Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bones at the nanoscale - Scientists see with X-rays how bones resist strain thanks to their nano and micro structure

08.11.2006
Scientists from Max Planck Institute (Germany) and the ESRF have just discovered the way deformation at the nanoscale takes place in a bone by studying it with the synchrotron X-rays. This study explains the enormous stability and deformability of bones. The hierarchical structure of bones makes them able to sustain large strains without breaking, despite being made of essentially rigid units at the molecular level. The results are published this week in the PNAS early online edition.

A bone is made up of two different elements: half of it is a stretchable fibrous protein called collagen and the other half a brittle mineral phase called apatite. These components make this biomineralized tissue highly strong and tough. at the same time, In order to understand how this construction is achieved and functions, scientists from the Max Planck Institute of Colloids and Interfaces in Potsdam (Germany) came to the ESRF. Using X-rays they were able to see for the first time the simultaneous re-arrangement of organic and inorganic components at a micro and nanoscale level under tensile stress.


The hierarchical structure of bone gives rise to a hierarchical deformation via a staggered load transfer mechanism at the nanoscale. The yellow cylinders denote the mineralized collagen fibrils in longitudinal section, and the red tablets denote the mineral apatite crystallites embedded within the collageneous matrix of the fibrils. The strain decreases from the tissue (left) to mineral particle level (right) in a ratio of approximately 12:5:2. Credits: Himadri Gupta/Max Planck Institute of Colloids and Interfaces.

The scientists realised that when strain/pressure is applied to a bone, this is absorbed by soft layers at successively lower length scales, and less than a fifth of the strain is actually noticed in the mineral phase. The soft structures form a single rigid unit at the next level and so on, enabling the tissue to sustain large strains. This is why the brittle apatite remains shielded from excessive loads and does not break.

The results also showed that the mineral crystallites are nonetheless very strong, capable of carrying more than 2 – 3 times the fracture load of bulk apatite. Their small size preserves them from large cracks. This is the first experimental evidence for this effect in biomaterials – small particles resist failure better.

Scientists carried out experiments on ID2 beamline at the ESRF. They tracked the molecular and supramolecular rearrangements in bone while they applied stress using the techniques of X-ray scattering and diffraction in real time. The high brilliance of the X-ray source enabled the tracking of bone deformation in real time. Researchers could look at two length scales: on one side they observed the 100 nanometers sized fibres, and on the other, the crystallites embedded inside the fibre, which are not bigger than 2 to 4 nanometers. The critical sample preparation was developed by Max Planck researchers, which made it possible to isolate tissue in bone of about 100-200 microns of size.

These results provide new insight in the design principles which make healthy bone so fracture resistant. The research may contribute to medical as well as technological developments: “The outcome of this research may contribute to a future development of bio-inspired and new nanocomposite materials. On a medical level, it may help to understand how a molecular level change can make whole bones more prone to fracture in diseases like osteoporosis”, explains Himadri Gupta, first author of the paper. Further ongoing research aims at telling us how these design principles differ in bones with different mechanical function and how they may be affected by age and disease.

Montserrat Capellas | alfa
Further information:
http://www.esrf.fr/news/pressreleases/bones/

More articles from Physics and Astronomy:

nachricht Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials
17.01.2018 | Universität des Saarlandes

nachricht Black hole spin cranks-up radio volume
15.01.2018 | National Institutes of Natural Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>