Tumor Interstitial Pressure: The EPR Penetration Barrier

Nanoparticle drugs are famous for slipping through the leaky, disorganized blood vessels that feed a tumor — the "enhanced permeability" half of the EPR effect. This simulator shows what happens after that leak: the elevated, nearly flat interstitial fluid pressure inside a tumor kills the convective push that would otherwise carry drug deep into the tissue, so particles that cross the vessel wall often stall in a thin perivascular shell instead of reaching cells further away. Adjust the baseline interstitial pressure, tissue hydraulic conductivity and particle size to watch the radial pressure profile, the convective velocity field, and the resulting penetration depth respond in real time, driven by the same Baxter–Jain pressure model and Stokes–Einstein diffusion used in tumor-transport pharmacology.