Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Tiny Biomolecular Tweezers Facilitate Study of Mechanical Force Effects on Cells and Proteins

Conceptual design of MAP-nDEP tweezers. a) Schematic of chip layout: Circu-lar magnetic nickel pads (blue) were flanked by interdigitated gold electrodes (red). b) Paramagnetic beads were introduced to chip surface by microfluidics and loaded onto the magnetic pads by magnetic manipulation, facilitating the formation of bead-surface tethers via antibody-antigen interactions. c) Interac-tions probed by application of sufficient nDEP force to displace non-specifically bound beads, but not specifi cally bound beads. d) Microfabrication process.
Conceptual design of MAP-nDEP tweezers. a) Schematic of chip layout: Circu-lar magnetic nickel pads (blue) were flanked by interdigitated gold electrodes (red). b) Paramagnetic beads were introduced to chip surface by microfluidics and loaded onto the magnetic pads by magnetic manipulation, facilitating the formation of bead-surface tethers via antibody-antigen interactions. c) Interac-tions probed by application of sufficient nDEP force to displace non-specifically bound beads, but not specifi cally bound beads. d) Microfabrication process.

Abstract:
A new type of biomolecular tweezers could help researchers study how mechanical forces affect the biochemical activity of cells and proteins. The devices - too small to see without a micro-scope - use opposing magnetic and electrophoretic forces to precisely stretch the cells and molecules, holding them in position so that the activity of receptors and other biochemical activ-ity can be studied. Arrays of the tweezers could be combined to study multiple molecules and cells simultaneously, providing a high throughput capability for assessing the effects of mechani-cal forces on a broad scale. Details of the devices, which were developed by researchers at the Georgia Institute of Technology and Emory University in Atlanta, were published February 19, 2014, in the journal Technology.

Tiny Biomolecular Tweezers Facilitate Study of Mechanical Force Effects on Cells and Proteins

Singapore | Posted on April 3rd, 2014

"Our lab has been very interested in mechanical-chemical switches in the extracellular matrix, but we currently have a difficult time interrogating these mechanisms and discovering how they work in vivo," said Thomas Barker, an associate professor in the Wallace H. Coulter, Department of Biomedical Engineering at Georgia Tech and Emory University. "This device could help biologists and biomedical engineers answer questions that cannot be answered right now." For example, a cell that's binding the extracellular matrix may bind with one receptor while the matrix is being stretched, and a different receptor when it's not under stress. Those binding differences could drive changes in cell phenotype and affect processes such as cell differ-entiation. But they are now difficult to study.

"Having a device like this will allow us to interrogate what the specific binding sites are and what the specific binding triggers are," Barker explained. "Right now, we know very little about this area when it comes to protein biochemistry." Scientists have been able to study how single cells or proteins are affected by mechanical forces, but their activity can vary considerably from cell-to-cell and among molecules. Th e new tweezers, which are built using nanolithogra-phy, can facilitate studying thousands or more cells and proteins in aggregate. The researchers are currently testing prototype 15 by 15 arrays which they believe could be scaled up.

"For me, it's not sufficient to pull and hold onto a single protein," said Barker. "I have to pull and hold onto tens of thousands of proteins to really use the technologies we have to develop molecular probes."

At the center of the tweezers are 2.8-micron polystyrene microbeads that contain super-paramagnetic nanoparticles. The tiny beads are engineered to adhere to a sample being studied. That sample is attached to a bead on one side, and to a magnetic pad on the other. The magnet draws the bead toward it, while an electrophoretic force created by current flowing through a gold wiring pattern pushes the bead away. "The device simultaneously pushes and pulls on the same particle," Barker explained. "This allows us to hold the sample at a very specific position above the magnet." Because the forces can be varied, the tweezers can be used to study structures of widely different size scales, from protein molecules to cells - a size difference of approximately a thousand times, noted Wilbur Lam, an assistant professor in the Coulter Department. Absolute forces in the nano-Newton range applied by the two sources overcome the much smaller effects of Brownian motion and thermal energy, allowing the tweezers to hold the cells or molecules without constant adjustment.

"We are basically leveraging microchip technology that has been developed by electrical and mechanical engineers," Lam noted. "We are able to leverage these very tiny features that en-able us to create a very sharp electrical field on one end against an opposing short magnetic field. Because there are two ways of controlling it, we have tight resolution and can get to many differ-ent scales."

As a proof of principle for the system, the researchers demonstrated its ability to distin-guish between antigen binding to loaded magnetic beads coated with different antibodies. When a sufficient upward force is applied, non-specific antibody coated beads are displaced from the an-tigen-coated device surface, while beads coated with the specific antibody are more strongly at-tracted to the surface and retained on it.

Barker and Lam began working together on the tweezers three years ago when they real-ized they had similar interests in studying the effects of mechanical action on different biological systems. "We shouldn't be surprised that biology can be dictated by physical parameters," Lam explained. "Everything has to obey the laws of physics, and mechanics gets to the heart of that." Lam's interest is at the cellular scale, specifically in blood cells.

"Blood cells also respond differently, biologically, when you squeeze them and when you stretch them," he said. "For instance, we have learned that mechanics has a lot to do with athero-sclerosis, but the systems we currently have for studying this mechanism can only look at single-cell events. If you can look at many cells at once, you get a much better statistical view of what's happening."

"We are primarily interested in evolving antibodies that are capable of distinguishing dif-ferent force-medicated conformations of proteins," he explained. "We have a specific protein that we are interested in, but this technique could be applied to any proteins that are suspected to have these force-activated changes in their biochemical activity." While the tweezers solve the specific experimental needs of Lam and Barker, the researchers hope to find other applications. The tweezers were developed in collaboration with graduate student Lizhi Cao and post-doctoral fel-low Zhengchun Peng. "Because of the scale we are able to examine - both molecular and cellu-lar - I think this will have a lot of applications both in protein molecular engineering and bio-technology," Lam said. "This could be a useful way for people to screen relevant molecules be-cause there currently aren't good ways to do that." Beyond biological systems, the device could be used in materials development, microelectronics and even sensing. "This ability to detect dis-crete binding and unbinding events between molecular species is of high interest right now," Barker added. "Biosensor applications come out of this naturally."

Corresponding author for this study in TECHNOLOGY is Thomas Barker, .

####

About World Scientific
World Scientific Publishing is a leading independent publisher of books and journals for the scholarly, research and professional communities. The company publishes about 500 books annually and more than 120 journals in various fields. World Scientific collaborates with prestigious organisations like the Nobel Foundation, US National Academies Press, as well as its subsidiary, the Imperial College Press, amongst others, to bring high quality academic and professional content to researchers and academics worldwide. To find out more about World Scientific, please visit www.worldscientific.com.

About TECHNOLOGY

Fashioned as a high-impact, high-visibility, top-echelon publication, this new ground-breaking journal - TECHNOLOGY - will feature the development of cutting-edge new technologies in a broad array of emerging fields of science and engineering. The content will have an applied science and technological slant with a focus on both innovation and application to daily lives. It will cover diverse disciplines such as health and life science, energy and environment, advanced materials, technology-based manufacturing, information science and technology, and marine and transportations technologies.

For more information, please click here

Contacts:
Chew Munkit

656-466-5775

Copyright © World Scientific

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Chemical trickery corrals 'hyperactive' metal-oxide cluster December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Nanomedicine

Arrowhead Pharmaceuticals to Webcast Fiscal 2016 Year End Results December 7th, 2016

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Journal Nanotechnology Progress International (JONPI) Volume 6, issue 2 coming out soon! December 5th, 2016

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Discoveries

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Researchers peer into atom-sized tunnels in hunt for better battery: May improve lithium ion for larger devices, like cars December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Announcements

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Researchers peer into atom-sized tunnels in hunt for better battery: May improve lithium ion for larger devices, like cars December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Researchers peer into atom-sized tunnels in hunt for better battery: May improve lithium ion for larger devices, like cars December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Nanobiotechnology

Arrowhead Pharmaceuticals to Webcast Fiscal 2016 Year End Results December 7th, 2016

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Nanobiotix Provides Update on Global Development of Lead Product NBTXR3: Seven clinical trials across the world: More than 2/3 of STS patients recruited in the “act.in.sarc” Phase II/III trial: Phase I/II prostate cancer trial now recruiting in the U.S. November 28th, 2016

Printing/Lithography/Inkjet/Inks/Bio-printing

Bumpy surfaces, graphene beat the heat in devices: Rice University theory shows way to enhance heat sinks in future microelectronics November 29th, 2016

Engineers develop new magnetic ink to print self-healing devices that heal in record time November 7th, 2016

Iran to hold intl. school on application of nanomaterials in medicine September 20th, 2016

Tailored probes for atomic force microscopes: 3-D laser lithography enhances microscope for studying nanostructures in biology and engineering/ publication in Applied Physics Letters August 11th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project