March 14, 2006
|Nanotech Induces Nerve Repair In Hamsters||Science/Technology|
This is an amazing story, the stuff of sci-fi. And no doubt it's just the beginning. Since nanotech is progressing at an exponential rate, we're all going to be surprised as applications like this seem to appear out of nowhere. Our children are going to grow up in a very different world. BBC:
Nanotechnology has restored the sight of blind rodents, a new study shows.
Scientists mimicked the effect of a traumatic brain injury by severing the optical nerve tract in hamsters, causing the animals to lose vision.
After injecting the hamsters with a solution containing nanoparticles, the nerves re-grew and sight returned. [...]
Repairing nerve damage in the central nervous system after injury is seen as the ultimate challenge for neuroscientists, but so far success in this field has been limited.
Nerve regeneration is set back by a number of factors, including scar tissue and gaps in brain tissue caused by the damage. And this can make treatment by medical and surgical methods very difficult.
To find a novel way around these problems, the team based at Massachusetts Institute of Technology (MIT), US, and Hong Kong University looked towards nanotechnology — a branch of science involving the manipulation of atoms and molecules.
The researchers injected the blind hamsters at the site of their injury with a solution containing synthetically made peptides — miniscule molecules measuring just five nanometres long.
Once inside the hamster's brain, the peptides spontaneously arranged into a scaffold-like criss-cross of nanofibres, which bridged the gap between the severed nerves.
The scientists discovered that brain tissue in the hamsters knitted together across the molecular scaffold, while also preventing scar tissue from forming.
Importantly, the newly formed brain tissue enabled the brain nerves to re-grow, restoring vision in the injured hamsters.
"We made a cut, put the material in, and then we looked at the brain over different time points," explained Dr Rutledge Ellis-Behnke, a neuroscientist at MIT and lead author on the paper.
"The first thing we saw was that the brain had started to heal itself in the first 24 hours. We had never seen that before — so that was very surprising."
The scientists looked at young hamsters with actively growing nerve cells, and also at adult hamsters whose nerves had stopped growing.
Dr Ellis-Behnke said the team was surprised to find that the nerves in the adult hamsters had re-grown after the injection.
"We found that we had got functional return of vision and orientating behaviour, which was very surprising to us because we thought we would have to promote cell growth, through the growth factors."
The researchers found the peptides were later broken down by the body into a harmless substance and excreted in the animals' urine three to four week after first injected. [...]
"Eventually what we would look at is trying to reconnect disconnected parts of the brain during stroke and trauma."
Dr Ellis-Behnke said that stroke and traumatic brain injury could have a major impact on an individual.
"In order to try to restore quality of life to those individuals you can try to reconnect some disconnected parts to try to give some functionality in the brain for communication and other things like that. And that's where we think that this might be very useful," he added. [Emphasis added]
An especially interesting thing about this story is the way the technique blends biology and nanotech. The molecules that were introduced (molecules that were constructed using nanotech methods) were essentially biological molecules — peptides, which are basically pieces of protein. They were molecules that the body knows how to interact with and how to break down and excrete. They did their job, and then they were gone without a trace. Fantastic stuff.
Knowledge of the details of biology at the molecular scale is increasing at an exponential rate, and so is the technical ability to construct synthetic molecules. Put those two things together, as in the technique described above, and the possibilities truly are staggering. We ain't seen nothing yet.