Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

With optical ’tweezers,’ researchers pinpoint the rhythmic rigidity of cell skeletons

04.12.2003


Laser tool makes it possible to study the interior of an endothelial cell in a non-invasive way



Endothelial cells, which line the body’s blood vessels and regulate the exchange of material between the blood stream and surrounding tissue, are one of the most closely studied types of cell in the body.

The cells play an important role in cardiovascular disease. And a greater knowledge of their interior functions may help scientists develop new cancer treatments that curb or suppress the growth of tumors by cutting off their blood supply.


Daniel Ou-Yang’s research group at Lehigh University is the first to use a laser tool known as optical tweezers to study the interior of an endothelial cell in a non-invasive way without introducing foreign particles into the cell or around it.

Achieving a resolution of 0.5 microns, Ou-Yang and his group can pinpoint and "trap" an organelle - a specialized part of a cell that resembles and functions like an organ - without damaging it.

They have discovered that the rigidity of the cytoskeleton, or cell skeleton, in the vicinity of the cell’s organelles, appears to change by a factor of four in a rhythmical pattern with a periodicity of 20 to 30 seconds.

"This rhythm tells us something is alive," says Ou-Yang, a professor of physics, co-director of Lehigh’s bioengineering program and a member of Lehigh’s Center for Optical Technologies. "But it raises other questions. What triggers this rhythm? And what is its significance?"

Ou-Yang is collaborating with Linda Lowe-Krentz, professor of biological sciences. He also works with Profs. Ivan Biaggio and Volkmar Dierolf of the physics department and the COT, who specialize in the advanced imaging techniques necessary to measure the intracellular molecular signals.

Dierolf incorporates Raman spectroscopy scattering to see molecules without labeling (dyeing) them. Biaggio measure the mechanical properties of cells using nonlinear optical effects, which generate ultrasound waves to measure mechanical properties.

The work of Ou-Yang, Biaggio and Dierolf is supported by the COT. Ou-Yang and Lowe-Krentz are seeking a grant from the National Science Foundation.

Ou-Yang’s group also includes several students. Meron Mengistu is a graduate student in molecular biology. Elizabeth Rickter, a graduate student in physics, was the first person to observe the rhythmic behaviors that appear to originate from endothelial cytoskeletons. And Laura Morkowchuk, a sophomore bioengineering major, is studying the effect of the cytoskeletal rhythm on the transport of proteins from the blood stream to a cell’s interior substrate tissues.

The overall goal of Ou-Yang’s group is to understand the mechanisms and functions of a cell in a quantitative way, and to map cell functions as scientists have already mapped such major body functions as respiration and digestion.

Ou-Yang has used optical tweezers in his research for more than 10 years, and is one of the pioneers in the technique. The tweezers, also called laser tweezers or optical traps, focus a laser beam through an optical microscope to trap micron-sized dielectric objects, which can then be manipulated by externally steering the laser beams.

Optical tweezers can pinpoint organelles at a resolution of 0.5 microns. The resulting vibration of the cell part is 0.5 nanometers, a measurement that Ou-Yang’s group makes with an innovative application of optical diffraction.

The researchers are interested in cytoskeletal rigidity for several reasons. The cytoskeleton plays an important role in cell division. If scientists can learn how to suppress the rearrangement of the cytoskeleton that is necessary for mitosis to occur, they might be able to obstruct the growth of cancerous tumors, which depends on the often runaway rate of mitosis in cancerous cells.

Cytoskeletal rigidity has also been observed as a response to the chemical treatments used on cancer patients, Ou-Yang says. And tumor growth can be choked by depriving cancer cells of their blood supply, which is regulated by endothelial cells.

Two other Lehigh students have contributed to Ou-Yang’s work with laser tweezers. Larry Hough, who received his Ph.D. in physics in August, is now a research scientist at the University of Pennsylvania. Megan Valentine, earned a B.S. in physics from Lehigh in 1996, recently completed a Ph.D. in physics at Harvard, and is going to Stanford to become a research scientist in biophysics.

Kurt Pfitzer | EurekAlert!
Further information:
http://www.lehigh.edu/

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

LZH showcases laser material processing of tomorrow at the LASYS 2018

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>