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Lab on a Chip

Hui Li, Yi Lu, Pak Kin Wong
Amperometric biosensors are widely applied for rapid biomarker detection in physiological and environmental samples. The dynamics and linearity of the current signal, however, are only partially understood. This study investigates the diffusion-reaction kinetics of amperometric biosensing using a self-assembled monolayer (SAM) based biosensor for bacterial 16S rRNA. A numerical model is developed to optimize the chamber dimensions and elucidate the concentration dependences of the biosensor. The results revealed that depletion of substrates associated with the chamber dimension can limit the current signal in a target concentration dependent manner...
September 12, 2018: Lab on a Chip
Till Korten, Elena Tavkin, Lara Scharrel, Vandana Singh Kushwaha, Stefan Diez
Molecular motors, essential to force-generation and cargo transport within cells, are invaluable tools for powering nanobiotechnological lab-on-a-chip devices. These devices are based on in vitro motility assays that reconstitute molecular transport with purified motor proteins, requiring a deep understanding of the biophysical properties of motor proteins and thorough optimization to enable motility under varying environmental conditions. Until now, these assays have been prepared manually, severely limiting throughput...
September 11, 2018: Lab on a Chip
Yasmín R Álvarez-García, Karla P Ramos-Cruz, Reinaldo J Agostini-Infanzón, Loren E Stallcop, David J Beebe, Jay W Warrick, Maribella Domenech
The study of multi-cell-type (MCT) interactions has the potential to significantly impact our understanding of tissue and disease biology. Such studies require innovative culture tools for unraveling the contributions of each cell type. Micro- and macro-scale platforms for MCT culture each have different advantages and disadvantages owing to their widely different capabilities, availability, and ease-of-use. However, as evidenced in the literature, there are very few examples of MCT studies and culture platforms, suggesting both biological and technical barriers...
September 11, 2018: Lab on a Chip
Emanuel Berger, Chiara Magliaro, Nicole Paczia, Anna S Monzel, Paul Antony, Carole L Linster, Silvia Bolognin, Arti Ahluwalia, Jens C Schwamborn
Human midbrain-specific organoids (hMOs) serve as an experimental in vitro model for studying the pathogenesis of Parkinson's disease (PD). In hMOs, neuroepithelial stem cells (NESCs) give rise to functional midbrain dopaminergic (mDA) neurons that are selectively degenerating during PD. A limitation of the hMO model is an under-supply of oxygen and nutrients to the densely packed core region, which leads eventually to a "dead core". To reduce this phenomenon, we applied a millifluidic culture system that ensures media supply by continuous laminar flow...
September 11, 2018: Lab on a Chip
Sahand Saberi-Bosari, Javier Huayta, Adriana San-Miguel
Aging produces a number of changes in the neuronal structure and function throughout a variety of organisms. These aging-induced changes encompass a wide range of phenotypes, from loss of locomotion ability to defective production of synaptic vesicles. C. elegans is one of the primary systems used to elucidate phenotypes associated with aging processes. Conventional aging studies in C. elegans are typically labor-intensive, low-throughput, and incorporate fluorodeoxyuridine (FUdR) as a sterilizing agent to keep the population age-synchronized throughout the assay...
September 7, 2018: Lab on a Chip
Colin L Hisey, Kalpana Deepa Priya Dorayappan, David E Cohn, Karuppaiyah Selvendiran, Derek J Hansford
Exosomes are nanoscale vesicles found in many bodily fluids which play a significant role in cell-to-cell signaling and contain biomolecules indicative of their cells of origin. Recently, microfluidic devices have provided the ability to efficiently capture exosomes based on specific membrane biomarkers, but releasing the captured exosomes intact and label-free for downstream characterization and experimentation remains a challenge. We present a herringbone-grooved microfluidic device which is covalently functionalized with antibodies against general and cancer exosome membrane biomarkers (CD9 and EpCAM) to isolate exosomes from small volumes of high-grade serous ovarian cancer (HGSOC) serum...
September 7, 2018: Lab on a Chip
Mathias Schlenk, Markus Drechsler, Matthias Karg, Walter Zimmermann, Martin Trebbin, Stephan Förster
The control of the distribution of colloidal particles in microfluidic flows plays an important role in biomedical and industrial applications. A particular challenge is to induce cross-streamline migration in laminar flows, enabling the separation of colloidal particles according to their size, shape or elasticity. Here we show that viscoelastic fluids can mediate cross-streamline migration of deformable spherical and cylindrical colloidal particles in sinusoidal microchannels at low Reynolds numbers. For colloidal streams focused into the center of the channel entrance this leads to a symmetric stream-splitting and separation into four substreams...
September 6, 2018: Lab on a Chip
Amir R Aref, Marco Campisi, Elena Ivanova, Andrew Portell, Dalia Larios, Brandon P Piel, Natasha Mathur, Chensheng Zhou, Raven Vlahos Coakley, Alan Bartels, Michaela Bowden, Zach Herbert, Sarah Hill, Sean Gilhooley, Jacob Carter, Israel Cañadas, Tran C Thai, Shunsuke Kitajima, Valeria Chiono, Cloud P Paweletz, David A Barbie, Roger D Kamm, Russell W Jenkins
Microfluidic culture has the potential to revolutionize cancer diagnosis and therapy. Indeed, several microdevices are being developed specifically for clinical use to test novel cancer therapeutics. To be effective, these platforms need to replicate the continuous interactions that exist between tumor cells and non-tumor cell elements of the tumor microenvironment through direct cell-cell or cell-matrix contact or by the secretion of signaling factors such as cytokines, chemokines and growth factors. Given the challenges of personalized or precision cancer therapy, especially with the advent of novel immunotherapies, a critical need exists for more sophisticated ex vivo diagnostic systems that recapitulate patient-specific tumor biology with the potential to predict response to immune-based therapies in real-time...
September 5, 2018: Lab on a Chip
Cong Wu, Xiongfeng Zhu, Tianxing Man, Pei-Shan Chung, Michael A Teitell, Pei-Yu Chiou
We developed a highly efficient method for patterning cells by a novel and simple technique called lift-off cell lithography (LCL). Our approach borrows the key concept of lift-off lithography from microfabrication and utilizes a fully biocompatible process to achieve high-throughput, high-efficiency cell patterning with nearly zero background defects across a large surface area. Using LCL, we reproducibly achieved >70% patterning efficiency for both adherent and non-adherent cells with <1% defects in undesired areas...
September 5, 2018: Lab on a Chip
George A Truskey
A number of major disease states involve skeletal muscle, including type 2 diabetes, muscular dystrophy, sarcopenia and cachexia arising from cancer or heart disease. Animals do not accurately represent many of these disease states. Human skeletal muscle microphysiological systems derived from primary or induced pluripotent stem cells (hPSCs) can provide an in vitro model of genetic and chronic diseases and assess individual variations. Three-dimensional culture systems more accurately represent skeletal muscle function than do two-dimensional cultures...
September 5, 2018: Lab on a Chip
Wei Cai, Yu-Jui Chiu, Valya Ramakrishnan, Yihuan Tsai, Clark Chen, Yu-Hwa Lo
Understanding biological heterogeneity at the single cell level is required for advancing insights into the complexity of human physiology and diseases. While advances in technological and analytical methods have afforded unprecedented glimpses of this heterogeneity, the information captured to date largely represents one-time "snap" shots of single cell physiology. To address the limits of existing methods and to accelerate discoveries from single cell studies, we developed a single-cell translocation and secretion assay (TransSeA) that supports time lapse analysis, enables molecular cargo analysis of secretions such as extracellular vesicles (EVs) from single cells, allows massively parallel single cell transfer according to user-defined cell selection criteria, and supports tracking of phenotypes between parental and progeny cells derived from single cells...
September 4, 2018: Lab on a Chip
Paulina Bryl-Górecka, Ramasri Sathanoori, Mariam Al-Mashat, Björn Olde, Jonas Jögi, Mikael Evander, Thomas Laurell, David Erlinge
Extracellular vesicles (EVs) are a heterogeneous group of actively released vesicles originating from a wide range of cell types. Characterization of these EVs and their proteomes in the human plasma provides a novel approach in clinical diagnostics, as they reflect physiological and pathological states. However, EV isolation is technically challenging with the current methods having several disadvantages, requiring large sample volumes, and resulting in loss of sample and EV integrity. Here, we use an alternative, non-contact method based on a microscale acoustic standing wave technology...
September 4, 2018: Lab on a Chip
Alexander M Xu, Qianhe Liu, Kaitlyn L Takata, Sarah Jeoung, Yapeng Su, Igor Antoshechkin, Sisi Chen, Matthew Thomson, James R Heath
Biological function arises from the interplay of proteins, transcripts, and metabolites. An ongoing revolution in miniaturization technologies has created tools to analyze any one of these species in single cells, thus resolving the heterogeneity of tissues previously invisible to bulk measurements. An emerging frontier is single cell multi-omics, which is the measurement of multiple classes of analytes from single cells. Here, we combine bead-based transcriptomics with microchip-based proteomics to measure intracellular proteins and transcripts from single cells and defined small numbers of cells...
September 4, 2018: Lab on a Chip
Maria Alejandra Lizarralde Iragorri, Sara El Hoss, Valentine Brousse, Sophie D Lefevre, Michael Dussiot, Tieying Xu, Alexander Rodrigo Ferreira, Yann Lamarre, Ana Cristina Silva Pinto, Simone Kashima, Claudine Lapouméroulie, Dimas Tadeu Covas, Caroline Le Van Kim, Yves Colin, Jacques Elion, Olivier Français, Bruno Le Pioufle, Wassim El Nemer
The human red blood cell is a biconcave disc of 6-8 × 2 μm that is highly elastic. This capacity to deform enables it to stretch while circulating through narrow capillaries to ensure its main function of gas exchange. Red cell shape and deformability are altered in membrane disorders because of defects in skeletal or membrane proteins affecting protein-protein interactions. Red cell properties are also altered in other pathologies such as sickle cell disease. Sickle cell disease is a genetic hereditary disorder caused by a single point mutation in the β-globin gene generating sickle haemoglobin (HbS)...
August 31, 2018: Lab on a Chip
Jong Seok Park, Sandra I Grijalva, Moez K Aziz, Taiyun Chi, Sensen Li, Michael N Sayegh, Adam Wang, Hee Cheol Cho, Hua Wang
Cells are complex systems with concurrent multi-physical responses, and cell physiological signals are often encoded with spatiotemporal dynamics and further coupled with multiple cellular activities. However, most existing electronic sensors are only single-modality and cannot capture multi-parametric cellular responses. In this paper, a 1024-pixel CMOS quad-modality cellular interfacing array that enables multi-parametric cell profiling for drug development is presented. The quad-modality CMOS array features cellular impedance characterization, optical detection, extracellular potential recording, and biphasic current stimulation...
August 31, 2018: Lab on a Chip
F Zhou, Y Chen, E I Felner, C Zhu, H Lu
Cell adhesion plays a critical role in many cellular functions, such as the hemostatic/thrombotic process, inflammatory reactions, and adaptive immune response. Many cell adhesion processes involve crosstalk between multiple ligand-receptor systems through intracellular signaling. To elucidate such crosstalk requires analysis of the synergistic or antagonistic effects of binding and signalling of multi-receptor species. Current techniques for these analyses, e.g., atomic force microscopy (AFM) and biomembrane force probe (BFP) assays, are either labor-intensive, low-throughput, or limited in the types of ligands they can interrogate...
August 31, 2018: Lab on a Chip
Stephanie J Hachey, Christopher C W Hughes
Over the past six decades the inflation-adjusted cost to bring a new drug to market has been increasing constantly and doubles every 9 years - now reaching in excess of $2.5 billion. Overall, the likelihood of FDA approval for a drug (any disease indication) that has entered phase I clinical trials is a mere 9.6%, with the approval rate for oncology far below average at only 5.1%. Lack of efficacy or toxicity is often not revealed until the later stages of clinical trials, despite promising preclinical data...
August 29, 2018: Lab on a Chip
Pieter E Oomen, Yanxi Zhang, Ryan C Chiechi, Elisabeth Verpoorte, Klaus Mathwig
We suspended a single nanoskived gold nanowire in a microfluidic channel. In this preliminary report, a 200 nm-diameter nanowire was used as an electrode to perform hydrodynamic voltammetry in the center of solution flow. Suspended nanowires exhibit superior current response due to highly efficient mass transport in the area of fastest flow.
August 29, 2018: Lab on a Chip
Jinsoo Park, Ghulam Destgeer, Hyoungsoo Kim, Yeunwoo Cho, Hyung Jin Sung
Washing and enrichment of particles and cells are crucial sample preparation procedures in biomedical and biochemical assays. On-chip in-droplet microparticle washing and enrichment have been pursued but remained problematic due to technical difficulties, especially simultaneous and precise control over the droplet interface and in-droplet samples. Here, we have achieved a breakthrough in label-free, continuous, on-demand, in-droplet microparticle washing and enrichment using surface acoustic waves. When exposed to the acoustic field, the droplet and suspended particles experience acoustic radiation force arising from inhomogeneous wave scattering at the liquid/liquid and liquid/solid interfaces...
August 24, 2018: Lab on a Chip
Azeem Ahmad, Vishesh Dubey, Vijay Raj Singh, Jean-Claude Tinguely, Cristina Ionica Øie, Deanna L Wolfson, Dalip Singh Mehta, Peter T C So, Balpreet Singh Ahluwalia
Red blood cells (RBCs) have the ability to undergo morphological deformations during microcirculation, such as changes in surface area, volume and sphericity. Optical waveguide trapping is suitable for trapping, propelling and deforming large cell populations along the length of the waveguide. Bright field microscopy employed with waveguide trapping does not provide quantitative information about structural changes. Here, we have combined quantitative phase microscopy and waveguide trapping techniques to study changes in RBC morphology during planar trapping and transportation...
August 22, 2018: Lab on a Chip
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