There are two primary types of targeting mechanisms in nanotechnology:
1. Passive Targeting Passive targeting exploits the natural characteristics of nanoparticles and their interactions with biological systems. The Enhanced Permeability and Retention (EPR) effect is a key example. Tumor tissues have leaky vasculature and poor lymphatic drainage, which allow nanoparticles to accumulate more in these areas than in normal tissues.
2. Active Targeting Active targeting involves functionalizing nanoparticles with ligands that bind specifically to receptors on the target cells. This can significantly enhance the selectivity and uptake of the nanoparticles by the target cells.
