Nanoparticle Drug Targeting: EPR & Receptor Binding

This simulator models how a nanoparticle drug carrier reaches a tumor: it circulates through a 3D blood vessel, leaks preferentially through the abnormally leaky tumor microvasculature (the enhanced permeability and retention, or EPR, effect) while being size-excluded by tight healthy vessel walls, and — once inside the tumor — binds tumor-cell receptors according to ligand-receptor (Langmuir) binding kinetics. Adjust particle size, surface ligand density and tumor receptor density to see how passive size-exclusion and active receptor targeting combine to determine what fraction of a dose ends up on-target versus in healthy tissue.