Tiny flecks of gold could be used in the fight against cancer, new research has suggested.
Scientists at Edinburgh University found the precious metal increased the effectiveness of drugs used to treat lung cancer cells.
Minute fragments, known as gold nanoparticles, were encased in a chemical by the research team.
The research involved zebrafish but the team are hopeful the technique could be used to develop human treatments.
Gold is a safe element which can accelerate - or catalyse - chemical reactions.
It is hoped such a method could one day be used to reduce side effects of current chemotherapy treatments by precisely targeting diseased cells without damaging healthy tissue.
Dr Asier Unciti-Broceta, from Cancer Research UK's Edinburgh centre, said: "We have discovered new properties of gold that were previously unknown and our findings suggest that the metal could be used to release drugs inside tumours very safely.
"There is still work to do before we can use this on patients, but this study is a step forward. We hope that a similar device in humans could one day be implanted by surgeons to activate chemotherapy directly in tumours and reduce harmful effects to healthy organs."
Dr Aine McCarthy, Cancer Research UK's senior science information officer, said: "By developing new, better ways of delivering cancer drugs, studies like this have the potential to improve cancer treatment and reduce side effects.
"In particular, it could help improve treatment for brain tumours and other hard-to-treat cancers. The next steps will be to see if this method is safe to use in people, what its long and short-term side effects are, and if it's a better way to treat some cancers."
The study was carried out in collaboration with researchers at the University of Zaragoza's Institute of Nanoscience of Aragon in Spain and published in the scientific journal Angewandte Chemie.