Featured Research

from universities, journals, and other organizations

Bioengineers Develop Microfabricated Device To Measure Cellular Forces During Tissue Development

Date:
July 7, 2009
Source:
University of Pennsylvania
Summary:
Scientists studying the physical forces generated by cells has created a tiny micron--sized device that measures and manipulates cellular forces as assemblies of living cells reorganize themselves into tissues.

Immunofluorescence sections of cells embedded within a micropatterned collagen gel. Cells generate forces within a tissue that can feedback to regulate the accumulation of cytoskeletal proteins such as actin (green) and structural matrix proteins such as fibronectin or tenascin C (red) in a spatially dependent manner. Cell nuclei are labeled in blue.
Credit: Image courtesy of Wesley R Legant

A University of Pennsylvania-collaboration of bioengineers studying the physical forces generated by individual cells has created a tiny micron–sized device that allows researchers to measure and manipulate cellular forces as assemblies of living cells reorganize themselves into tissues.

The new micro-tool created in the study allows researchers to gauge how cells' minute mechanical forces affect cellular behavior, protein deposition and cell differentiation in a 3-dimensional, in vivo-like environment that mimics how tissue actually forms in a living organism. The finding also has implications for the testing of irregular or diseased tissue, such as beating cardiac tissue, which can be modeled and studied.

The findings were published in June in the Proceedings of the National Academy of Sciences.

The push-and-pull of cellular forces drives the buckling, extension and contraction of cells that occur during tissue development. These processes that ultimately shape the architecture of tissues play an important role in coordinating cell signaling, gene expression and behavior, and they are essential for wound healing and tissue homeostasis in adult organisms.

Yet a detailed picture of how tissue mechanics link to morphogenetic phenomena has been hindered by a lack of model systems in which both mechanics and remodeling can be simultaneously examined.

The Penn study highlights a complex and dynamic relationship between cellular forces, visualizes the remodeling of a matrix by living cells and demonstrates a system to study and apply this relationship within engineered 3-D microtissue.

Chris Chen, professor of bioengineering in the School of Engineering and Applied Science at Penn, developed the tool with colleagues at the University of California, Santa Barbara, and the University of Cambridge.

The system was created using photolithography, the same technology used to craft semiconductors. Scientists fabricated an array of tiny divots within a mold and immersed the mold in a culture of cells and collagen. Researchers then placed raised microcantilever posts on either side of the mold and — much like draping a volleyball net across two metal poles -- observed the formation of a cell and collagen web of living tissue anchored to the cantilevers. These microcantilevers were used to simultaneously constrain the remodeling of a collagen gel and to report forces generated during this process.

The cantilever posts allowed the team to observe and measure the retraction and extension of the cells as they remodeled the adjacent matrix into a coherent band of tissue. Varying the mechanical stiffness of the cantilevers and collagen matrix demonstrated that the cellular forces increased with boundary or matrix rigidity, whereas the levels of proteins in the cytoskeleton and extracellular matrix also increased with levels of mechanical stress. By mapping these relationships between cellular and matrix mechanics, cellular forces and protein expression onto a bio-chemo-mechanical model of microtissue contractility, the team demonstrated how intratissue gradients of mechanical stress can emerge from collective cellular contractility and, finally, how such gradients can be used to engineer protein composition and organization within a 3-D tissue.

"Just as we build muscle in the gym, these same mechanical forces are translated down to the cellular level and build the complex arrangement of different tissues in the body," co-author Wesley Legant said. "By varying the properties of our model system, we can study how these mechanical factors are distributed throughout a tissue and how this can, in turn, effect cellular function."

"With this system, we also see the potential for high-throughput drug testing, as researchers will be able to test new pharmaceuticals against a vast array of these small tissue samples, perhaps identifying new ways to increase the contractility of cardiac muscle, or to relax arteries to treat hypertension," said Chen, the study's lead author.

Working with colleagues, the team also created a mathematical model of the entire process that accurately predicted the experimental results.

"With this model, we can extend our findings to more complex and realistic model tissues which might be difficult to study experimentally in the lab" Legant said.

The study was conducted by Chen, Legant and Michael T. Yang of the Department of Bioengineering at Penn; Amit Pathak and Robert M. McMeeking of the Department of Mechanical Engineering at UCSB; and Vikram S. Deshpande of the Department of Engineering at Cambridge.

The research was funded by grants from the National Institutes of Health, an Army Research Office Multidisciplinary University Research Initiative, the Material Research Science and Engineering Center and Center for Engineering Cells and Regeneration at Penn, the U.S Department of Education's Graduate Assistance in Areas of National Need and the National Science Foundation's Graduate Research Fellowship.


Story Source:

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


Cite This Page:

University of Pennsylvania. "Bioengineers Develop Microfabricated Device To Measure Cellular Forces During Tissue Development." ScienceDaily. ScienceDaily, 7 July 2009. <www.sciencedaily.com/releases/2009/06/090622171514.htm>.
University of Pennsylvania. (2009, July 7). Bioengineers Develop Microfabricated Device To Measure Cellular Forces During Tissue Development. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2009/06/090622171514.htm
University of Pennsylvania. "Bioengineers Develop Microfabricated Device To Measure Cellular Forces During Tissue Development." ScienceDaily. www.sciencedaily.com/releases/2009/06/090622171514.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Flamingo Frenzy Ahead of Zoo Construction

Flamingo Frenzy Ahead of Zoo Construction

AP (Apr. 17, 2014) With plenty of honking, flapping, and fluttering, more than three dozen Caribbean flamingos at Zoo Miami were rounded up today as the iconic exhibit was closed for renovations. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. 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:
from the past week

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