"Our self-assembling peptide nanofibre scaffold created a good environment not only for axons to regenerate through the site of an acute injury, but also to knit the brain tissue together," said Shuguang Zhang of MIT.

Zhang and colleagues injected a solution of the peptides into the animals' brains. The fibres then self-assembled into a network in the void in the animal's brain caused by injury. The technique could ultimately help people who have suffered traumatic brain injuries, spinal cord injuries and stroke.

"If we can reconnect parts of the brain that were disconnected by a stroke, then we may be able to restore speech to an individual who is able to understand what is said but has lost the ability to speak," said Rutledge Ellis-Behnke of MIT. "This is not about restoring 100% of damaged brain cells, but 20% or even less may be enough to restore function."

The nanofibre scaffold consists of peptide nanofibres around 10 nm in diameter. The fibres form a network that is similar in scale to the surrounding matrix. The researchers believe that the presence of the network promotes cell migration into the region, which creates a "growth-permissive environment".

After about six weeks, three quarters of the treated hamsters would turn towards a sunflower seed in their field of vision, although they responded 29% slower than normal animals.

The fibres break down into amino acids that are found in the body naturally, and are excreted by the kidneys within 3–4 weeks. What's more, the fibres do not cause an inflammatory response.

The team is now testing the technique on spinal cord injuries and hopes to launch trials in primates and eventually in humans.

The researchers reported their work in PNAS.