ABSTRACT
The severe toxic side effects associated with the administration of the anticancer drug doxorubicin makes this drug an ideal candidate for tumor-targeted delivery. To achieve tumor targeting, doxorubicin is often encapsulated into pharmaceutical nanocarriers, such as liposomes. The use of liposomes as anticancer drug delivery systems was originally hampered by their fast removal from the blood; however, liposome longevity in the body was achieved by coating of its surface with polyethylene glycol. Doxorubicinloaded long-circulating liposomes underwent a successful transfer from the bench to the clinic and demonstrated good properties based on their ability to passively accumulate in the tumor via the enhanced permeability and retention effect. Still, it is believed that the active targeting of drug-loaded liposomes to tumor with the
use of liposome-attached tumor-specifi c ligand can improve their therapeutic potential furthermore. Among a variety of methods employed to target liposomal anticancer drugs to tumors, the most successful results were achieved using antibody-mediated (immuno) targeting. Various schemes for attaching antibodies and their fragments on the surface of liposomes, either directly or via distal coupling or functionalized polymeric liposome coatings are well elaborated and characterized.
