Back when I was in High School I read Engines of Creation by K. Eric Drexler. The book describes the potential of nanotechnology -- a technology that would involve the use of molecular sized machines in fields as diverse as manufacturing, medicine, and space travel. Since its original publication date in the late 1980s numerous advances have been made. A recent exciting advance is described here:
Researchers from the Nano Machine Center at the California NanoSystems Institute at UCLA have developed a new nanomachine that can capture and store anticancer drugs. The tiny nano machines are called “nanoimpellers” and store anticancer medications inside tiny pores and release the drugs directly into cancer cells in response to light.This a truly amazing achievement with great potential for the future.