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Lab on a Chip

Junge Chen, Youchun Xu, He Yan, Yunzeng Zhu, Lei Wang, Yan Zhang, Ying Lu, Wanli Xing
Bacterial infections may cause severe diseases such as tuberculosis, sepsis, nephritis and cystitis. The rapid and sensitive detection of bacteria is a prerequisite for the treatment of these diseases. The current gold standard for bacterial identification is bacteriological culture. However, culture-based identification takes 3-7 days, which is time-consuming and laborious. In this study, bacteria in urine samples were enriched using a portable filter-based pipette. Then, a centrifugal chip was constructed to detect multiple pathogenic bacteria from urine samples by integrating the DNA extraction, multiplex recombinase polymerase amplification (RPA) and fluorescent detection together...
July 17, 2018: Lab on a Chip
Yuxin Mao, Yang Pan, Xuan Li, Baoqing Li, Jiaru Chu, Tingrui Pan
Emerging demands for handling minute liquid samples and reagents have been constantly growing in a wide variety of medical and biological areas. This calls for low-volume and high-precision liquid handling solutions with ease-of-use and portability. In this article, a new digital droplet pipetting method is introduced for the first time, derived from the microfluidic impact printing principle. Configured as a conventional handheld pipette, the prototype device consists of a plug-and-play and disposable microfluidic pipetting chip, driven by a programmable electromagnetic actuator for on-demand dispensing of nanoliter droplets...
July 17, 2018: Lab on a Chip
Ayokunle Olanrewaju, Maïwenn Beaugrand, Mohamed Yafia, David Juncker
Microfluidics offer economy of reagents, rapid liquid delivery, and potential for automation of many reactions, but often require peripheral equipment for flow control. Capillary microfluidics can deliver liquids in a pre-programmed manner without peripheral equipment by exploiting surface tension effects encoded by the geometry and surface chemistry of a microchannel. Here, we review the history and progress of microchannel-based capillary microfluidics spanning over three decades. To both reflect recent experimental and conceptual progress, and distinguish from paper-based capillary microfluidics, we adopt the more recent terminology of capillaric circuits (CCs)...
July 16, 2018: Lab on a Chip
Younggyun Lee, Jin Woo Choi, James Yu, Dohyun Park, Jungmin Ha, Kyungmin Son, Somin Lee, Minhwan Chung, Ho-Young Kim, Noo Li Jeon
Polydimethylsiloxane (PDMS) has been widely used in fabricating microfluidic devices for prototyping and proof-of-concept experiments. Due to several material limitations, PDMS has not been widely adopted for commercial applications that require large-scale production. This paper describes a novel injection-molded plastic array 3D culture (IMPACT) platform that incorporates a microfluidic design to integrate patterned 3D cell cultures within a single 96-well (diameter = 9 mm) plate. Cell containing gels can be sequentially patterned by capillary-guided flow along the corner and narrow gaps designed within the 96-well form factor...
July 12, 2018: Lab on a Chip
Augusto M Tentori, Maxwell B Nagarajan, Jae Jung Kim, Wen Cai Zhang, Frank J Slack, Patrick S Doyle
MicroRNAs (miRNAs) have recently emerged as promising biomarkers for the profiling of diseases. Translation of miRNA biomarkers to clinical practice, however, remains a challenge due to the lack of analysis platforms for sensitive, quantitative, and multiplex miRNA assays that have simple and robust workflows suitable for translation. The platform we present here utilizes functionalized hydrogel posts contained within isolated nanoliter well reactors for quantitative and multiplex assays directly from unprocessed cell samples without the need of prior nucleic acid extraction...
July 12, 2018: Lab on a Chip
Avner Ehrlich, Sabina Tsytkin-Kirschenzweig, Konstantinos Ioannidis, Muneef Ayyash, Anne Riu, Reine Note, Gladys Ouedraogo, Jan Vanfleteren, Merav Cohen, Yaakov Nahmias
Drug development is currently hampered by the inability of animal experiments to accurately predict human response. While emerging organ on chip technology offers to reduce risk using microfluidic models of human tissues, the technology still mostly relies on end-point assays and biomarker measurements to assess tissue damage resulting in limited mechanistic information and difficulties to detect adverse effects occurring below the threshold of cellular damage. Here we present a sensor-integrated liver on chip array in which oxygen is monitored using two-frequency phase modulation of tissue-embedded microprobes, while glucose, lactate and temperature are measured in real time using microfluidic electrochemical sensors...
July 11, 2018: Lab on a Chip
Hugo Sinha, Angela B V Quach, Philippe Q N Vo, Steve C C Shih
Gene-editing techniques such as RNA-guided endonuclease systems are becoming increasingly popular for phenotypic screening. Such screens are normally conducted in arrayed or pooled formats. There has been considerable interest in recent years to find new technological methods for conducting these gene-editing assays. We report here the first digital microfluidic method that can automate arrayed gene-editing in mammalian cells. Specifically, this method was useful in culturing lung cancer cells for up to six days, as well as implementing automated gene transfection and knockout procedures...
July 10, 2018: Lab on a Chip
Maral P S Mousavi, Alar Ainla, Edward K W Tan, Mohamed K Abd El-Rahman, Yumi Yoshida, Li Yuan, Haakon H Sigurslid, Nooralhuda Arkan, Mighten C Yip, Christoffer K Abrahamsson, Shervanthi Homer-Vanniasinkam, George M Whitesides
Potentiometric sensing of ions with ion-selective electrodes (ISEs) is a powerful technique for selective and sensitive measurement of ions in complex matrices. The application of ISEs is generally limited to laboratory settings, because most commercially available ISEs and reference electrodes are large, delicate, and expensive, and are not suitable for point-of-use or point-of-care measurements. This work utilizes cotton thread as a substrate for fabrication of robust and miniaturized ISEs that are suitable for point-of-care or point-of-use applications...
July 10, 2018: Lab on a Chip
Bonhye Koo, Allison M Yorita, Jacob J Schmidt, Harold G Monbouquette
A nucleic acid amplification-free, optics-free platform has been demonstrated for sequence-specific detection of Escherichia coli (E. coli) 16S rRNA at 1 aM (10-18 M) against a 106-fold (1 pM) background of Pseudomonas putida (P. putida) RNA. This work was driven by the need for simple, rapid, and low cost means for species-specific bacterial detection at low concentration. Our simple, conductometric sensing device functioned by detecting blockage of a nanopore fabricated in a sub-micron-thick glass membrane...
July 10, 2018: Lab on a Chip
Krishna N Badhiwala, Daniel L Gonzales, Daniel G Vercosa, Benjamin W Avants, Jacob T Robinson
The nervous system of the cnidarian Hydra vulgaris exhibits remarkable regenerative abilities. When cut in two, the bisected tissue reorganizes into fully behaving animals in approximately 48 hours. Furthermore, new animals can reform from aggregates of dissociated cells. Understanding how behaviors are coordinated by this highly plastic nervous system could reveal basic principles of neural circuit dynamics underlying behaviors. However, Hydra's deformable and contractile body makes it difficult to manipulate the local environment while recording neural activity...
July 10, 2018: Lab on a Chip
Cong Wang, Keon Ah Lee, Eunpyo Choi, Keun-Young Lee, Seung-Yop Lee, Kwang-Hwan Jung, Jungyul Park
In this study, a new strategy for improving the radionuclide bio-decontamination (RBD) activity of microalgae by screening a better strain with high potential for biomineral production has been proposed. A noninvasive dielectrophoresis (DEP)-based microalgae screening microplatform has been used to select the highly capable microalgae in RBD. Microalgae (Chlorella vulgaris KMMCC9) with a high degree of competence in strontium (Sr) removal were successfully segregated against Chlorella vulgaris KCTC AG10002 that has relatively weak Sr removal activity under an AC electric field...
July 6, 2018: Lab on a Chip
Tina Tronser, Konstantin Demir, Markus Reischl, Martin Bastmeyer, Pavel A Levkin
Stem cells are influenced by various factors present in their in vivo microenvironment, such as interactions with neighboring cells, the extracellular matrix or soluble molecules. This demonstrates the high complexity of the in vivo microenvironment. Hence, many advances have been made in developing 3D screening models mimicking this complexity and the in vivo-like state in order to ensure more biomedically relevant investigations in drug discovery. In the field of stem cell research embryoid bodies are often used as relevant 3D systems...
July 6, 2018: Lab on a Chip
Kosuke Ino, Tomoaki Matsumoto, Noriko Taira, Tatsuki Kumagai, Yuji Nashimoto, Hitoshi Shiku
Bipolar electrochemistry has attracted great interest for applications based on sensing, electrografting, and electrodeposition, because the technique enables electrochemical reactions to be induced at multiple bipolar electrodes (BPEs) with only a single power supply. However, there are only a few reports on the biofabrication of hydrogels using BPEs. In this study, we applied bipolar electrochemistry to achieve the electrodeposition of calcium-alginate hydrogels at specified target areas, which is possible because of the use of water electrolysis to obtain acidification at the anodic pole...
July 6, 2018: Lab on a Chip
Line Hagner Nielsen, Stephan Sylvest Keller, Anja Boisen
Oral administration of drugs is most convenient for patients and therefore the ultimate goal when developing new medication. The physical barriers in the body, low pH of the stomach and degradation by enzymes in the gastrointestinal tract are a few of the obstacles to succeeding with oral drug delivery. Microfabricated devices show promise to overcome some of these hindrances and thereby improve the bioavailability of drugs after oral administration. There is an increasing focus on microfabricated oral drug delivery systems, and so far there have been three main groups of designs: patch-like structures, microcontainers and microwells...
July 5, 2018: Lab on a Chip
Yurina Sekine, Sung Bong Kim, Yi Zhang, Amay J Bandodkar, Shuai Xu, Jungil Choi, Masahiro Irie, Tyler R Ray, Punit Kohli, Naofumi Kozai, Tsuyoshi Sugita, Yixin Wu, KunHyuck Lee, Kyu-Tae Lee, Roozbeh Ghaffari, John A Rogers
The rich composition of solutes and metabolites in sweat and its relative ease of collection upon excretion from skin pores make this class of biofluid an attractive candidate for point of care analysis. Wearable technologies that combine electrochemical sensors with conventional or emerging semiconductor device technologies offer valuable capabilities in sweat sensing, but they are limited to assays that support amperometric, potentiometric, and colorimetric analyses. Here, we present a complementary approach that exploits fluorometric sensing modalities integrated into a soft, skin-interfaced microfluidic system which, when paired with a simple smartphone-based imaging module, allows for in situ measurement of important biomarkers in sweat...
June 29, 2018: Lab on a Chip
Zhong Ren, Medine Ayhan, Sepalika Bandara, Kalinga Bowatte, Indika Kumarapperuma, Semini Gunawardana, Heewhan Shin, Cong Wang, Xiaoli Zeng, Xiaojing Yang
Recent developments in serial crystallography at X-ray free electron lasers (XFELs) and synchrotrons have been driven by two scientific goals in structural biology - first, static structure determination from nano or microcrystals of membrane proteins and large complexes that are difficult for conventional cryocrystallography, and second, direct observations of transient structural species in biochemical reactions at near atomic resolution. Since room-temperature diffraction experiments naturally demand a large quantity of purified protein, sample economy is critically important for all steps of serial crystallography from crystallization, crystal delivery to data collection...
June 28, 2018: Lab on a Chip
Eddie Hofmann, Kilian Krüger, Christian Haynl, Thomas Scheibel, Martin Trebbin, Stephan Förster
We present a microfluidic nozzle device for the controlled continuous solution blow spinning of ultrafine fibers. The device is fabricated by soft lithography techniques and is based on the principle of a gas dynamic virtual nozzle for precise three-dimensional gas focusing of the spinning solution. Uniform fibers with virtually endless length can be produced in a continuous process while having accurate control over the fiber diameter. The nozzle device is used to produce ultrafine fibers of perfluorinated copolymers and of polycaprolactone, which are collected and drawn on a rotating cylinder...
June 27, 2018: Lab on a Chip
E Simone, J McVeigh, N M Reis, Z K Nagy
In this work, a novel multi-microfluidic crystallization platform called MMicroCryGen is presented, offering a facile methodology for generating individual crystals for fast and easy screening of the polymorphism and crystal habit of solid compounds. The MMicroCryGen device is capable of performing 8 × 10 cooling crystallization experiments in parallel using 8 disposable microcapillary film strips, each requiring less than 25 μL of solution. Compared to traditional microfluidic systems, the MMicroCryGen platform does not require complex fluid handling; it can be directly integrated with a 96-well microplate and it can also work in a "dipstick" mode...
June 27, 2018: Lab on a Chip
Liang Huang, Peng Zhao, Wenhui Wang
3D rotation is one of many fundamental manipulations to cells and imperative in a wide range of applications in single cell analysis involving biology, chemistry, physics and medicine. In this article, we report a dielectrophoresis-based, on-chip manipulation method that can load and rotate a single cell for 3D cell imaging and multiple biophysical property measurements. To achieve this, we trapped a single cell in constriction and subsequently released it to a rotation chamber formed by four sidewall electrodes and one transparent bottom electrode...
June 27, 2018: Lab on a Chip
Raehyun Kim, Yuli Wang, Shee-Hwan J Hwang, Peter J Attayek, Nicole M Smiddy, Mark I Reed, Christopher E Sims, Nancy L Allbritton
A simple, in vitro intestinal model recapitulating key aspects of crypt architecture and physiology would facilitate our understanding the impact of drugs, foods and microbial metabolites on the intestine. To address the limitations of previously reported intestinal in vitro platforms, we developed a planar crypt array that replicated the spatial segregation and physiologic responses of primary mouse intestinal epithelial cells in the large intestine. Collagen was coated across an impermeable film possessing an array of microholes creating two regions of distinct stiffness and porosity (above and outside the microholes)...
June 26, 2018: Lab on a Chip
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