Subscribe free to our newsletters via your
. 24/7 Space News .




TECH SPACE
Study reveals novel technique for handling molecules
by Staff Writers
Tempe AZ (SPX) Apr 01, 2015


Figure shows hydrogel-aptamer capture and release. The hydrogel can be made sensitive to environmental variables. In the current study, changes in solution pH cause the hydrogel to either swell or contract. High pH produces a swollen state, causing slender probes or aptamers (seen in blue) to extend, like the claws of a kitten. These aptamers, (short DNA, RNA or peptide molecules sensitive to specific chemical targets), extend into a mixed solution in an upper compartment of the device, exposing them to the molecules with which they bind. When the pH of the hydrogel is reduced and the environment becomes acidic, the hydrogel contracts, causing the aptamer probes to relax, pulling away the bound molecules (orange and yellow), which are released and free to re-circulate. Image courtesy The Biodesign Institute at Arizona State University. For a larger version of this image please go here.

Like vast international trading companies, biological systems pick up freight items (in the form of small molecules), transport them from place to place and release them at their proper destination. These ubiquitous processes are critical for activities ranging from photosynthesis to neuronal signaling.

The efficient capture, transport and release of molecules is also vital for the maintenance of equilibrium (or homeostasis), essential to all living things.

In research appearing in the current issue of the journal Nature Chemistry, Ximin He, Ph.D., and her colleagues* describe a method capable of mimicking Nature's ability to sort, capture, transport and release molecules. The technique sets the stage for continuous and efficient manipulation of a broad range of molecules of relevance to human and environmental health.

Professor He is a researcher at Arizona State University's Biodesign Institute, where she recently joined the Center for Molecular Design and Biomimetics. (The Center is under the direction of Hao Yan, Ph.D., who holds the Martin D. Glick Distinguished Professor chair in the College of Liberal Arts and Sciences, Chemistry and Biochemistry.)

Material world
Much of He's research, the current project included, centers around the design of energy-efficient, environmentally-responsive materials and devices capable of reacting to environmental cues, adapting their behaviors and exhibiting self-regulation. Such biomimetic analogues show remarkable potential for applications ranging from biological/chemical sensing and separation to energy harvesting and conversion.

"Biological systems use feedback as a crucial component to provide efficient performance. Yet, the use of feedback has not been exploited to a sufficient extent in the design of new material systems," He says. "We must learn how to engineer responsiveness to environmental changes and the ability to perform important functions into the framework of new materials. In this research, the components are integrated to enable adaptive functionality and encompass feedback."

The highly interdisciplinary research integrates chemistry, materials science, and mechanical engineering, in addition to biology. It has broad implications in diverse fields ranging from biotechnology and biomedicine to chemical engineering and environmental remediation.

Recipes of Nature
Continuous self-monitoring and self-regulation are hallmarks of living systems, which seamlessly convert chemical to mechanical energy and vice versa, subtly adjusting their state as environmental conditions change. For these purposes, macromolecular components capable of converting chemical events into mechanical motion or vice versa are needed. Transformations of chemical and mechanical energy are essential for organismic self-regulation and survival and are responsible for such phenomena as ATP synthesis and muscle contraction.

Researchers would like to create synthetic materials that can emulate this behavior, but the task has been challenging. Typically, synthetic materials operate in only one direction, either transforming chemical to mechanical energy or the reverse, and tend to be responsive to a limited chemical repertoire.

In contrast, the method described in the new study offers great versatility, permitting the capture, transport and release of specific target molecules from complex mixed solutions. The approach described could be applied for sustained-release drug delivery systems, new generations of ultra-sensitive diagnostics and chemical sensing devices.

In addition to applications in biomedicine, the technique's ability to extract a range of components from chemically complex solutions could one day be applied as an energy-efficient means of removing waste from the environment, capturing valuable minerals, performing desalinization of sea water or trawling for hazardous substances like radioactive nuclides or heavy metals in rivers and streams. The method is rapid and suitable for numerous biological and biomedical applications that require separation of sub-microliter samples for downstream analysis.

Unlike most existing methods, the new technique can operate autonomously, mimicking the self-regulatory nature of living systems, through interconnected feedback loops. This property allows the system to operate with high efficiency and reliability without the need for external energy sources like laser, infrared, magnetic or electric fields used in conventional materials and devices.

Sifting for molecules
At the heart of the new system is a substance known as a hydrogel, a highly absorbent polymer that can mimic certain properties of living tissue. Indeed, hydrogels are sometimes applied as scaffolds for cell cultures used to repair damaged tissue.

Some hydrogels also display a delicately tunable sensitivity to their environment. These hydrogels--sometimes referred to as 'Smart Gels'--can sense subtle changes in their surroundings, including alterations of temperature, pH or metabolite concentration. In response, the hydrogel may expand or contract, and in the process, cause the binding or release specified target molecules, under proper conditions, (see Figure 1).

In the current study, researchers designed a chemomechanical system using aptamers capable of detecting the human enzyme, thrombin. (Aptamers are DNA, RNA or peptide molecules sensitive to specific chemical targets). Binding aptamers for thrombin were used to decorate microscopic fins embedded in a pH-responsive hydrogel.

Changes in pH and resulting expansion or contraction of the hydrogel moves the thrombin-sensitive aptamers--which are also pH-sensitive--between the two chemically distinct environments. Under low pH, the aptamers denature, losing their affinity for thrombin, further assisting in thrombin release coinciding with hydrogel contraction.

Findings
The system showed efficient and reversible sorting, binding, transport and release of thrombin under sensitive pH control. With pH adjusted to a range of 6-7, binding occurs, followed by molecule release when pH falls below 5. The authors liken the process to kinesins and dyneins--naturally occurring motor proteins that walk along cellular highways known as microtubules, carrying along varied molecular cargo for distribution inside the cell.

The hydrogel-aptamer system neatly sorted thrombin molecules from a protein-rich solution also containing transferrin, an iron-binding plasma glycoprotein and bovine serum albumin. Thrombin molecules were transported from the upper solution of the microfluidic device to the lower solution, where they were released. (As anticipated, control experiments in which the thrombin-binding aptamer was either missing or mismatched failed to recover detectable amounts of thrombin.)

The new technique offers a significant advance over conventional methods of sorting biomolecules, which typically involve molecular modification, numerous experimental steps and energy input from external sources. Further, the new system is highly adaptive to different situations, permitting fine-grained control during continuous separation.

The reversible nature of the capture, transport and release system allows for multiple recycling of biomolecules and high rates of target recovery. The use of complementary responsive materials permits the system to be custom designed to meet a broad range of needs.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
Arizona State University
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Rare-earth innovation to improve nylon manufacturing
Ames IA (SPX) Apr 01, 2015
The Critical Materials Institute, a U.S. Department of Energy Innovation Hub led by the Ames Laboratory, has created a new chemical process that makes use of the widely available rare-earth metal cerium to improve the manufacture of nylon. The process uses a cerium-based material made into nanometer-sized particles with a palladium catalyst to produce cyclohexanone, a key ingredient in the ... read more


TECH SPACE
Extent of Moon's giant volcanic eruption is revealed

Yutu Changes Everything We Thought We Knew About Our Moon

Extent of moon's giant volcanic eruption is revealed

NASA's LRO Spacecraft Finds March 17, 2013 Impact Crater and More

TECH SPACE
Rover Amnesia Event Follows Latest Memory Reformatting

Ancient Martian lake system records 2 water-related events

Curiosity Rover Finds Biologically Useful Nitrogen on Mars

NASA's Opportunity Mars Rover Passes Marathon Distance

TECH SPACE
NASA Announces New Partnerships with Industry for Deep-Space Skills

A Year in Space

Russia to Consider Training First Guatemalan Cosmonaut

Russia, US to Jointly Prepare Mars, Moon Flight Road Map

TECH SPACE
Chinese scientists mull power station in space

China completes second test on new carrier rocket's power system

China's Yutu rover reveals Moon's "complex" geological history

China's Space Laboratory Still Cloaked

TECH SPACE
Cosmonauts Take Tablet Computer Into Space

Russia announces plan to build new space station with NASA

Soyuz spacecraft docks at ISS for year-long mission

One-Year Crew Set for Launch to Space Station

TECH SPACE
Soyuz Installed at Baikonur, Expected to Launch Wednesday

Soyuz ready March 27 flight to deploy two Galileo navsats

UAE Moves to Purchase Russian Spacecraft Launch Platform

Russia Launches Satan Missile With S Korean Kompsat 3A Satellite

TECH SPACE
Earthlike 'Star Wars' Tatooines may be common

Planets in the habitable zone around most stars, calculate researchers

Our Solar System May Have Once Harbored Super-Earths

SOFIA Finds Missing Link Between Supernovae and Planet Formation

TECH SPACE
Study reveals novel technique for handling molecules

Twisted nanofibers create structures tougher than bulletproof vests

A method to simplify pictures makes chemistry calculations a snap

Metals used in high-tech products face future supply risks




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.