EPR Effect vs Active Ligand Targeting

This simulator compares two nanoparticle-delivery strategies inside a single vascular scene split between healthy tissue and a tumor. Passive, EPR-only nanoparticles leak through abnormally leaky tumor vessel walls simply by circulating in the blood — the enhanced permeability and retention effect — while ligand-coated, actively-targeted nanoparticles leak through the same gaps and then go one step further, seeking out and binding receptors that cancer cells overexpress. Live counters track how many particles of each type sit in healthy tissue, sit loosely in tumor tissue, or have actually been internalized inside cancer cells, making the size-dependence of EPR and the added value of active targeting directly visible.