Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Magnetic nano-'shepherds' organize cells

02.04.2009
The power of magnetism may address a major problem facing bioengineers as they try to create new tissue -- getting human cells to not only form structures, but to stimulate the growth of blood vessels to nourish that growth.

A multidisciplinary team of investigators from Duke University, Case Western Reserve University and the University of Massachusetts, Amherst created an environment where magnetic particles suspended within a specialized solution act like molecular sheep dogs.

In response to external magnetic fields, the shepherds nudge free-floating human cells to form chains which could potentially be integrated into approaches for creating human tissues and organs.

The cells not only naturally adhere to each other upon contact, the researchers said, but the aligned cellular configurations may promote or accelerate the creation and growth of tiny blood vessels.

"We have developed an exciting way of using magnetism to manipulate human cells floating freely in a solution containing magnetic nanoparticles" said Randall Erb, fourth-year graduate student in the laboratory of Benjamin Yellen, assistant professor of Mechanical Engineering and Materials Science, at Duke University's Pratt School of Engineering. "This new cell assembly process holds much promise for tissue engineering research and offers a novel way to organize cells in an inexpensive, easily accessible way."

Melissa Krebs, third-year biomedical engineering graduate student at Case Western and Erb's sister, co-authored a paper appearing online in advance of the May publication of Nano Letters, a journal published by the American Chemical Society.

"The cells have receptors on their surfaces that have an affinity for other cells," Krebs said. "They become sticky and attach to each other. When endothelial cells get together in a linear fashion, as they did in our experiments, it may help them to organize into tiny tubules."

The iron-containing nanoparticles used by the researchers are suspended within a liquid known as a ferrofluid. One of the unique properties of these ferrofluids is that they become highly magnetized in the presence of external magnetism, which allows researchers to readily manipulate the chain formation by altering the strength of the magnetic field.

At the end of the process, the nanoparticles are simply washed away, leaving a linear chain of cells. That the cells remain alive, healthy and relatively unaltered without any harmful effects from the process is one of the major advances of the new approach over other strategies using magnetism.

"Others have tried using magnetic particles either within or on the surface of the cells," Erb said. "However, the iron in the nanoparticles can be toxic to cells. Also, the process of removing the nanoparticles afterward can be harmful to the cell and its function."

The key ingredient for these studies was the synthesis of non-toxic ferrofluids by colleagues Bappaditya Samanta and Vincent Rotello at the University of Massachusetts, who developed a method for coating the magnetic nanoparticles with bovine serum albumin (BSA), a protein derived from cow blood. BSA is a stable protein used in many experiments because it is biochemically inert. In these experiments, the BSA shielded the cells from the toxic iron.

"The other main benefit of our approach is that we are creating three-dimensional cell chains without any sophisticated techniques or equipment," Krebs said. "Any type of tissue we'd ultimately want to engineer will have to be three-dimensional."

For their experiments, the researchers used human umbilical vein endothelial cells. Others types of cells have also been used, and it appears to the researchers that this new approach can work with any type of cell.

"While still in the early stages, we have shown that we can form oriented cellular structures," said Eben Alsberg, assistant professor of Biomedical Engineering and Orthopedic Surgery at Case Western and senior author of the paper. "The next step is to see if the spatial arrangement of these cells in three dimensions will promote vascular formation. A major hurdle in tissue engineering has been vascularization, and we hope that this technology may help to address the problem."

Richard Merritt | EurekAlert!
Further information:
http://www.duke.edu

More articles from Physics and Astronomy:

nachricht NASA mission surfs through waves in space to understand space weather
25.07.2017 | NASA/Goddard Space Flight Center

nachricht A new level of magnetic saturation
25.07.2017 | Georg-August-Universität Göttingen

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>