Figure 1.

Schematic representation of the role of enhanced permeability and retention effect (EPR) in the delivery of drug carriers.

Notes: Tumor targeting of both targeted and nontargeted nanoparticles is achieved by extravasation of nanoparticles through increased permeability of the tumor vasculature and ineffective lymphatic drainage (EPR), whereas ligand-targeted nanoparticles could recognize, bind, and enter the tumor cells via receptor-mediated internalization.