Nanoparticles at work: High‐contrast tumorimaging of mice was performed by usingcopolymers with hydrophobic and hydrophilic polymer brushes that form cross‐linked assemblies and show a highly stable core surface in aqueous media (see picture). Cyclic RGD peptides and glucosamine moieties were localized on the surface of the assemblies and acted as targeting agents (TA) that enhanced the accumulation