Nanomedicine uses nanotechnology (tiny particles called nanoparticles, and machines called nanorobots) to improve drug delivery to specifically targeted organs. Targeting specific organs allows doctors to achieve the best possible effectiveness and safety of the drugs they administer. The size of the nanoparticle, which usually ranges from 1 to 100 nm (nano- means "billionth part of"), as well as its shape and surface chemistry all affect what the body does to a drug, including
Most nanomedicines are administered orally or intravenously and achieve their effects through accumulation throughout certain tissues, including tumors.
Nanoparticles are designed to stay in targeted organs for long periods of time and cause the fewest side effects.
(See also Introduction to Administration and Kinetics of Drugs.)