Nanotech and stem cells meet and marry. Will heaven bless the union?

Nanofibres made of self-assembling peptides may help promote neuron regeneration in spinal cord injuries

By Owen Dyer

We've been hearing for years about how nanotechnology, the next big thing in the realm of the very small, will one day revolutionize medicine. Another miracle treatment that seems to recede endlessly into the horizon is stem cells. It now appears that one could be key to making the other work.

A neurologist and a materials scientist at Northwestern University have pooled their talents to come up with a gel that contains not only stem cells but also microscopic scaffolding for them to grow on. They claim that, injected into damaged spinal cord tissue, it could prevent the scarring that's often linked to paralysis after spinal cord injury. Their findings are published in the current issue of the journal Science.

The secret is nanofibres formed by peptide amphiphile molecules that self-assemble into a scaffold on injection. The scientists' key breakthrough was designing the peptide amphiphiles so that when they self-assemble, a specific sequence of five amino acids known to promote neuron growth is presented on the outer surfaces.

"We have shown that our scaffold selectively and rapidly directs cell differentiation, driving neural progenitor cells to become neurons and not astrocytes," said Samuel Strupp, professor of Materials Science and Engineering, who led the research team. "Astrocytes are a major problem in spinal cord injury because they lead to scarring and act as a barrier to neuron repair."

The team believes the technique could also have applications for neural regeneration in the brain. Mr Strupp is collaborating with John Kessler, professor of Neurology at Northwestern's Feinberg School of Medicine. Dr Kessler took on the project after his daughter was paralysed in a skiing accident in 2001.

The researchers are now planning to start tests on rats and mice. They believe the gel could be ready for applications in humans in "more than two, but less than 10 years."