A metal key that switches on chemotherapy only inside the tumour

Chemotherapy's cruelty is its aim: the drugs poison dividing cells everywhere, not just the cancer. A University of Basel team led by Dr Thomas Ward has built a molecular delivery trick — an iridium catalyst, a metal-based helper, fitted with a homing piece that latches onto a protein found on tumour cells. The catalyst travels with an inactive, 'caged' version of a cancer drug and performs a chemical reaction — a Buchner ring expansion — that uncages the drug only where the catalyst has docked: at the cancer. Published in the Journal of the American Chemical Society, the work is early, cell-stage science, but it sketches a future where the active drug exists only in the one place it is needed.

SDG 3 · Good health and well-being — Mechanism: tech innovation