The researchers at Georgia Tech have initially focused on cancerous brain tumours. They said that one of the factors which makes such cancers hard to treat successfully is that the malignant cells spread throughout the brain by following nerve fibres and blood vessels to invade new locations.
“We have designed a polymer thin-film nanofibre that mimics the structure of nerves and blood vessels that brain tumour cells normally use to invade other parts of the brain,” said Ravi Bellamkonda, the lead investigator. “The cancer cells normally latch onto these natural structures and ride them like a monorail to other parts of the brain. By providing an attractive alternative fibre, we can efficiently move the tumours along a different path to a destination that we choose.”
The scientists put their polycaprolactone (PCL) fibres, which are half the diameter of a human hair, into the brains of rats in which a human tumour was growing.
The fibres led the migrating cancer cells to a “tumour collector” gel which contained a drug which is toxic to cancer cells. They also put ordinary fibres into other rats and left a number of others untreated.
After 18 days, the researchers found that compared to other rats, tumour sizes were substantially reduced in animals that had received the PCL nanofibre implants near the tumours. Tumour cells had moved the entire length of all fibres into the collector gel outside the brain.
While eradicating a cancer would always be the ideal treatment, Ravi Bellamkonda said the new technique might be able to control the growth of inoperable cancers, allowing patients to live normal lives despite the disease. “If we can provide cancer an escape valve of these fibres, that may provide a way of maintaining slow-growing tumours such that, while they may be inoperable, people could live with the cancers because they are not growing.”