molding. Here, we present simple designs for a passive, normally closed check valve that is manufactured from commonly available materials with a CO2 laser and readily integrated into prototype and production thermoplastic devices...
October 20, 2016: Lab on a Chip
D Caballero, J Katuri, J Samitier, S Sánchez
The ubiquitous random motion of mesoscopic active particles, such as cells, can be "rectified" or directed by embedding the particles in systems containing local and periodic asymmetric cues. Incorporated on lab-on-a-chip devices, these microratchet-like structures can be used to self-propel fluids, transport particles, and direct cell motion in the absence of external power sources. In this Focus article we discuss recent advances in the use of ratchet-like geometries in microfluidics which could open new avenues in biomedicine for applications in diagnosis, cancer biology, and bioengineering...
October 19, 2016: Lab on a Chip
Luis F Lastras-Martínez, Raul E Balderas-Navarro, Ricardo Castro-García, Karen Hernández-Vidales, Juan Almendarez-Rodríguez, Rafael Herrera-Jasso, Adrian Prinz, Iris Bergmair
The structural characterization of capillary microfluidic chips is important for reliable applications. In particular, nondestructive diagnostic tools to assess geometrical dimensions and their correlations with control processes are of much importance, preferably if they are implemented in situ. Several techniques to accomplish this task have been reported; namely, optical coherence tomography (OCT) jointly with confocal fluorescence microscopy (CFM) to investigate internal features of lab-on-a-chip technologies...
October 18, 2016: Applied Spectroscopy
Cui Hongzhou, Guo Shuping, Wang Wenju, Li Li, Wei Lulu, Deng Linjun, Li Jingmin, Ren Xiaoli, Bai Li
In recent years, molecular biology has proven to be a great asset in our understanding of mechanisms in genodermatoses. However, bench to bedside translation research lags far behind. Advances in lab-on-a-chip technologies enabled programmable, reconfigurable, and scalable manipulation of a variety of laboratory procedures. Sample preparation, microfluidic reactions, and continuous monitoring systems can be integrated on a small chip. These advantages have attracted attention in various fields of clinical application including diagnosis of inherited skin diseases...
September 13, 2016: Journal of Dermatological Science
Bugra Ayan, Adem Ozcelik, Hunter Bachman, Shi-Yang Tang, Yuliang Xie, Mengxi Wu, Peng Li, Tony Jun Huang
On-chip microparticle and cell coating technologies enable a myriad of applications in chemistry, engineering, and medicine. Current microfluidic coating technologies often rely on magnetic labeling and concurrent deflection of particles across laminar streams of chemicals. Herein, we introduce an acoustofluidic approach for microparticle and cell coating by implementing tilted-angle standing surface acoustic waves (taSSAWs) into microchannels with multiple inlets. The primary acoustic radiation force generated by the taSSAW field was exploited in order to migrate the particles across the microchannel through multiple laminar streams, which contained the buffer and coating chemicals...
October 18, 2016: Lab on a Chip
Janis C Weeks, William M Roberts, Kristin J Robinson, Melissa Keaney, Jon J Vermeire, Joseph F Urban, Shawn R Lockery, John M Hawdon
The screening of candidate compounds and natural products for anthelmintic activity is important for discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device ('chip') that records non-invasively the tiny electrophysiological signals generated by rhythmic contraction (pumping) of the worm's pharynx. These electropharyngeograms (EPGs) are recorded simultaneously from multiple worms per chip, providing a medium-throughput readout of muscular and neural activity that is especially useful for compounds targeting neurotransmitter receptors and ion channels...
September 15, 2016: International Journal for Parasitology, Drugs and Drug Resistance
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