Hot Articles – Page 14 – Lab on a Chip Blog

Archive for the ‘Hot Articles’ Category

Point-of-care diagnostics using capillary forces – a HOT article!

18 Jan 2013

Point-of-care diagnostics is the aim for much medical research. Often the problem is the ease of preparation of the biological sample, which usually requires multiple steps before the diagnostic test can even begin. Automation of sample preparation has been explored and another option is pressure-driven microfluidics. However, this requires complex external equipment to run the chip only suitable for use in the laboratory away from the patient.

To get true point-of-care diagnostics, sample preparation has to be fast, simple and cheap.

Stationary microfluidics is now being explored. Liquid is present in fixed positions on the chip and it is magnetic particles that move between the points holding liquid. This often involves separating the liquids using an oil barrier, but this has disadvantages of over-complicating the device by having more than one liquid (the test solution), meaning an additional very careful pipetting step. Not all test solutions or all diagnostic tests would be compatible with this oil barrier, for example, purification of protein. Oil-free versions are now being designed, usually “open droplet” devices, but this again needs accurate pipetting and risks contamination of the sample. Using a large tube limits the miniaturisation capability.

Menno Prins has led a team based at Philips Research and Eindhoven University of Technology, The Netherlands, to solve this problem. They demonstrate technology called Magneto–Capillary Valve (MCV) technology. There is no need for an oil phase. The confinement of the liquid occurs by capillary forces and they can be separated by a gas. The device operation is a balancing act between magnetic and capillary forces.

In this HOT article, they give numerous device architectures and clearly demonstrate the advantages of this technique in purifying and enriching nucleic acids and proteins. They look in detail at how the device works and its applicability for a wide range of problems in point-of-care-diagnostics.

This research is best read in detail, and as this HOT article is free to access for the next 4 weeks*, you can give it a read now by clicking on the link below:

Magneto-capillary valve for integrated purification and enrichment of nucleic acids and proteins
Remco C. den Dulk, Kristiane A. Schmidt, Gwénola Sabatté, Susana Liébana and Menno W. J. Prins
DOI: 10.1039/C2LC40929A

*Free access to individuals is provided through an RSC Publishing personal account. Registration is quick, free and simple

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Microdevices in cell biology: not one, but three HOT articles!

14 Jan 2013

Britta Weinhausen and Sarah Köster study hydrated eukaryotic cells device using X-rays in a new microfluidic device in their Technical Innovation, free to access for 4 weeks*.

The team at Georg-August-Universität Göttinghen, Germany, overcome some of the limitations of previous work to create a new type of device suitable for studying hydrated cells, with the possibility of applying it to living cells.

They use UV-curable glue (NOA 81) allowing sophisticated channel structures to be defined, two thin Kapton foils, with advantageous properties for X-ray studies, and a Si₃N₄ membrane window, upon which cells can be grown and fixed before the device is closed with a second membrane. Despite the small difference in electron density between the cellular material and water, they successfully produce X-ray dark-field images:

Microfluidic devices for X-ray studies on hydrated cells
Britta Weinhausen and Sarah Köster
DOI: 10.1039/C2LC41014A

As mentioned in the LOC issue 2 blog, Luke Lee et al. at the University of California, Berkeley and Stanford University, featured on the front cover with their work on sorting stem cells using a cell cytometer based on the electrophysiological response to stimulus. As a HOT article that was featured on the cover, this article has been free to access* for 6 weeks from mid-December so get your skates on to read it in full in the next week:

Label-free electrophysiological cytometry for stem cell-derived cardiomyocyte clusters
Frank B. Myers, Christopher K. Zarins, Oscar J. Abilez and Luke P. Lee
DOI: 10.1039/C2LC40905D

In this Technical Innovation, Rashid Bashir led a team of researchers from the USA, Sweden and Singapore in using silicon nanowires for rapid lysis of single cells by ultra-localized electroporation to release cell components for analysis. They integrate label-free magnetic manipulation to correctly position cells with the use of field effect transistors to apply an electric field for cell lysis.

Their method eliminates the use of microfluidic trapping techniques, transparent substrates for optical tweezing and high voltages, amongst other requirements for previous devices.

This work is featured on the inside front cover of Issue 3, so it’s currently free to access for 6 weeks*. Do have a read of the article here:

Ultra-localized single cell electroporation using silicon nanowires
Nima Jokilaakso, Eric Salm, Aaron Chen, Larry Millet, Carlos Duarte Guevara, Brian Dorvel, Bobby Reddy, Amelie Eriksson Karlstrom, Yu Chen, Hongmiao Ji, Yu Chen, Ratnasingham Sooryakumar and Rashid Bashir
DOI: 10.1039/C2LC40837F

*Free access to individuals is provided through an RSC Publishing personal account. Registration is quick, free and simple

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HOT article: A hydrodynamic study on streamer formation in biofilms

09 Jan 2013

Researchers led by Aloke Kumar at the Oak Ridge National Laboratory, USA, and Thomas Thundat at the University of Alberta, Canada, used a porous microfluidic device to study biofilm streamer development in porous media.

The microfluidic method allowed close observation and measurement of streamers developing between microposts embedded in a microchannel. The formation of streamers in the device forming a web connecting different microposts was strongly influenced by the hydrodynamics.

Higher flow rates resulted in thicker structures and higher numbers of streamers as they grew much faster. At very high flow rate, their formation was only transient as they were destabilized after forming. The fluid flow seems to be the cause of both the formation and destabilization of the streamers. Interestingly, streamers formed parallel to the flow direction in regions of high flow rate and transverse to it in regions of low flow rate. In contrast with a previous report, they observe streamers distributed throughout the height of the device, attributed to secondary flow in the corners of the device. Carrying out numerical simulations, Kumar and Thundat et al. showed that secondary flows in the z-direction do not have a large role to play.

Development of streamers is complex and a great deal of detail remains to be elucidated, however, this Lab on a Chip article indicates that streamer formation might lead to mature microbial structures under the right conditions.

This HOT article is free to access* on our site for the next four weeks, so why not download the paper here:

A web of streamers: biofilm formation in a porous microfluidic device
Amin Valiei , Aloke Kumar , Partha P. Mukherjee , Yang Liu and Thomas Thundat
DOI: 10.1039/C2LC40815E

*Free access to individuals is provided through an RSC Publishing personal account. Registration is quick, free and simple

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LOC issue 2 – sorting stem cell-derived cardiomyocyte clusters, cross talk between cancer and immune cells and Genome Sequence Scanning

21 Dec 2012

Welcome to Issue 2 of Lab on a Chip! This issue features the winner of the Lab on a Chip Pioneers of Miniaturisation Lectureship, Andrew deMello, on the back cover. Read more about this award and others given at MicroTAS here.

On the front cover of issue 2 is featured work from the group of Luke Lee at the University of California, Berkeley, in conjunction with colleagues at Stanford University.

In the paper, the authors use a ‘non-genetic, label-free cell cytometry method based on electrophysiological response to stimulus’ to sort undifferentiated stem cells from heterogeneous stem cell progeny.

The cell cytometer can identify human induced pluripotent stem cell-derived cardiomyocyte clusters from their extracellular field potential signals – these stem cells can then be used for various stem cell therapies.

Label-free electrophysiological cytometry for stem cell-derived cardiomyocyte clusters
Frank B. Myers, Christopher K. Zarins, Oscar J. Abilez and Luke P. Lee
DOI: 10.1039/C2LC40905D

Work from the Italian National Research Council – Institute for Photonics and Nanotechnologies and the Istituto Superiore di Sanità is featured on the inside front cover.

The groups, led by Fabrizio Mattei and Luca Businaro, have used an on-chip co-culture system to investigate interactions between cancer cells and a host’s immune system.

Cross talk between cancer and immune cells: exploring complex dynamics in a microfluidic environment
Luca Businaro, Adele De Ninno, Giovanna Schiavoni, Valeria Lucarini, Gabriele Ciasca, Annamaria Gerardino, Filippo Belardelli, Lucia Gabriele and Fabrizio Mattei
DOI: 10.1039/C2LC40887B

On the inside back cover, work from Robert Meltzer and co-workers at Pathogenetix, Inc. is featured.

In their paper, they present a novel compound funnel design for use with Genome Sequence Scanning (GSS) technology, which improves molecule throughput.

High-throughput genome scanning in constant tension fluidic funnels
Joshua W. Griffis, Ekaterina Protozanova, Douglas B. Cameron and Robert H. Meltzer
DOI: 10.1039/C2LC40943G

As with all our cover articles these are free to access for 6 weeks (following a simple registration for an RSC Publishing account).

Other HOT articles featured in the issue include:

Benchtop fabrication of microfluidic systems based on curable polymers with improved solvent compatibility
Michinao Hashimoto, Robert Langer and Daniel S. Kohane
DOI: 10.1039/C2LC40888K

Microfluidic assisted self-assembly of chitosan based nanoparticles as drug delivery agents
Fatemeh Sadat Majedi, Mohammad Mahdi Hasani-Sadrabadi, Shahriar Hojjati Emami, Mohammad Ali Shokrgozar, Jules John VanDersarl, Erfan Dashtimoghadam, Arnaud Bertsch and Philippe Renaud
DOI: 10.1039/C2LC41045A

Microfluidic devices for X-ray studies on hydrated cells
Britta Weinhausen and Sarah Köster
DOI: 10.1039/C2LC41014A

For even more exciting microfluidics research, read the full issue here.

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Idea featured in Lab on a Chip article to benefit from the RSC’s support of Marblar

13 Nov 2012

The RSC has teamed up with an Oxford University spin-out to sponsor six challenges on Marblar – a radical new online platform for finding applications for unused scientific discoveries.

More than 95% of technologies developed in universities never make it to market, leaving publicly or philanthropy-funded research collecting dust on the shelf. Often, given that academic research can be so ahead of its time, the commercial relevance of these technologies isn’t immediately obvious.

Marblar aims to remove this bottleneck by crowdsourcing ideas for real-world applications from the global science and technology community, with the ultimate goal to create new products and new companies that will drive job creation around these innovative discoveries.

An idea from one Lab on a Chip article – SlipChip – has been chosen as one of the RSC sponsored challenges.

SlipChip is a low-cost microfluidic device that uses only two pieces of plastic or glass to enable the user to perform multiple small-scale chemical reactions simply and precisely. By simply ‘slipping’ the glass or plastic ‘chips’ across each other, a number of reactions can be carried out in nanoscale volumes in parallel.

SlipChip was developed at the University of Chicago by Professor Rustem Ismagilov and his then graduate student, Feng Shen. They’ve since created a spinout company called SlipChip based on this technology and Ismagilov has continued his work at the California Institute of Technology. Given the technology’s ability to precisely manipulate reactions in a programmable way, they see applications in multiple fields. Through Marblar, they hope to find ideas beyond their discipline that can exploit SlipChip’s ability to ‘count molecules’, as well as new capabilities for the technology.

Visit the Marblar website to get involved, or read the Lab on a Chip article below:

Digital PCR on a SlipChip
Feng Shen, Wenbin Du, Jason E. Kreutz, Alice Fok and Rustem F. Ismagilov
DOI: 10.1039/C004521G

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Issue 22 – Focus on Scandinavia

30 Oct 2012

Issue 22 of Lab on a Chip features work from Scandinavia – read the editorial from the Guest Editors Professors Thomas Laurell and Jörg Kutter here. The issue features 8 articles from Scandinavian authors, and profiles of the athours included can be found here.

The front cover features work from Jörg Kutter and co-workers at the Technical University of Denmark, reporting on the optical properties of gold nanoparticle probes, used as sensors for environmental contaminants.

Gold nanoparticle-based optical microfluidic sensors for analysis of environmental pollutants
Josiane P. Lafleur, Silja Senkbeil, Thomas G. Jensen and Jörg P. Kutter
DOI: 10.1039/C2LC40543A

Artwork linked to research from Vincent Aimez and colleagues from the Université de Sherbrooke can be seen on the inside front cover of the issue – they have developed a microfluidic device to monitor the radioactivity concentration in the blood of rats and mice in real time.

Blood compatible microfluidic system for pharmacokinetic studies in small animals
Laurence Convert, Frédérique Girard Baril, Vincent Boisselle, Jean-François Pratte, Réjean Fontaine, Roger Lecomte, Paul G. Charette and Vincent Aimez
DOI: 10.1039/C2LC40550D

The back cover of the issue features work from Samir Iqbal and co-workers at the University of Texas and Lehigh University. The team designed a Hele-Shaw device with aptamer functionalized glass beads to isolate cancer cells from a cellular mixture.

Capture, isolation and release of cancer cells with aptamer-functionalized glass bead array
Yuan Wan, Yaling Liu, Peter B. Allen, Waseem Asghar, M. Arif Iftakher Mahmood, Jifu Tan, Holli Duhon, Young-tae Kim, Andrew D. Ellington and Samir M. Iqbal
DOI: 10.1039/C2LC21251J

Other HOT papers in the issue include:

Two-hundredfold volume concentration of dilute cell and particle suspensions using chip integrated multistage acoustophoresis
Maria Nordin and Thomas Laurell
DOI: 10.1039/C2LC40629B

Inertial microfluidics in parallel channels for high-throughput applications
Jonas Hansson, J. Mikael Karlsson, Tommy Haraldsson, Hjalmar Brismar, W. van der Wijngaart and Aman Russom
DOI: 10.1039/C2LC40241F

Low cost integration of 3D-electrode structures into microfluidic devices by replica molding
Benjamin Mustin and Boris Stoeber
DOI: 10.1039/C2LC40728K

A microfluidic device with removable packaging for the real time visualisation of intracellular effects of nanosecond electrical pulses on adherent cells
C. Dalmay, M. A. De Menorval, O. Français, L. M. Mir and B. Le Pioufle
DOI: 10.1039/C2LC40857K

Programmable microfluidic synthesis of spectrally encoded microspheres
R. E. Gerver, R. Gómez-Sjöberg, B. C. Baxter, K. S. Thorn, P. M. Fordyce, C. A. Diaz-Botia, B. A. Helms and J. L. DeRisi
DOI: 10.1039/C2LC40699C

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Hot articles from our Emerging Investigators

20 Sep 2012

We’re delighted to announce the publication of our 2012 Emerging Investigators issue, which contains a massive 6 HOT articles! Read the editorial from Amy Herr and Aaron Wheeler to find out why this group of researchers is affectionately known as control freaks..

Controllable microfluidic production of gas-in-oil-in-water emulsions for hollow microspheres with thin polymer shells
Ran Chen, Peng-Fei Dong, Jian-Hong Xu, Yun-Dong Wang and Guang-Sheng Luo
DOI: 10.1039/C2LC40387K

A rotary microsystem for simple, rapid and automatic RNA purification
Byung Hyun Park, Jae Hwan Jung, Hainan Zhang, Nae Yoon Lee and Tae Seok Seo
DOI: 10.1039/C2LC40487G

Cytotoxicity analysis of water disinfection byproducts with a micro-pillar microfluidic device
Austin Hsiao, Yukako Komaki, Syed M. Imaad, Benito J. Mariñas, Michael J. Plewa and G. Logan Liu
DOI: 10.1039/C2LC40374A

Highly sensitive and quantitative detection of rare pathogens through agarose droplet microfluidic emulsion PCR at the single-cell level
Zhi Zhu, Wenhua Zhang, Xuefei Leng, Mingxia Zhang, Zhichao Guan, Jiangquan Lu and Chaoyong James Yang
DOI: 10.1039/C2LC40461C

Enantioselective analysis of melagatran via an LSPR biosensor integrated with a microfluidic chip
Longhua Guo, Yuechun Yin, Rong Huang, Bin Qiu, Zhenyu Lin, Huang-Hao Yang, Jianrong Li and Guonan Chen
DOI: 10.1039/C2LC40388A

Real-time full-spectral imaging and affinity measurements from 50 microfluidic channels using nanohole surface plasmon resonance
Si Hoon Lee, Nathan C. Lindquist, Nathan J. Wittenberg, Luke R. Jordan and Sang-Hyun Oh
DOI: 10.1039/C2LC40455A

These articles will be free to access for the next 4 weeks. (Free access to individuals is provided through an RSC Publishing personal account. Registration is quick, free and simple.)

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Body heat could drive drug delivery

14 Sep 2012

Another Lab on a Chip article has been picked up by the press, describing a nifty micropump which is powered by fermentation of yeast. Manuel Ochoa and Babak Ziaie, Purdue University, created the “microorganism-powered thermopneumatic pump” by stacking PDMS layers with a silicon substrate drug reservoir and a chamber for the yeast. They showed that when the yeast ferments under body temperatures, the micropump could displace the drug in the reservoir. The technology has caused excitement due to its potential for use in transdermal drug delivery patches, by driving tiny microneedle arrays.

A fermentation-powered thermopneumatic pump for biomedical applications
Manuel Ochoa and Babak Ziaie
DOI: 10.1039/C2LC40620A

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Article on light-activated muscle has people twitching

04 Sep 2012

A collaborative study by Harry Asada (MIT) and Roger Kamm (Penn State) and colleagues just published in Lab on a Chip has been causing a bit of a stir on the blogosphere recently. The article describes the stimulation of muscle, not by electrical signals as used in the body, but by light. The team engineered skeletal muscle tissue to contain a light-responsive protein, which allowed it to contract when blue light was shone on it, as shown in the video below from the MIT press release:

Jumping straight from this amazing achievement to the future, several blogs have already discussed the potential of this technology for advanced biorobotics (this article was our favourite). Professor Asada is a little more modest and discusses the potential of the engineered muscle to control endoscopes or be used in drug screening programmes.

Read the paper here or take a look at some of the posts on the topic:

siliconANGLE
Judgement Day Beckons: Scientists Grow ‘Light-Activated’ Muscle Tissue For Robots

Wired
Light-activated skeletal muscle could be used to make realistic robots

The Verge
Laser-stimulated muscle tissue could be used to build ‘bio-integrated’ robots

Machines like us
Researchers engineer light-activated skeletal muscle

Formation and optogenetic control of engineered 3D skeletal muscle bioactuators
Mahmut Selman Sakar, Devin M Neal, Thomas Boudou, Michael A Borochin, Yinqing Li, Ron Weiss, Roger Kamm, Christopher S. Chen and H Harry Asada
Lab Chip, 2012, Accepted Manuscript
DOI: 10.1039/C2LC40338B

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Hot articles in optofluidics

29 Aug 2012

You might have already seen our themed issue on optofluidics but in case you haven’t, here are the HOT articles from this issue:

Yi-Chung Tung et al. review the recent advances in optofluidic technologies that will open up new possibilities for on-chip phenotyping

Optofluidic detection for cellular phenotyping
Yi-Chung Tung, Nien-Tsu Huang, Bo-Ram Oh, Bishnubrata Patra, Chi-Chun Pan, Teng Qiu, Paul K. Chu, Wenjun Zhang and Katsuo Kurabayashi
DOI: 10.1039/C2LC40509A

Kevin Raymond et al. have developed an ‘optofluidic nose’ for sensing organic liquids based on wetting in photonic-crystal arrays.

Combinatorial wetting in colour: an optofluidic nose
Kevin P. Raymond, Ian B. Burgess, Mackenzie H. Kinney, Marko Lončar and Joanna Aizenberg
DOI: 10.1039/C2LC40489C

Haiwang Li and colleagues demonstrate the design of a bi-concave lens to perform both light focusing and diverging in-plane.

An electrokinetically tunable optofluidic bi-concave lens
Haiwang Li, Chaolong Song, Trung Dung Luong, Nam-Trung Nguyen and Teck Neng Wong
DOI: 10.1039/C2LC40406K

Yasutaka Hanada and coworkers show how to create a highly sensitive optofluidic chip for biochemical liquid assays by coating microfluidic channels with a low refractive index polymer and use of an optical waveguide.

Highly sensitive optofluidic chips for biochemical liquid assay fabricated by 3D femtosecond laser micromachining followed by polymer coating
Yasutaka Hanada, Koji Sugioka and Katsumi Midorikawa
DOI: 10.1039/C2LC40377C

Jigang Wu, Guoan Zheng and Lap Man Lee focus on compact systems in their review of optical imaging techniques that can be integrated with microfluidics.

Optical imaging techniques in microfluidics and their applications
DOI: 10.1039/C2LC40517B

Chao-Min Cheng and colleagues provide thoughtful insight into the application of optofluidics to synthetic biology in this forward-looking Frontier article.

Frontiers of optofluidics in synthetic biology
Cheemeng Tan, Shih-Jie Lo, Philip R. LeDuc and Chao-Min Cheng
DOI: 10.1039/C2LC40828G

Shih-Kang Fan’s team manipulate 200 nL bubbles with DEP and ignite microplasma within them, with potential for future applications in the biomedical field.

Atmospheric-pressure microplasma in dielectrophoresis-driven bubbles for optical emission spectroscopy
Shih-Kang Fan, Yan-Ting Shen, Ling-Pin Tsai, Cheng-Che Hsu, Fu-Hsiang Ko and Yu-Ting Cheng
DOI: 10.1039/C2LC40499K

Wenqi Hu, Kelly S. Ishii, Qihui Fan and Aaron T. Ohta report a hydrogel microrobot which can be manipulated by laser-induced bubbles. Single or pairs of robots are able to assemble polystyrene beads and yeast cells into patterns.

Hydrogel microrobots actuated by optically generated vapour bubbles
Wenqi Hu, Kelly S. Ishii, Qihui Fan and Aaron T. Ohta
DOI: 10.1039/C2LC40483D

Remember, all our cover articles are free to access for 6 weeks, and our HOT articles for 4 weeks. All you need to access them is an RSC Publishing Personal Account – signing up is quick and easy.

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Lab on a Chip Blog

Archive for the ‘Hot Articles’ Category

Point-of-care diagnostics using capillary forces – a HOT article!

Microdevices in cell biology: not one, but three HOT articles!

HOT article: A hydrodynamic study on streamer formation in biofilms

LOC issue 2 – sorting stem cell-derived cardiomyocyte clusters, cross talk between cancer and immune cells and Genome Sequence Scanning

Idea featured in Lab on a Chip article to benefit from the RSC’s support of Marblar

Issue 22 – Focus on Scandinavia

Hot articles from our Emerging Investigators

Body heat could drive drug delivery

Article on light-activated muscle has people twitching

Hot articles in optofluidics

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