Featured Research

from universities, journals, and other organizations

Scientists Probe Bones' Tiny Building Blocks

Date:
May 26, 2007
Source:
Massachusetts Institute of Technology
Summary:
In work that could lead to more effective diagnoses and treatments of bone diseases using only a pinhead-sized sample of a patient's bone, MIT researchers report a first-of-its-kind analysis of bone's mechanical properties.

MIT researchers created this nanoscale map of the stiffness of bone.
Credit: Image courtesy / Ortiz Lab, MIT

In work that could lead to more effective diagnoses and treatments of bone diseases using only a pinhead-sized sample of a patient's bone, MIT researchers report a first-of-its-kind analysis of bone's mechanical properties.

Related Articles


The work, reported in the May 21 advance online edition of Nature Materials, sheds new light on how bone absorbs energy.

The researchers' up-close-and-personal look at bone probes its fundamental building block--a corkscrew-shaped protein called collagen embedded with tiny nanoparticles of mineral--at the level of tens of nanometers, or billionths of a meter. A human hair, by comparison, is 80,000 nanometers in diameter.

"If you want to investigate the origins of the strength and toughness of a material, you probe it at smaller and smaller length scales," said co-author Subra Suresh, Ford Professor of Engineering, with appointments in materials science and engineering, biological engineering, mechanical engineering and the Harvard-MIT Division of Health Sciences and Technology. "The methodologies used in this research can be employed to assess the quality of bone with extremely high precision by providing new and detailed structural and mechanical information on the nature of its fundamental constituents."

The insights gained from the work could also lead to the creation of new, tougher materials, he said.

The study was led by Christine Ortiz, associate professor of materials science and engineering. "The structure, quality and integrity of bone change dramatically with age and disease, hence understanding the origins of the mechanical properties of this major load-bearing, structural tissue in our body is extremely important from a medical standpoint," Ortiz said.

Using a table-top instrument called a molecular force probe, which uses an extremely small probe tip to poke out a tiny fragment of bone, Ortiz and colleagues mapped the stiffness of bovine shin bone into complex, colorful, two-dimensional contour maps similar to those used by geographers.

The team found that the mechanical properties of bone vary greatly within a single region only two micrometers (thousandths of a meter) wide. Because a variety of disorders tied to disease or aging lead to changes in bone structure, the researchers' discovery of the non-uniformity of bone's mechanical properties at very small length scales could lead to improved diagnoses of diseases. For example, if specific nanoscale patterns of stiffness within bone structure are tied to disease or aging, these could potentially be identified earlier or provide more conclusive evidence of a disorder.

The researchers also formulated a computer model to study the effects of their experimental results on larger-scale biomechanical properties. For example, using the model they found that the non-uniform stiffness patterns were advantageous to bone's ability to absorb energy.

"We tend to think that if a material is non-uniform, it is not as tough," Suresh said. "This work shows otherwise. Our thesis is that nature, by making bones non-uniform at extremely small length scales over the course of millions of years of evolution, has designed bone to be able to absorb much more energy than a uniform material with the same properties."

"I was surprised that we observed such beautiful and complex patterns," Ortiz said. "Cells sense and respond to stresses in their environment. Since different local mechanical properties in bone change the magnitude of stresses around the cell, the cells' behavior can be altered in response, thereby affecting the health of the tissue."

In addition, the team's results could lead to new ways of producing improved structural composites that mimic nature's clever design that allows bones to resist sudden fractures; to "fail gracefully," as Suresh put it. For example, certain kinds of a new class of materials called nanocomposites are composed of a polymer or metallic matrix filled with nanoscale particles randomly distributed or periodically spaced. "There may be ways to disperse particles non-uniformly that may lead to improved material toughness," Suresh said.

Ortiz' and Suresh's colleagues on the work are Kuangshin Tai, a recent MIT Ph.D. graduate; research scientist Ming Dao of the Department of Materials Science and Engineering; and Ahmet Palazoglu of the University of California at Davis.

Ortiz is currently looking at stem-cell-based, tissue-engineered bone in collaboration with Dan Gazit at the Hebrew University of Jerusalem to see how similar it is to native bone. She is also applying the new analysis and related imaging and simulation techniques to different types of mineralized biological materials such as armored scales from ancient fish and seashells.

This work was supported by the Whitaker Foundation, the U.S. Army Research Office, the MIT Institute for Soldier Nanotechnologies and the National Institutes of Health.


Story Source:

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


Cite This Page:

Massachusetts Institute of Technology. "Scientists Probe Bones' Tiny Building Blocks." ScienceDaily. ScienceDaily, 26 May 2007. <www.sciencedaily.com/releases/2007/05/070524172342.htm>.
Massachusetts Institute of Technology. (2007, May 26). Scientists Probe Bones' Tiny Building Blocks. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2007/05/070524172342.htm
Massachusetts Institute of Technology. "Scientists Probe Bones' Tiny Building Blocks." ScienceDaily. www.sciencedaily.com/releases/2007/05/070524172342.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Blu-Ray Discs Getting Second Run As Solar Panels

Blu-Ray Discs Getting Second Run As Solar Panels

Newsy (Nov. 26, 2014) Researchers at Northwestern University are repurposing Blu-ray movies for better solar panel technology thanks to the discs' internal structures. Video provided by Newsy
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. 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


Space & Time

Matter & Energy

Computers & Math

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