ACTIVE TARGETING WITH PARTICULATE CARRIER SYSTEMS IN THE BLOOD COMPARTMENT

This review deals with active targeting of particulate drug carriers through (1) physico-chemical (e.g., complex formation between a homing device and a surface exposed molecule at the target site) and (2) physical means, Target sites discussed are restricted to those in the blood circulation. Targets for particulate systems using homing devices (physico-chemical approach) are circulating cells and non-cellular material, e.g., red blood cells, T-lymphocytes, B-lymphocytes, and drugs, respectively. Fixed cells and non-cellular material have also been subject of investigation (e.g., endothelial cells and thrombi, respectively), Active targeting in the above areas has been mainly performed with liposomes as carrier systems and monoclonal antibodies or antibody fragments as homing devices. Less literature is available on physical targeting approaches in the blood compartment such as targeting through magnetic field gradients, local hyperthermia or artificial embolus formation.