Read by QxMD icon Read


Hagit Stauber, Dan Waisman, Netanel Korin, Josué Sznitman
The pulmonary capillary networks (PCNs) embody organ-specific microvasculatures, where blood vessels form dense meshes that maximize the surface area available for gas exchange in the lungs. With characteristic capillary lengths and diameters similar to the size of red blood cells (RBCs), seminal descriptions coined the term "sheet flow" nearly half a century ago to differentiate PCNs from the usual notion of Poiseuille flow in long straight tubes. Here, we revisit in true-scale experiments the original "sheet flow" model and devise for the first time biomimetic microfluidic platforms of organ-specific PCN structures perfused with RBC suspensions at near-physiological hematocrit levels...
January 10, 2017: Biomicrofluidics
Pavan K Challa, Tadas Kartanas, Jérôme Charmet, Tuomas P J Knowles
Current lithography approaches underpinning the fabrication of microfluidic devices rely on UV exposure of photoresists to define microstructures in these materials. Conventionally, this objective is achieved with gas discharge mercury lamps, which are capable of producing high intensity UV radiation. However, these sources are costly, have a comparatively short lifetime, necessitate regular calibration, and require significant time to warm up prior to exposure taking place. To address these limitations we exploit advances in solid state sources in the UV range and describe a fast and robust wafer-scale laboratory exposure system relying entirely on UV-Light emitting diode (UV-LED) illumination...
January 2017: Biomicrofluidics
E Salimi, K Braasch, M Butler, D J Thomson, G E Bridges
Applying sufficiently strong pulsed electric fields to a cell can permeabilize the membrane and subsequently affect its dielectric properties. In this study, we employ a microfluidic dielectrophoresis cytometry technique to simultaneously electroporate and measure the time-dependent dielectric response of single Chinese hamster ovary cells. Using experimental measurements along with numerical simulations, we present quantitative results for the changes in the cytoplasm conductivity of single cells within seconds after exposure to 100 μs duration pulsed electric fields with various intensities...
January 2017: Biomicrofluidics
Liang Huang, Shengtai Bian, Yinuo Cheng, Guanya Shi, Peng Liu, Xiongying Ye, Wenhui Wang
Single cell analysis has received increasing attention recently in both academia and clinics, and there is an urgent need for effective upstream cell sample preparation. Two extremely challenging tasks in cell sample preparation-high-efficiency cell enrichment and precise single cell capture-have now entered into an era full of exciting technological advances, which are mostly enabled by microfluidics. In this review, we summarize the category of technologies that provide new solutions and creative insights into the two tasks of cell manipulation, with a focus on the latest development in the recent five years by highlighting the representative works...
January 2017: Biomicrofluidics
J A Moore, M Nemat-Gorgani, A C Madison, M A Sandahl, S Punnamaraju, A E Eckhardt, M G Pollack, F Vigneault, G M Church, R B Fair, M A Horowitz, P B Griffin
This paper reports on the use of a digital microfluidic platform to perform multiplex automated genetic engineering (MAGE) cycles on droplets containing Escherichia coli cells. Bioactivated magnetic beads were employed for cell binding, washing, and media exchange in the preparation of electrocompetent cells in the electrowetting-on-dieletric (EWoD) platform. On-cartridge electroporation was used to deliver oligonucleotides into the cells. In addition to the optimization of a magnetic bead-based benchtop protocol for generating and transforming electrocompetent E...
January 2017: Biomicrofluidics
Qiangyuan Zhu, Lin Qiu, Yanan Xu, Guang Li, Ying Mu
Single cell analysis provides a new framework for understanding biology and disease, however, an absolute quantification of single cell gene expression still faces many challenges. Microfluidic digital polymerase chain reaction (PCR) provides a unique method to absolutely quantify the single cell gene expression, but only limited devices are developed to analyze a single cell with detection variation. This paper describes a self-priming compartmentalization (SPC) microfluidic digital polymerase chain reaction chip being capable of performing single molecule amplification from single cell...
January 2017: Biomicrofluidics
Xiaoxiao Chen, Thomas F Leary, Charles Maldarelli
Arrays of probe molecules integrated into a microfluidic cell are utilized as analytical tools to screen the binding interactions of the displayed probes against a target molecule. These assay platforms are useful in enzyme or antibody discovery, clinical diagnostics, and biosensing, as their ultraminiaturized design allows for high sensitivity and reduced consumption of reagents and target. We study here a platform in which the probes are first grafted to microbeads which are then arrayed in the microfluidic cell by capture in a trapping course...
January 2017: Biomicrofluidics
Cristina Gaspar, Tiina Sikanen, Sami Franssila, Ville Jokinen
We demonstrate a combined printing process utilizing inkjet printing of silver electrodes and solid-ink technology for printing hydrophobic wax barriers for fabricating paper microfluidic devices with integrated electrodes. Optimized printing parameters are given for achieving conducting silver lines on the top of macroporous chromatography paper down to 250 μm-300 μm resolution. Electrical characterization and wicking experiments demonstrate that the printed silver patterns are simultaneously conductive and porous enough to allow reliable capillary wicking across the electrodes...
November 2016: Biomicrofluidics
Yingying Zhao, Qin Li, Xiaoming Hu, Yuhwa Lo
A microfluidic cytometer with integrated on-chip optical systems was designed for red blood cell (RBC) and platelet (PLT) counting. The design, fabrication, and characterization of the microfluidic cytometer with on-chip optical signal detection were described. With process using only a single mask, the device that integrates optical fibers and on-chip microlens with microfluidic channels on a polydimethylsiloxane layer by standard soft photolithography. This compact structure increased the sensitivity of the device and eliminated time-consuming free-space optical alignments...
November 2016: Biomicrofluidics
Hoyoon Lee, Gyehyu Kim, Chaeseung Lim, ByoungKwon Lee, Sehyun Shin
High-shear stimulation is well known as one of the key factors affecting platelet activation and aggregation, which can lead to the formation of a thrombus. In one of our previous studies, we introduced migration distance-based platelet function analysis in a microfluidic system. In this study, we set out to examine the effects of stirring on shear-induced platelet activation and aggregation in a chamber system by using a rotating stirrer. We found that the rotating stirrer caused not only rotational shear flow but also a strong radial secondary flow...
November 2016: Biomicrofluidics
Yousef M F El Hasadi, Martin Crapper
Self-propelled clusters are involved in many technological applications such as in material science and biotechnology, and understanding their interaction with the fluid that surrounds them is of a great importance. We present results of swimming velocity and energy dissipation obtained through Stokesian dynamics simulations of self-propelled clusters. The clusters are of diffusion limited aggregates, consisting of force- and torque-free spherical particles. The number of particles per cluster ranges from 100 to 400, and with two fractal dimensions of 2...
November 2016: Biomicrofluidics
H Cai, M A Stott, D Ozcelik, J W Parks, A R Hawkins, H Schmidt
We have developed an optofluidic analysis system that processes biomolecular samples starting from whole blood and then analyzes and identifies multiple targets on a silicon-based molecular detection platform. We demonstrate blood filtration, sample extraction, target enrichment, and fluorescent labeling using programmable microfluidic circuits. We detect and identify multiple targets using a spectral multiplexing technique based on wavelength-dependent multi-spot excitation on an antiresonant reflecting optical waveguide chip...
November 2016: Biomicrofluidics
Qiushui Chen, Dong Chen, Jing Wu, Jin-Ming Lin
Designing cell-compatible, bio-degradable, and stimuli-responsive hydrogels is very important for biomedical applications in cellular delivery and micro-scale tissue engineering. Here, we report achieving flexible control of cellular microencapsulation, permeability, and release by rationally designing a diblock copolymer, alginate-conjugated poly(N-isopropylacrylamide) (Alg-co-PNiPAM). We use the microfluidic technique to fabricate the bifunctional copolymers into thousands of mono-disperse droplet-templated hydrogel microparticles for controlled encapsulation and triggered release of mammalian cells...
November 2016: Biomicrofluidics
David Dannhauser, Filippo Causa, Edmondo Battista, Angela M Cusano, Domenico Rossi, Paolo A Netti
We present an in-flow ultrasensitive fluorescence detection of microRNAs (miRNAs) using spectrally encoded microgels. We researched and employed a viscoelastic fluid to achieve an optimal alignment of microgels in a straight measurement channel and applied a simple and inexpensive microfluidic layout, allowing continuous fluorescence signal acquisitions with several emission wavelengths. In particular, we chose microgels endowed with fluorescent emitting molecules designed for multiplex spectral analysis of specific miRNA types...
November 2016: Biomicrofluidics
Zhen Li, Qiaohui Luo, Jianmin Wu
A label-free optical sensor was constructed by integrating electrochemically etched porous silicon (pSi) and supported phospholipid bilayers in a microfluidic chip. The translocation of peptides through the phospholipid bilayers could induce a red shift in effective optical thickness of the pSi layer, which could be monitored by reflective interferometric Fourier transform spectroscopy. By measuring the kinetic data of membrane translocating on the phospholipid bilayers/pSi chip, the relationship between the behavior of membrane-translocating peptides (MTPs) and translocating mechanism was established...
November 2016: Biomicrofluidics
Debarati De, Madhuri Mandal Goswami
This paper reports a very simple yet better method for synthesis of cube shaped magnetite nanoparticles (MNPs) and their application in the drug delivery system (DDS). Structural analysis was done by XRD measurements to confirm the phase of the material, and morphological information was obtained through TEM analysis to confirm the shape and size of the particles. It has been shown that these particles can be decomposed in acid medium. These acid-decomposable magnetite nano-particles have been used for heat triggered, remote-controlled, on demand delivery and release of a cancer drug doxorubicin for research and therapeutic purposes...
November 2016: Biomicrofluidics
Ramtin Ardeshiri, Ben Mulcahy, Mei Zhen, Pouya Rezai
C. elegans is a well-known model organism in biology and neuroscience with a simple cellular (959 cells) and nervous (302 neurons) system and a relatively homologous (40%) genome to humans. Lateral and longitudinal manipulation of C. elegans to a favorable orientation is important in many applications such as neural and cellular imaging, laser ablation, microinjection, and electrophysiology. In this paper, we describe a micro-electro-fluidic device for on-demand manipulation of C. elegans and demonstrate its application in imaging of organs and neurons that cannot be visualized efficiently under natural orientation...
November 2016: Biomicrofluidics
Young Kwon Kim, Ju An Park, Woong Hee Yoon, Joonwon Kim, Sungjune Jung
We present drop-on-demand inkjet-based mammalian cell printing with a 30-μm nozzle diameter for cell-level accuracy. High-speed imaging techniques have been used to analyze the go-and-stop movement of cells inside the nozzle under a pulsed pressure generated by a piezo-actuator and the jet formation after ejection. Patterning of an array of 20 × 20 dots on a glass substrate reveals that each printed drop contains 1.30 cells on average at the cell concentration of 5.0 × 10(6) cells ml(-1) for the very small nozzle, whereas larger nozzles with the diameter of 50 and 80 μm deliver 2...
November 2016: Biomicrofluidics
Timothy Lannin, Wey-Wey Su, Conor Gruber, Ian Cardle, Chao Huang, Fredrik Thege, Brian Kirby
We used automated electrorotation to measure the cytoplasmic permittivity, cytoplasmic conductivity, and specific membrane capacitance of pancreatic cancer cells under environmental perturbation to evaluate the effects of serum starvation, epithelial-to-mesenchymal transition, and evolution of chemotherapy resistance which may be associated with the development and dissemination of cancer. First, we compared gemcitabine-resistant BxPC3 subclones with gemcitabine-naive parental cells. Second, we serum-starved BxPC3 and PANC-1 cells and compared them to untreated counterparts...
November 2016: Biomicrofluidics
Minsub Han, Byoung Choul Kim, Toshiki Matsuoka, M D Thouless, Shuichi Takayama
This paper uses computer simulations to reveal unprecedented details about linearization of deoxyribonucleic acid (DNA) inside dynamic nanochannels that can be repeatedly widened and narrowed. We first analyze the effect of rate of channel narrowing on DNA linearization dynamics. Quick (∼0.1 s) narrowing of nanoscale channels results in rapid overstretching of the semi-flexible chain followed by a slower (∼0.1-10 s) relaxation to an equilibrium extension. Two phenomena that induce linearization during channel narrowing, namely, elongational-flow and confinement, occur simultaneously, regardless of narrowing speed...
November 2016: Biomicrofluidics
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"