Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Using chemistry to predict the dynamics of clotting in human blood

18.10.2006
Microfluidics technique could find medical-diagnostic applications

University of Chicago chemists have demonstrated for the first time how to use a simple laboratory model consisting of only a few chemical reactions to predict when and where blood clotting will occur. The scientists used microfluidics, a technique that allowed them to probe blood clotting on surfaces that mimic vascular damage on the micron scale, a unit of measurement much narrower than the diameter of a human hair.

Although scientists understand what occurs during many of the 80 individual chemical reactions involved in blood clotting, many questions about the dynamics of the entire reaction network remain. Rustem Ismagilov, Associate Professor in Chemistry at the University of Chicago, and graduate students Christian Kastrup, Matthew Runyon and Feng Shen have now developed a technique that will enable scientists to understand the rules governing complex biological reaction networks. They will detail their technique in the online early edition of the Oct. 16-20 issue of the Proceedings of the National Academy of Sciences.

Life and death literally depend on a finely tuned blood-clotting system. "Clotting has to occur at the right place at the right time," Ismagilov said. "A strong, rapid clotting response is essential to stop bleeding at a wound, but such a clotting response at the wrong spot can block blood vessels and can be life-threatening."

In the past, scientists have typically examined the blood-clotting network using flasks containing homogenous mixtures-the test fluids were the same throughout. But the contents of the circulatory system are not homogeneous, said Kastrup, a Ph.D. student in chemistry and the PNAS article's lead author. One of the great virtues of microfluidics technology is its ability to control complex reactions at critical times and locations.

"The blood-clotting system contains both fluids and surfaces in an elaborate spatial environment, where localization of chemicals is very important," he said. Microfluidic technology can address this issue through its ability to control complex reactions at critical times and locations.

In previous work, the Ismagilov group designed a simple laboratory model to simulate blood clotting. In this model, Ph.D. student Runyon and his associates devised three modules that correspond to the three major stages of clotting: production of chemicals that activate clotting, the inhibition of these activators, and formation of the solid clot.

In this model, the scientists used only one chemical reaction in each module instead of the 20-to-30 biochemical reactions that the modules represent. Surprisingly, this simple model adequately reproduced many features of blood clotting.

"There's a long history in chemistry of using simple models to understand more complex behavior," Kastrup said. "Instead of looking at hundreds of equations for blood clotting, we reduced it down to three main equations. From these equations we were able to describe a lot of the dynamics of clotting."

The ability of microfluidics to mimic the flow and geometry of human blood vessels also proved critical.

"We had to use microfluidics to do all of this because that's how we controlled where everything is," Ismagilov said of Runyon's previous work. "It turned out that we got appropriate behavior only if we used geometry similar to those observed in our vascular system. If we changed the geometry to something that didn't look like a biological system, the chemical system couldn't function. So geometry and flow were very important."

In the latest advance, Kastrup used Runyon's model to see if he could predict when clotting would occur in human blood. The team predicted and verified that clotting occurs only at locations of vascular damage larger than a critical size. "Surprisingly, this simple model made correct, quantitative predictions about blood clotting," Kastrup said.

Furthermore, the model provided new details about the dynamics of clotting. A big question in blood-clotting studies is the role of a protein called tissue factor. Can tissue factor exist in blood without the presence of clotting?

"From our experiments we see that it's not the overall concentration of tissue factor that matters, but it's the localization of it that makes a difference," Kastrup explained. That means a high concentration of tissue factor at one location will result in clotting, while the same number of molecules spread farther apart will not.

In the future, chemists might now be able to apply microfluidics to the study of other complex reaction networks that control various biological functions. And in the medical arena, the technique could become a way to perform rapid and detailed diagnostic tests. "We'd love to see that happen," Kastrup said.

Steve Koppes | EurekAlert!
Further information:
http://www.uchicago.edu

Further reports about: CHEMISTRY Complex Dynamics Ismagilov Kastrup blood-clotting clotting microfluidics reaction

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>