Polymer nanoparticles have played a central role in several recent scientific breakthroughs and are major components in several newly emerging technologies, ranging from self-healing coatings to drug delivery systems and imaging techniques. Hitherto, in such applications (e.g. in therapeutic applications) the polymer nanoparticles have to exhibit complex properties: to be stable, biocompatible, targeted to a specific location, physically and chemically compatible with their cargo, and responsive, so that the cargo can be released when required. There is a compelling need to go beyond simple structures to meet these challenges. This research aims to develop hierarchical polymer nanoparticles and 3D structures with tailored composition, functionalities and controlled responsiveness. These novel hierarchical structures will comprise individual domains/shells with different properties to furnish different functionalities for, e.g., targeted delivery of drug molecules.