How Doctors Are Harnessing the Power of Gold to Fight Cancer | Innovation | Smithsonian

Oncologists are now injecting cancer patients with ultra-tiny, gold-wrapped spheres. The nano­particles, each smaller than a red blood cell, accumulate in a tumor after slipping out of the bloodstream through little holes in the tumor’s rapidly growing vessels. Once there, the gold waits—until an oncologist blasts it with near-infrared light.