Featured Research

from universities, journals, and other organizations

Tissue engineers use new system to measure biomaterials, structures

Date:
April 12, 2011
Source:
Brown University
Summary:
As cells assemble into a donut shape and ascend a hydrogel cone, they do work and thereby reveal the total power involved in forming a three-dimensional structure. That measure not only could help tissue engineers understand their living building materials better, but could also add insight to the understanding of natural tissue formation.

Climbing higher, higher Cells forming themselves into a doughnut-shaped tissue appear to climb a hydrogel cone. Researchers can calculate the energy expended by the cells in overcoming gravity.
Credit: Morgan Lab/Brown University

Tissue engineering makes biologists builders, but compared to their civil engineering counterparts, they don't know much about the properties of the materials and structures they use, namely living cells. To improve that knowledge, Brown University researchers have developed a simple and reliable system for measuring the power that cells employ to assemble into three-dimensional tissue.

Related Articles


The research appears online in the Proceedings of the National Academy of Sciences.

In addition to helping engineers evaluate how quickly and stably different cell types will combine into desired structures, the power measurements could also improve scientists' understanding of natural tissue growth, such as in fetal development, and how cancerous cells sometimes break off from a tumor and travel in the body, said Jeffrey Morgan, the paper's senior author and associate professor of medical science in Brown's Department of Molecular Pharmacology, Physiology and Biotechnology.

"Cells are the ultimate building parts, and it's important to understand how they are held together, how they assemble together and the energies with which they do that, if you want to delve into the field of tissue engineering," said Morgan, who last year co-developed the first artificial human ovary. "Sometimes these complex processes go wrong, and that's where it's relevant to cancer in terms of cell-to-cell adhesion. But it also plays out very nicely in developmental biology where a very complex 3-D orchestration of cell movement and forces gives rise to new tissues and organs."

Climb the cone

In the system, the researchers deposited cells in very small wells made of a specially designed hydrogel. The wells each have a cone of different steepness rising in the middle, like Bundt cake pans do. The cells form a doughnut shape around the cone. The mutual attraction of the cells then causes the doughnut of living cells to slide up the cone while a video microscope watches. The observed rate at which this mass of cells overcomes the force of gravity to ascend the cone yields a valuable number for the overall power exerted by the cells.

"There's no need to calibrate this device, because gravity is consistent and reliable and there are no moving parts other than the living cells," Morgan said.

Such overall measures of energy, time, and power have been hard to obtain, said lead author and doctoral candidate Jacquelyn Youssef. Many scientists have studied distinct forces and energies within and among cells, such as the bonding strength between particular proteins, but such measures leave tissue engineers to estimate the total energy in a structure by adding up what's known about the cells, related proteins, and their many interactions.

"What we've developed looks at all these things in this one system together," Youssef said. "There's lots of moving parts."

At the same time as it offers an aggregate measure, the system allows for teasing out the relative contributions of those moving parts. In their experiments, the team, which also included Lambert Freund, professor emeritus of engineering at Brown, and recent Ph.D. graduate Asha Nurse, used a drug treatment to inhibit the contractions cells use to "grab" each other. They found that among human skin fibroblast cells, eliminating that particular action took away about half of the total power of the doughnut structure formation.

The researchers worked with two types of cells in the paper. In addition to human skin fibroblasts, which aggregated and ascended the cones in a couple of hours, they also tested liver cells, which took days to reach the same peaks.

Morgan said the system will work for many other cell types and even mixtures of cells as well, making it a promising instrument for assessing the structural characteristics of the variety of building materials that tissue engineers might choose to use in their structures. Bioengineers can also use it to measure the effect different chemicals or drugs might have on the rate or energy of tissue formation.

"What we're driving at is an understanding of how cells will spontaneously form these three-dimensional structures," Morgan said. "The rate at which they do that is important to understanding how to design something more complex."

Funding for the research came from the National Science Foundation and the National Institutes of Health.


Story Source:

The above story is based on materials provided by Brown University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jacquelyn Youssef, Asha K. Nurse, L. B. Freund, Jeffrey R. Morgan. Quantification of the forces driving self-assembly of three-dimensional microtissues. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1102559108

Cite This Page:

Brown University. "Tissue engineers use new system to measure biomaterials, structures." ScienceDaily. ScienceDaily, 12 April 2011. <www.sciencedaily.com/releases/2011/04/110411152520.htm>.
Brown University. (2011, April 12). Tissue engineers use new system to measure biomaterials, structures. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2011/04/110411152520.htm
Brown University. "Tissue engineers use new system to measure biomaterials, structures." ScienceDaily. www.sciencedaily.com/releases/2011/04/110411152520.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Hugging It Out Could Help You Ward Off A Cold

Hugging It Out Could Help You Ward Off A Cold

Newsy (Dec. 21, 2014) Carnegie Mellon researchers found frequent hugs can help people avoid stress-related illnesses. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins