Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Shaping up: Controlling a stem cell's form can determine its fate

14.09.2011
"Form follows function!" was the credo of early 20th century architects making design choices based on the intended use of the structure.

Cell biologists may be turning that on its head. New research* by a team working at the National Institute of Standards and Technology (NIST) reinforces the idea that stem cells can be induced to develop into specific types of cells solely by controlling their shape. The results may be important to the design of materials to induce the regeneration of lost or damaged tissues in the body.


Bone-like cell growth on nanofibers: confocal microscope images detail the growth of a human bone marrow stromal cell (actin filaments in the cell "skeleton" are stained orange) on a nanofiber scaffold (green). The structure of thin fibers encourages stem cells to develop into the elongated, branched form characteristic of mature bone cells. Credit: Tison, Simon/NIST

Tissue engineering seeks to repair or re-grow damaged body tissues, often using some form of stem cells. Stem cells are basic repair units in the body that have the ability to develop into any of several different forms. The NIST experiments looked at primary human bone marrow stromal cells, adult stem cells that can be isolated from bone marrow and can "differentiate" into bone, fat or cartilage cells, depending.

"Depending on what?" is one of the key questions in tissue engineering. How do you ensure that the stem cells turn into the type you need? Chemical cues have been known to work in cases where researchers have identified the proper additives—a hormone in the case of bone cells. Other research has suggested that cell differentiation on flat surfaces can be controlled by patterning the surface to restrict the locations where growing cells can attach themselves.

The experiments at NIST are believed to be the first head-to-head comparison of five popular tissue scaffold designs to examine the effect of architecture alone on bone marrow cells without adding any biochemical supplements other than cell growth medium. The scaffolds, made of a biocompatible polymer, are meant to provide a temporary implant that gives cells a firm structure on which to grow and ultimately rebuild tissue. The experiment included structures made by leaching and foaming processes (resulting in microscopic structures looking like clumps of insect-eaten lettuce), freeform fabrication (like microscopic rods stacked in a crisscross pattern) and electrospun nanofibers (a random nest of thin fibers). Bone marrow stromal cells were cultured on each, then analyzed to see which were most effective at creating deposits of calcium—a telltale of bone cell activity. Microarray analysis also was used to determine patterns of gene expression for the cultured cells.

The results show that the stem cells will differentiate quite efficiently on the nanofiber scaffolds—even without any hormone additives—but not so on the other architectures. The distinction, says NIST biologist Carl Simon, Jr., seems to be shape. Mature bone cells are characteristically long and stringy with several extended branches. Of the five different scaffolds, only the nanofiber one, in effect, forces the cells to a similar shape, long and branched, as they try to find anchor points. Being in the shape of a bone cell seems to induce the cells to activate the genes that ultimately produce bone tissue.

"This suggests that a good strategy to design future scaffolds would be to take into account what shape you want to put the cells in," says Simon, adding, "That's kind of a tall order though, you'd have to understand a lot of stuff: how cell morphology influences cell behavior, and then how the three-dimensional structure can be used to control it." Despite the research still to be done on this method, the ability to physically direct cell differentiation by shape alone potentially would be simpler, cheaper and possibly safer than using biochemical supplements, he says.

The work was supported in part by the National Institute of Dental and Craniofacial Research, National Institutes of Health.

* G. Kumar, C.K. Tison, K. Chatterjee, P.S. Pine, J.H. McDaniel, M.L. Salit, M.F. Young and C.G. Simon, Jr. The determination of stem cell fate by 3D scaffold structures through the control of cell shape. Biomaterials (2011), doi:10.1016/j.biomaterials.2011.08.054.

Michael Baum | EurekAlert!
Further information:
http://www.nist.gov

More articles from Life Sciences:

nachricht New catalyst controls activation of a carbon-hydrogen bond
21.11.2017 | Emory Health Sciences

nachricht The main switch
21.11.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>