Drug targeting with nanoparticles.

Nanoparticles are colloidal polymeric particles (size < 1000 nm) to which drugs are bound by sorption, incorporation, or chemical binding. After intravenous injection they normally distribute into the organs of the reticuloendothelial system (liver, spleen, lungs, bone marrow). However, their body distribution can be altered by coating with surfactants or with physiological components such as serum complement factors. The influence of these coatings on the body distribution and possible mechanisms for the alteration of this distribution are discussed. Differently coated nanoparticles can be used for the targeting of bound drugs to tumors, to the brain, and to inflamed areas in the body.