Smart orthopaedic devices:
There is an ever increasing aging population which means that more and more of us are facing orthopaedic surgery. One of the most commonly procedures is hip replacement. Implants currently used often fail due to various reasons, but one of the most common causes is the loss of integration between the implant and the bone. To date, orthopaedic companies have tried to get an interlocking effect by roughening the surface by sandblasting. However, roughening the surface produces a random surface texture which cannot be exactly reproduced from implant to implant. Also, research has shown that sandblasted surfaces may have a negative effect on the bone cells.
In Glasgow, we have developed a technology whereby we can make tiny holes (100 nanometre in diameter, that is 0.0001 mm) in a surface. We are using semiconductor technology to make 1 billion (1.000.000.000) of these holes in one square centimetre.
We have discovered that when the holes are arranged in a specific pattern we can encourage adult stem cells from bone marrow to develop into bone producing cells resulting in mineral production. This means that the cell will make bone directly on the implant surface. This is a substantial improvement over current techniques where cement is used to hold the implant in place.
To understand exactly how the cells respond and develop on such engineered surfaces we look at their genome regulation. Through the use of microarrays printed with many-thousands of known genes (which encode for proteins) we can assess cell functionality, considering the whole genome, very rapidly. This is an important step towards next generation of smart orthopaedic implants using nanotechnology.
Data & SEMs: Dr. Nikolaj Gadegaard & Dr. Matthew Dalby, Centre for Cell Engineering, Glasgow University.
© 2007 M. Robertson/Nanovisions
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