Read by QxMD icon Read

Lab on a Chip

Yuan-Sheng Lee, Nirveek Bhattacharjee, Albert Folch
Here we demonstrate a 3D-printable microvalve that is transparent, built with a biocompatible resin, and has a simple architecture that can be easily scaled up into large arrays. The open-at-rest valve design is derived from Quake's PDMS valve design. We used a stereolithographic (SL) 3D printer to print a thin (25 or 10 μm-thick) membrane (1200 or 500 μm-diam.) that is pneumatically pressed (∼3-6 psi) over a bowl-shaped seat to close the valve. We used poly(ethylene diacrylate) (MW = 258) (PEG-DA-258) as the resin because it yields transparent cytocompatible prints...
March 19, 2018: Lab on a Chip
Guanghui Wang, Jie Tan, Minghui Tang, Changbin Zhang, Dongying Zhang, Wenbin Ji, Junhao Chen, Ho-Pui Ho, Xuping Zhang
Centrifugal microfluidics or lab-on-a-disc (LOAD) is a promising branch of lab-on-a-chip or microfluidics. Besides effective fluid transportation and inherently available density-based sample separation in centrifugal microfluidics, uniform actuation of flow on the disc makes the platform compact and scalable. However, the natural radially outward centrifugal force in a LOAD system limits its capacity to perform complex fluid manipulation steps. In order to increase the fluid manipulation freedom and integration capacity of the LOAD system, we propose a binary centrifugal microfluidics platform...
March 16, 2018: Lab on a Chip
Yuanyuan Fan, Defang Dong, Qingling Li, Haibin Si, Haimeng Pei, Lu Li, Bo Tang
Single-cell analysis of bioactive molecules is an essential strategy for a better understanding of cell biology, exploring cell heterogeneity, and improvement of the ability to detect early diseases. In single-cell analysis, highly efficient single-cell manipulation techniques and high-sensitive detection schemes are in urgent need. The rapid development of fluorescent analysis techniques combined with microfluidic chips have offered a widely applicable solution. Thus, in this review, we mainly focus on the application of fluorescence methods in components analysis on microchips at a single-cell level...
March 15, 2018: Lab on a Chip
Hiroki Yasuga, Koki Kamiya, Shoji Takeuchi, Norihisa Miki
Two-dimensional (2D) microdroplet arrays with indexed sample concentration gradients have been receiving considerable attention for high-throughput biological and medical analyses. However, the preparation of such an array by conventional methods mandates precise pipetting and/or pumping. In this paper, we introduce a method to spontaneously generate 2D-arrayed aqueous droplets using a well array, for which coarse pipetting is sufficient. The wells are connected in rows and columns via narrow channels. Aqueous solutions impregnated in the well array are split into droplets in every single well as a subsequently introduced immiscible solvent self-propagates and divides the solution at the channels...
March 15, 2018: Lab on a Chip
Michael A Luzuriaga, Danielle R Berry, John C Reagan, Ronald A Smaldone, Jeremiah J Gassensmith
Biodegradable polymer microneedle (MN) arrays are an emerging class of transdermal drug delivery devices that promise a painless and sanitary alternative to syringes; however, prototyping bespoke needle architectures is expensive and requires production of new master templates. Here, we present a new microfabrication technique for MNs using fused deposition modeling (FDM) 3D printing using polylactic acid, an FDA approved, renewable, biodegradable, thermoplastic material. We show how this natural degradability can be exploited to overcome a key challenge of FDM 3D printing, in particular the low resolution of these printers...
March 14, 2018: Lab on a Chip
Lu Huang, Yin Chen, Wei Huang, Hongkai Wu
Here a convenient and effective strategy of two-step centrifugation-assisted single-cell trapping (CAScT) based on an addressable truncated cone-shaped microwell array (TCMA) chip is developed for cell pairing. We describe the operation principles of the method and demonstrate its compatibility with polyethylene glycol (PEG)-mediated cell fusion. Compared with other methods, most of which rely on sophisticated devices and bulky subsidiary equipment, our method is more convenient and exhibits better or comparable performance...
March 14, 2018: Lab on a Chip
Guijun Chen, Xiaohua Liu, Sufen Li, Ming Dong, Dongyue Jiang
When a water droplet slides down a hydrophobic surface, a major energy it possesses is kinetic energy. However, people may ignore another important energy source: triboelectrification. To quantify and utilize triboelectrification energy, a phenomenon is presented in this study: one droplet slides down a tilted chip with a hydrophobic coating and patterned electrodes, triboelectrification happens and the induced charges are transferred to another horizontally placed chip with copper wires, on which another droplet is actuated by the transferred charges...
March 14, 2018: Lab on a Chip
Yankai Jia, Yukun Ren, Likai Hou, Weiyu Liu, Tianyi Jiang, Xiaokang Deng, Ye Tao, Hongyuan Jiang
Controlled release of multiple actives after encapsulation in a microenvironment is significant for various biological and chemical applications such as controlled drug delivery and transplantation of encapsulated cells. However, traditional systems often lack efficient encapsulation and release of multiple actives, especially when incorporated substances must be released at a targeted location. Here, we present a straightforward approach to release multiple actives at a prescribed position in microfluidic systems; one or two actives are encapsulated in water-in-oil-in-water emulsion droplets, followed by controlled release of the actives via an alternating current electric field...
March 14, 2018: Lab on a Chip
M Sanz, J A Picazo-Bueno, J García, V Micó
We report on a novel layout capable of dual-mode imaging in real time with different magnifications and resolution capabilities in lensless microscopy. The concept is based on wavelength multiplexing for providing two illuminations with different wavefront curvatures: one is collimated, allowing a large field of view (FOV) with a poor resolution limit, and the other is divergent, to achieve a better resolution limit (micron range) over a small FOV. Moreover, our recently reported concept of MISHELF microscopy [M...
March 13, 2018: Lab on a Chip
Therese W Herling, Aviad Levin, Kadi L Saar, Christopher M Dobson, Tuomas P J Knowles
The self-assembly of proteins into supramolecular structures and machinery underpins biological activity in living systems. Misassembled, misfolded and aggregated protein structures can, by contrast, have deleterious activity and such species are at the origin of a number of disease states ranging from cancer to neurodegenerative disorders. In particular, the formation of highly ordered protein aggregates, amyloid fibrils, from normally soluble peptides and proteins, is the common pathological hallmark of a range a group of over fifty protein misfolding disorders...
March 12, 2018: Lab on a Chip
Pooria Hadikhani, S Mohammad H Hashemi, Gioele Balestra, Lailai Zhu, Miguel A Modestino, François Gallaire, Demetri Psaltis
Inertial microfluidics is an active field of research that deals with crossflow positioning of the suspended entities in microflows. Until now, the majority of the studies have focused on the behavior of rigid particles in order to provide guidelines for microfluidic applications such as sorting and filtering. Deformable entities such as bubbles and droplets are considered in fewer studies despite their importance in multiphase microflows. In this paper, we show that the trajectory of bubbles flowing in rectangular and square microchannels can be controlled by tuning the balance of forces acting on them...
March 7, 2018: Lab on a Chip
Yu-Cheng Chen, Qiushu Chen, Xiaoqin Wu, Xiaotian Tan, Juanhong Wang, Xudong Fan
Laser emission-based detection and imaging technology has attracted significant interest in biomedical research due to its high sensitivity, narrow linewidth, and superior spectral and spatial resolution. Recent advances have further revealed the potential to use laser emission to investigate chromatin dynamics, as well as to diagnose cancer tissues based on nuclear biomarkers. To move the laser emission based detection technology a step further towards practical use, in this work, we developed a highly robust tissue laser platform by microfabricating an SU8 spacer with a fixed height on the top mirror of the Fabry-Pérot (FP) cavity, which allows generation of reproducible and stable lasing results regardless of tissue thickness...
March 7, 2018: Lab on a Chip
Min Jung Kim, Jae Ryoun Youn, Young Seok Song
Extracellular polymeric substances (EPSs) are self-produced biosynthetic macromolecules that have a three-dimensional architecture in bacterial biofilms and are mainly composed of a mixture of polysaccharides, proteins and nucleic acids. Compared with synthetic polymers, EPSs can have a long relaxation time due to their structural complexity. We exploited the non-Newtonian rheological behavior of EPSs extracted from Chlorella vulgaris with the help of cell focusing and particle focusing in confined microchannels...
March 6, 2018: Lab on a Chip
R W Liefferink, A Naillon, D Bonn, M Prat, N Shahidzadeh
The behaviour of minerals (i.e. salts) such as sodium chloride and calcite in porous media is very important in various applications such as weathering of artworks, oil recovery and CO2 sequestration. We report a novel method for manufacturing single layer porous media in which minerals can be entrapped in a controlled way in order to study their dissolution and recrystallization. In addition, our manufacturing method is a versatile tool for creating monomodal, bimodal or multimodal pore size microporous media with controlled porosity ranging from 25% to 50%...
March 5, 2018: Lab on a Chip
Jérémy Decock, Mathias Schlenk, Jean-Baptiste Salmon
We report the fabrication of highly permeable membranes in poly(ethylene glycol) diacrylate (PEGDA) channels, for investigating ultra- or micro-filtration, at the microfluidic scale. More precisely, we used a maskless UV projection setup to photo-pattern PEG-based hydrogel membranes on a large scale (mm-cm), and with a spatial resolution of a few microns. We show that these membranes can withstand trans-membrane pressure drops of up to 7 bar without any leakage, thanks to the strong anchoring of the hydrogel to the channel walls...
February 28, 2018: Lab on a Chip
Ehsan Akbari, Griffin B Spychalski, Kaushik K Rangharajan, Shaurya Prakash, Jonathan W Song
Endothelial barrier function is known to be regulated by a number of molecular mechanisms; however, the role of biomechanical signals associated with blood flow is comparatively less explored. Biomimetic microfluidic models comprised of vessel analogues that are lined with endothelial cells (ECs) have been developed to help answer several fundamental questions in endothelial mechanobiology. However, previously described microfluidic models have been primarily restricted to single straight or two parallel vessel analogues, which do not model the bifurcating vessel networks typically present in physiology...
February 28, 2018: Lab on a Chip
Anil Kumar Pulikkathodi, Indu Sarangadharan, Yi-Hong Chen, Geng-Yen Lee, Jen-Inn Chyi, Gwo-Bin Lee, Yu-Lin Wang
In this research, we have designed, fabricated and characterized an electrical double layer (EDL)-gated AlGaN/GaN high electron mobility transistor (HEMT) biosensor array to study the transmembrane potential changes of cells. The sensor array platform is designed to detect and count circulating tumor cells (CTCs) of colorectal cancer (CRC) and investigate cellular bioelectric signals. Using the EDL FET biosensor platform, cellular responses can be studied in physiological salt concentrations, thereby eliminating complex automation...
February 28, 2018: Lab on a Chip
Lei Bao, Vamsi Spandan, Yantao Yang, Brendan Dyett, Roberto Verzicco, Detlef Lohse, Xuehua Zhang
The dissolution of liquid nanodroplets is a crucial step in many applied processes, such as separation and dispersion in the food industry, crystal formation of pharmaceutical products, concentrating and analysis in medical diagnosis, and drug delivery in aerosols. In this work, using both experiments and numerical simulations, we quantitatively study the dissolution dynamics of femtoliter surface droplets in a highly ordered array under a uniform flow. Our results show that the dissolution of femtoliter droplets strongly depends on their spatial positions relative to the flow direction, drop-to-drop spacing in the array, and the imposed flow rate...
February 28, 2018: Lab on a Chip
Shuli Wang, Yongshun Liu, Peng Ge, Qiqi Kan, Nianzuo Yu, Jing Wang, Jingjie Nan, Shunsheng Ye, Junhu Zhang, Weiqing Xu, Bai Yang
This article shows a new strategy for the fabrication of nanofluidics based on nanoscale gaps in nanopillar arrays. Silicon nanopillar arrays are prepared in a designed position by combining conventional photolithography with colloidal lithography. The nanogaps between the pillars are used as nanochannels for the connection of two polydimethylsiloxane-based microchannels in microfluidics. The gap between neighbouring nanopillars can be accurately controlled by changing the size of initial colloidal spheres and by an etching process, which further determines the dimensions of the nanochannels...
February 27, 2018: Lab on a Chip
Yun Tang, Quan-Fa Qiu, Fu-Li Zhang, Min Xie, Wei-Hua Huang
Regeneration of injured neurons in complicated three-dimensional (3D) microenvironments is a key approach for treating neurodegenerative diseases. Microfluidics provides a versatile tool to recapitulate cellular microenvironments in vitro, but it still remains a big challenge to construct a microfluidic platform incorporating extracellular matrix (ECM) structures and highly controlled 3D gradients of soluble factors to study the regeneration of injured neurons. In this work, we developed a microfluidic device which can provide multiple adjustable gradients in a 3D ECM to investigate the regeneration of injured central nervous system (CNS) neurons in response to natural small molecules...
February 27, 2018: Lab on a Chip
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"