Transporter-mediated tissue targeting of therapeutic molecules in drug discovery

Tissue concentrations of endogenous chemicals and nutrients are in large part regulated by membrane transporters through their substrate specificity and differential tissue distributions. These transporters also play a key role in the disposition of therapeutic agents thus affecting their efficacy and safety profile. A transporter-mediated tissue targeting strategy, where the structural features recognized by the transporters are incorporated into the therapeutic molecule, is emerging as an effective approach in drug discovery. In this digest, we review this phenomenon and highlight recent cases in the design of liver and kidney targeted drug molecules.