http://nano.cancer.gov/

Nanotechnology—the science and engineering of controlling matter, at the molecular scale, to create devices with novel chemical, physical and/or biological properties—has the potential to radically change how we diagnose and treat cancer. Although scientists and engineers have only recently (ca. 1980's) developed the ability to industrialize technologies at this scale, there has been good progress in translating nano-based cancer therapies and diagnostics into the clinic and many more are in development.