PEGylation Stealth Shield: Opsonin Adsorption vs. Polymer Brush Density

This simulator renders a drug-delivery nanoparticle coated in a real polyethylene-glycol (PEG) brush and lets you tune the two parameters that actually control its "stealth" behaviour in blood — grafting density and chain length. Alexander–de Gennes brush theory converts those into a brush height and a mushroom-vs-brush regime live on screen, while a population of instanced opsonin proteins diffuses toward the surface, each one testing a steric-shielding adsorption probability derived from that same brush height. Proteins that stick build a visible corona; once coverage crosses a recognition threshold, a macrophage sweeps in and clears the particle, and the whole cycle's rate is read out as an estimated circulation half-life — showing directly why denser, longer PEG coatings mean nanoparticles survive longer in the bloodstream.