The holy grail of treating neuronal injuries is to persuade damaged neurones to regrow exactly as they were. Currently doctors lack the tools to do this, but hope is in sight in the world of nanotechnology.
Unfortunately, once nerves have suffered damage they don’t simply grow back to their original position. There are a number of reasons for this:
- Inflammation gets in the way
- Molecules found primarily in the mature nervous system inhibit growth
- Gaps formed in nervous tissue caused by the “cleaning up” of injured cells form a barrier to growing cells
- Cells fail to start regrowing
But how can nanotechnology help?
Nanotechnology is the science of the very small (on the scale of billionths of a millimetre) but it’s an enormous area of research – in many countries nanoscience is the priority for science budgeters.
Successful attempts have now been made to use nanotubules as a type of molecular scaffolding to support nerve growth. A nanotubule is a tiny (on the nanometer scale) tube-like structure – like a microscopic drinking straw. The first application of these tubes showed that, when coated with substances that encourage neuronal growth, carbon nanotubles were able to promote extension of rat embryonic nerve cells. These tiny tubes acted as a physical scaffold to guide the cells, while also providing chemical signals ‘telling’ them to grow and survive.
Nanotubes made of amino acids (the building blocks of proteins) have also been developed. These amino acids can interact directly with receptors on nerve cell membranes and have proved effective at encouraging growth and limiting the damaging effects of scar tissue. Because these are composed of naturally-occurring amino acids they are not toxic to cells and caused no inflammation or immune response in animals. This is a serious benefit, as inflammation can be very damaging in neuronal injury.
However, the unique features of nanomaterials could also be associated with unique problems. At high concentrations, some studies have found nanotubes of certain sizes to cause DNA damage, accumulation and inflammation in the lungs. Another concern is that nanoparticles can move around the body: one study showed that nanoparticles could be transmitted up nerves and into the brain. Nanotechnology may represent an exciting opportunity in medical science, but it also comes with the major challenge of understanding how the behaviour of these materials interacts with the human body.
Post by: Claire Scofield