Tumor targeting can be achieved through various mechanisms:
1. Passive Targeting: Exploits the EPR effect where nanoparticles naturally accumulate in tumor tissues due to their leaky vasculature and poor lymphatic drainage. 2. Active Targeting: Involves functionalizing nanoparticles with molecules that specifically bind to receptors overexpressed on cancer cells, such as folic acid, antibodies, or aptamers. 3. Stimuli-responsive Targeting: Nanoparticles can be designed to respond to specific stimuli present in the tumor microenvironment, such as pH, temperature, or enzymes, triggering the release of therapeutic agents.
