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Those nano bones...are made for walking!
Velocity   
Tuesday, 27 October 2009
bone.jpg
The 'nano bone' may be more easily accepted
by the body than traditional titatium.
Image: iStockphoto

And that's just what they're going to do! As we get older our joints wear out and every year 50,000 Australians end up with metal hip or knee implants but now thanks to scientists we will be able to have replacements that look and behave like real bone.

At Murdoch University in Perth, scientists have created a material that closely mimics the structure and composition of real bone which they are calling "nano-bone" which has the potential to revolutionise joint replacement surgery making artificial titanium implants a thing of the past.

Each year artificial implants, mostly made of titanium metal, are inserted into hips and knees. One of the risks associated with joint implants is the possibility of infection.

Murdoch scientist, Dr Gérrard Poinern, has created a new formulation of the mineral powder made of the main component of bone - a ceramic called hydroxyapatite (HAP).

"Hydroxyapatite is chemically similar to the mineral component of bones and hard tissues in mammals which gives bones their strength," he said.

"The 'nano-bone' material could potentially replace the traditional titanium joint with a nano-bone plate that is more widely accepted by the body.

"Nano-bone implants have better capacity to interact with living tissue, allowing the body to repair itself much faster as it recognises similar nano material and tries to grow into it," Gérrard said.

"The powder is created using nanotechnology, in which we work with sub-microscopic molecules to solve some of the world's biggest problems.

"We know bone is made up of little rods of hydroxyapatite so we have manufactured a new version of HAP that can be shaped into any form, including current implant designs. What's really exciting is that because it's a powder it can be shaped into screws, plates and any other shape required.

"And on top of that it also opens the way for us to experiment with combining this nano-bone with other substances at the nano-scale to maybe increase strength or produce other novel attributes.

"Nano-bone may also be dosed with antibiotics which are released when bacteria enter the site of the joint replacement improving the chances of the implant being accepted by the body," he said.

President of the Australian Orthopaedic Association John Batten told the Sunday Times in Perth that the science behind creating nano-bone was new, but it could become a great tool for orthopaedic surgeons.

"It has great potential for prosthesis, for implants and for fracture healing and other things we do to the skeleton," he said.

To create the nano-bone for the implants, Gerard's team worked with millions of spheres just 37 nanometres long. One nanometre is one millionth of a millimetre. A human hair is 80,000 nanometres wide.

The Murdoch Applied Nanotechnology Research Group (MANRG) combined chemicals such as calcium nitrate, ammonium hydroxide and potassium hydrogen phosphate, which when heated under ultrasound waves formed tiny mineral spheres.

While nanotechnology offers an infinite way to improve the world - from making space-flight more practical to improvements in medicine, food and technology – the implications of controlling matter at an atomic level is much debated.

Concerns about toxicity, environmental and health impacts as well as the effect of nanotechnologies on global economics have sparked doomsday predications.

Everyday products from car parts to sunscreens already contain nano-particles and advocacy groups such as Friends of the Earth are calling for better government regulation of the new technology.

Gerard said his nano-bone was still a few years from being implanted in anyone.

"Part of the journey ahead is to figure out its applications and to work with partners in the medical device industry and surgeons to assess what exciting new products could be manufactured," he concluded.


Editor's Note: A story provided by Velocity - Science in Motion.  This article is under copyright; permission must be sought from Velocity to reproduce it.
 
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