Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bioengineers: Matrix stiffness is an essential tool in stem cell differentiation

11.08.2014

Bioengineers at the University of California, San Diego have proven that when it comes to guiding stem cells into a specific cell type, the stiffness of the extracellular matrix used to culture them really does matter.

When placed in a dish of a very stiff material, or hydrogel, most stem cells become bone-like cells. By comparison, soft materials tend to steer stem cells into soft tissues such as neurons and fat cells.


Cells grown on hydrogels of the same stiffness all display fat cell markers and deform the underlying matrix material the same way.

Credit: Adam Engler, UC San Diego Jacobs School of Engineering


Cells grown on three hydrogels of the same stiffness all display fat cell markers and deform the underlying matrix material in the same way.

Credit: Adam Engler, UC San Diego Jacobs School of Engineering

The research team, led by bioengineering professor Adam Engler, also found that a protein binding the stem cell to the hydrogel is not a factor in the differentiation of the stem cell as previously suggested. The protein layer is merely an adhesive, the team reported Aug. 10 in the advance online edition of the journal Nature Materials.

Their findings affirm Engler's prior work on the relationship between matrix stiffness and stem cell differentiations.

"What's remarkable is that you can see that the cells have made the first decisions to become bone cells, with just this one cue. That's why this is important for tissue engineering," said Engler, a professor at the UC San Diego Jacobs School of Engineering.

Engler's team, which includes bioengineering graduate student researchers Ludovic Vincent and Jessica Wen, found that the stem cell differentiation is a response to the mechanical deformation of the hydrogel from the force exerted by the cell.

In a series of experiments, the team found that this happens whether the protein tethering the cell to the matrix is tight, loose or nonexistent. To illustrate the concept, Vincent described the pores in the matrix as holes in a sponge covered with ropes of protein fibers.

Imagine that a rope is draped over a number of these holes, tethered loosely with only a few anchors or tightly with many anchors. Across multiple samples using a stiff matrix, while varying the degree of tethering, the researchers found no difference in the rate at which stem cells showed signs of turning into bone-like cells.

The team also found that the size of the pores in the matrix also had no effect on the differentiation of the stem cells as long as the stiffness of the hydrogel remained the same.

"We made the stiffness the same and changed how the protein is presented to the cells (by varying the size of the pores and tethering) and ask whether or not the cells change their behavior," Vincent said. "Do they respond only to the stiffness? Neither the tethering nor the pore size changed the cells."

"We're only giving them one cue out of dozens that are important in stem cell differentiation," said Engler. "That doesn't mean the other cues are irrelevant; they may still push the cells into a specific cell type. We have just ruled out porosity and tethering, and further emphasized stiffness in this process."

###

The paper is "Interplay of matrix stiffness and protein tethering in stem cell differentiation," by Jessica H. Wen, Ludovic G. Vincent, Alexander Fuhrmann, Yu Suk Choi, Kolin Hribar, Hermes Taylor-Weiner, Shaochen Chen and Adam J. Engler in the Departments of Bioengineering and NanoEngineering at UC San Diego Jacobs School of Engineering. Engler is also a researcher at the Sanford Consortium for Regenerative Medicine. His work is partially funded by the National Institutes of Health (DP02D006460).

Catherine Hockmuth | Eurek Alert!

Further reports about: Bioengineers Engineering Matrix bone cells fat cells hydrogel materials pores stem cells stiff stiffness

More articles from Life Sciences:

nachricht Identifying drug targets for leukaemia
02.05.2016 | The Hong Kong Polytechnic University

nachricht A cell senses its own curves: New research from the MBL Whitman Center
29.04.2016 | Marine Biological Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: 2+1 is Not Always 3 - In the microworld unity is not always strength

If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”

In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...

Im Focus: Tiny microbots that can clean up water

Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.

Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...

Im Focus: ORNL researchers discover new state of water molecule

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...

Im Focus: Bionic Lightweight Design researchers of the Alfred Wegener Institute at Hannover Messe 2016

Honeycomb structures as the basic building block for industrial applications presented using holo pyramid

Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...

Im Focus: New world record for fullerene-free polymer solar cells

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The “AC21 International Forum 2016” is About to Begin

27.04.2016 | Event News

Soft switching combines efficiency and improved electro-magnetic compatibility

15.04.2016 | Event News

Grid-Supportive Buildings Give Boost to Renewable Energy Integration

12.04.2016 | Event News

 
Latest News

Identifying drug targets for leukaemia

02.05.2016 | Life Sciences

Clay nanotube-biopolymer composite scaffolds for tissue engineering

02.05.2016 | Materials Sciences

NASA's Fermi Telescope helps link cosmic neutrino to blazar blast

02.05.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>