You won't be able to catch your supper with this fishing rod -- because at just 6mm long, it's designed to catch and kill cancers before they aggressively attack the brain.
Created from a length of polymer lined with 10 micrometre-thick film that mimics the shape of nerves and blood vessels, the rods trick glioblastoma cancer cells into hitching a ride aboard them. The cancer cells usually latch onto blood vessels and nerves to spread, but they're equally attracted to these synthetic rods that can be (fairly) easily implanted in the brain.
At the top end of the rod is a small deposit of gel containing drugs that kill glioblastoma. As New Scientist explains, the idea is that "tumour cells mistake the rod for a nerve or blood vessel, travel up it and meet their death at the end." In experiments in rats, the device was incredibly successful, with the majority of tumour cells migrating up the rod, and residual tumours tending to shrink by almost 90 per cent.
Sadly, the technique would never rid a patient of cancer entirely, but it could be used to manage or shrink inoperable tumors, buying sufferers months -- or even years -- more life. And that's quite a catch. [Nature Materials via New Scientist]