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Lab on a Chip

Ardon Z Shorr, Utku M Sönmez, Jonathan S Minden, Philip R LeDuc
Developing embryos create complexity by expressing genes to coordinate movement which generates mechanical force. An emerging theory is that mechanical force can also serve as an input signal to regulate developmental gene expression. Experimental methods to apply mechanical stimulation to whole embryos have been limited, mainly to aspiration, indentation, or moving a coverslip; these approaches stimulate only a few embryos at a time and require manual alignment. A powerful approach for automation is microfluidic devices, which can precisely manipulate hundreds of samples...
February 19, 2019: Lab on a Chip
Jeremy F Wong, Craig A Simmons
Cell monolayers, including endothelial cells lining the vasculature and blood-brain barrier, and epithelial cells lining the lung airways and gut, form a semipermeable barrier across which transport of biomolecules is tightly regulated. The assessment of barrier function is therefore critical in in vitro models of barrier-forming tissues, including microfluidic organ-on-a-chip models. Cell monolayer barrier function is commonly assessed using a fluorescent tracer-based permeability assay in both conventional Transwell and organ-on-a-chip models, but this method requires laborious manual sampling, bulky instrumentation and offline sample processing...
February 19, 2019: Lab on a Chip
Mohamed Elhebeary, Md Abul Bashar Emon, Onur Aydin, M Taher A Saif
We introduce a novel method to form 3D biomimetic tissues from a droplet of a cell-extracellular matrix (ECM) mixture on a sensor stage and to quantify tissue force and stiffness as a function of time under optical microscopes. This method exploits advances in micro-nano fabrication and capillarity for self-assembly and self-alignment of tissues on the stage. It allows simultaneous investigation of the microstructure of the tissue in situ while its mechanical response is quantified, thus linking tissue biophysics with physiology and revealing structural-functional properties of 3D tissues...
February 18, 2019: Lab on a Chip
Jinxin Zhang, Shujie Yang, Chuyi Chen, Jessica H Hartman, Po-Hsun Huang, Lin Wang, Zhenhua Tian, Peiran Zhang, David Faulkenberry, Joel N Meyer, Tony Jun Huang
Controllable, precise, and stable rotational manipulation of model organisms is valuable in many biomedical, bioengineering, and biophysics applications. We present an acoustofluidic chip capable of rotating Caenorhabditis elegans (C. elegans) in both static and continuous flow in a controllable manner. Rotational manipulation was achieved by exposing C. elegans to a surface acoustic wave (SAW) field that generated a vortex distribution inside a microchannel. By selectively activating interdigital transducers, we achieved bidirectional rotation of C...
February 15, 2019: Lab on a Chip
Miguel Solsona, Eiko Y Westerbeek, Johan G Bomer, Wouter Olthuis, Albert van den Berg
In this work, a new method to track particles in microfluidic channels is presented. Particle position tracking in microfluidic systems is crucial to characterize sorting systems or to improve the analysis of cells in impedance flow cytometry studies. By developing an electric field gradient in a two parallel electrode array the position of the particles can be tracked in one axis by impedance analysis. This method can track the particle's position at lower frequencies and measure the conductivity of the system at higher frequencies...
February 15, 2019: Lab on a Chip
Seunggyu Kim, Fahim Masum, Ju-Kang Kim, Hyun Jung Chung, Jessie S Jeon
Combinatory therapy using two or more kinds of antibiotics is attracting considerable attention for inhibiting multi-drug resistant pathogenic bacteria. Although the therapy mostly leads to more powerful antimicrobial effects than using a single antibiotic (synergy), interference may arise from certain antibiotic combinations, resulting in the antimicrobial effect being suppressed (antagonism). Here, we present a microfluidic-based phenotypic screening chip to investigate combinatory antibiotic effects by automatically generating two orthogonal concentration gradients on a bacteria-trapping agarose gel...
February 15, 2019: Lab on a Chip
K C Andree, A Mentink, A T Nguyen, P Goldsteen, G van Dalum, J J Broekmaat, C J M van Rijn, L W M M Terstappen
The load of circulating tumor cells (CTC) is related to poor outcomes in cancer patients. A sufficient number of these cells would enable a full characterization of the cancer. An approach to probe larger blood volumes, allowing for the detection of more of these very rare CTC, is the use of leukapheresis. Currently available techniques allow only the analysis of a small portion of leukapheresis products. Here, we present a method that uses flow rather than static conditions which allows processing of larger volumes...
February 14, 2019: Lab on a Chip
Ali Lashkaripour, Christopher Rodriguez, Luis Ortiz, Douglas Densmore
The required step in all droplet-based devices is droplet formation. A droplet generator must deliver an application-specific performance that includes a prescribed droplet size and generation frequency while producing monodisperse droplets. The desired performance is usually reached through several cost- and time-inefficient design iterations. To address this, we take advantage of a low-cost rapid prototyping method and provide a framework that enables researchers to make informed decisions on how to change geometric parameters and flow conditions to tune the performance of a microfluidic flow-focusing droplet generator...
February 14, 2019: Lab on a Chip
Sangjo Shim, Maura C Belanger, Alexandra R Harris, Jennifer M Munson, Rebecca R Pompano
Experimentally accessible tools to replicate the complex biological events of in vivo organs offer the potential to reveal mechanisms of disease and potential routes to therapy. In particular, models of inter-organ communication are emerging as the next essential step towards creating a body-on-a-chip, and may be particularly useful for poorly understood processes such as tumor immunity. In this paper, we report the first multi-compartment microfluidic chip that continuously recirculates a small volume of media through two ex vivo tissue samples to support inter-organ cross-talk via secreted factors...
February 11, 2019: Lab on a Chip
Chen-Yin Ou, Tam Vu, Jonathan T Grunwald, Michael Toledano, Jan Zimak, Melody Toosky, Byron Shen, Jason A Zell, Enrico Gratton, Timothy J Abram, Weian Zhao
Current cancer detection systems lack the required sensitivity to reliably detect minimal residual disease (MRD) and recurrence at the earliest stages when treatment would be most effective. To address this issue, we present a novel liquid biopsy approach that utilizes an integrated comprehensive droplet digital detection (IC3D) digital PCR system which combines microfluidic droplet partitioning, fluorescent multiplex PCR chemistry, and our rapid 3D, large-volume droplet counting technology. The IC3D ddPCR assay can detect cancer-specific, ultra-rare genomic targets due to large sample input and high degree of partitioning...
February 8, 2019: Lab on a Chip
Jason E Kreutz, Jiasi Wang, Allison M Sheen, Alison M Thompson, Jeannette P Staheli, Michael R Dyen, Qinghua Feng, Daniel T Chiu
Digital nucleic acid amplification and detection methods provide excellent sensitivity and specificity and allow absolute quantification of target nucleic acids. Isothermal methods such as digital loop-mediated isothermal amplification (digital LAMP) have potential for use in rapid disease diagnosis in low-resource settings due to their speed and lack of thermal cycling. We previously developed a self-digitization (SD) chip, a simple microfluidics device that automatically digitizes a sample into an array of nanoliter wells, for use in digital LAMP...
February 8, 2019: Lab on a Chip
Mingguang Han, Jin Li, Gaohong He, Meng Lin, Wu Xiao, Xiangcun Li, Xuemei Wu, Xiaobin Jiang
Droplet evaporative crystallization on a micro-structured platform with limited interfacial area has potential applications in crystallization theory, bioengineering, and particle drug preparation. Here, an efficient and versatile approach is discussed for multiple drop-evaporative crystallization processes on a micro-crystallization chip fabricated via three-dimensional printing. A chip with limited interfacial area could be fabricated on a highly controlled crystallizer interface. During liquid injection, various drop locations and evaporative conditions can be used, which enables flexible and distinct crystallization processes...
February 7, 2019: Lab on a Chip
Hyou-Arm Joung, Zachary S Ballard, Alice Ma, Derek K Tseng, Hailemariam Teshome, Spencer Burakowski, Omai B Garner, Dino Di Carlo, Aydogan Ozcan
We developed a multiplexed point-of-care immunodiagnostic assay for antibody detection in human sera made through the vertical stacking of functional paper layers. In this multiplexed vertical flow immunodiagnostic assay (xVFA), a colorimetric signal is generated by gold nanoparticles captured on a spatially-multiplexed sensing membrane containing specific antigens. The assay is completed in 20 minutes, following which the sensing membrane is imaged by a cost-effective mobile-phone reader. The images are sent to a server, where the results are rapidly analyzed and relayed back to the user...
February 7, 2019: Lab on a Chip
Taylor Oeschger, Duncan McCloskey, Varun Kopparthy, Ankur Singh, David Erickson
Sepsis is a rapidly progressing, life threatening immune response triggered by infection that affects millions worldwide each year. Current clinical diagnosis relies on broad physiological parameters and time consuming lab-based cell culture. If proper treatment is not provided, cases of sepsis can drastically increase in severity over the course of a few hours. Development of new point of care tools for sepsis has the potential to improve diagnostic speed and accuracy, leading to prompt administration of appropriate therapeutics, thereby reducing healthcare costs and improving patient outcomes...
February 6, 2019: Lab on a Chip
Caitlin E Anderson, Joshua R Buser, Alexis M Fleming, Eva-Maria Strauch, Paula D Ladd, Janet Englund, David Baker, Paul Yager
Influenza is a viral respiratory tract infection responsible for up to 5 million cases of severe infection and nearly 600 000 deaths worldwide each year. While treatments for influenza exist, diagnostics for the virus at the point of care are limited in their sensitivity and ability to differentiate between subtypes. We have developed an integrated two-dimensional paper network (2DPN) for the detection of the influenza virus by the surface glycoprotein, hemagglutinin. The hemagglutinin assay was developed using proteins computationally designed to bind with high affinity to the highly-conserved sialic acid binding site...
February 6, 2019: Lab on a Chip
Daniel Green Marques, Pedro Alhais Lopes, Anibal T de Almeida, Carmel Majidi, Mahmoud Tavakoli
We tackle two well-known problems in the fabrication of stretchable electronics: interfacing soft circuit wiring with silicon chips and fabrication of multi-layer circuits. We demonstrate techniques that allow integration of embedded flexible printed circuit boards (FPCBs) populated with microelectronics into soft circuits composed of liquid metal (LM) interconnects. These methods utilize vertical interconnect accesses (VIAs) that are produced by filling LM alloy into cavities formed by laser ablation. The introduced technique is versatile, easy to perform, clean-room free, and results in reliable multi-layer stretchable hybrid circuits that can withstand over 80% of strain...
February 6, 2019: Lab on a Chip
Florian Larramendy, Shotaro Yoshida, Daniela Maier, Zoltan Fekete, Shoji Takeuchi, Oliver Paul
This paper addresses a nanoengineering approach to create a fully three-dimensional (3D) network of living cells, providing an advanced solution to in vitro studies on either neuronal networks or artificial organs. The concept of our work relies on stackable scaffolds composed of microcontainers designed and dimensioned to favor the geometrically constrained growth of cells. The container geometry allows cells to communicate in the culture medium and freely grow their projections to form a 3D arrangement of living cells...
February 6, 2019: Lab on a Chip
Alexander W Auner, Kazi M Tasneem, Dmitry A Markov, Lisa J McCawley, M Shane Hutson
Microfluidic organ-on-chip devices constructed from polydimethylsiloxane (PDMS) have proven useful in studying both beneficial and adverse effects of drugs, supplements, and potential toxicants. Despite multiple advantages, one clear drawback of PDMS-based devices is binding of hydrophobic chemicals to their exposed surfaces. Chemical binding to PDMS can change the timing and extent of chemical delivery to cells in such devices, potentially altering dose-response curves. Recent efforts have quantified PDMS binding for selected chemicals...
February 5, 2019: Lab on a Chip
Tingting Tao, Yaqing Wang, Wenwen Chen, Zhongyu Li, Wentao Su, Yaqiong Guo, Pengwei Deng, Jianhua Qin
Human pluripotent stem cell (hPSC)-derived islet cells provide promising resources for diabetes studies, cell replacement treatment and drug screening. Recently, hPSC-derived organoids have represented a new class of in vitro organ models for disease modeling and regenerative medicine. However, rebuilding biomimetic human islet organoids from hPSCs remains challenging. Here, we present a new strategy to engineer human islet organoids derived from human induced pluripotent stem cells (hiPSCs) using an organ-on-a-chip platform combined with stem cell developmental principles...
February 5, 2019: Lab on a Chip
Jonathan W Snow, Hatice Ceylan Koydemir, Doruk Kerim Karinca, Kyle Liang, Derek Tseng, Aydogan Ozcan
Recent declines in honey bee colonies in the United States have put increased strain on agricultural pollination. Nosema ceranae and Nosema apis, are microsporidian parasites that are highly pathogenic to honey bees and have been implicated as a factor in honey bee losses. While traditional methods for quantifying Nosema infection have high sensitivity and specificity, there is no field-portable device for field measurements by beekeepers. Here we present a field-portable and cost-effective smartphone-based platform for detection and quantification of chitin-positive Nosema spores in honey bees...
February 5, 2019: Lab on a Chip
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