We have developed versatile routes to nanogel core, multiarm stars and polymeric unimolecular amphiphiles that provide exquisite control over molecular size, polydispersity, chain and peripheral functionality etc. The number of arms is adjustable from 20 to more than 100. The synthetic route is cheap and scalable and purification is simple providing an intrinsic advantage over dendrimers. These materials readily encapsulate a variety of hydrophobic materials at reasonable loading levels (10-15%) without covalent binding. The cores and arms can be bio- stable, -degradable or -compatible. In addition to small molecules, nanoparticles including superparamagnetic materials can be encapsulated in the outer shell through ligand-mediated binding. The outer shell and periphery can also catalyze the controlled deposition of various inorganic shells including organosilicates and gold. The nanoparticles are multicompartmental and are useful as dual function reagents for therapeutics and imaging.