Active targeting drug delivery nanocarriers: Ligands

There are two kinds of targeted drug delivery systems: (I) Active targeted drug delivery (smart drug delivery) based on ligands affiliation to receptors, (II) Passive targeted drug delivery, based on the enhanced permeability and retention effect (EPR effect). Active targeted drug delivery system is based on a method that delivers a certain amount of a therapeutic or diagnostic agent or both of them to a targeted diseased area within the special organ in the body. Drug-loaded nanoparticles (NPs) by the addition of ligands or with special physical or chemical engineering at structure are used for recognition by specific receptors/antigens on target cells for limitations of non-specific distribution of drug in whole cells of body and decreasing cytotoxicity and side effects of drugs on healthy cells and organs that it is impossible in traditional chemotherapy. Smart nanoparticles vehicles have been approved for the treatment of a broad spectrum of human cancers.