Physical and Biological Targeting

Abstract

This chapter describes the concept of physical and biological targeting. Physical targeting consists of a series of physical techniques to enhance drug delivery, such as electroporation, magnetofection, ultrasound, photochemical internalization, and hypothermia. Biological targeting strategies can be divided in passive and active targeting.Passive targeting refers to the exploitation of the natural (passive) distribution pattern of a drug carrier in vivo. This phenomenon is based upon the process named “enhanced permeability and retention (EPR)” effect. The active approach relies upon the selective localization of a ligand at a cell-specific receptor. In this chapter we describe the advantages of macromolecular support in the design of drug delivery systems and various applications of active pargeting especially in the treatment of cancer.

Keywords: Magic bullet, selective toxicity, physical targeting, biological targeting, electroporation, magnetofection, ultrrasound, cavitation, photochemical internalization-PCI, photosensitizers, lectins, micelles, tetrapeptide, HPMA, hyperthermia, enhanced permeability and retention-EPR effect, clathrin, integrin, passive targeting, active targeting.