  Engineered nanoparticles made from noble metals, rare-earth oxides or
semiconductors are emerging as the central constituents of future nanotech
developments. In this review, a survey of the complexing strategies between
nanoparticles and oppositely charged polyelectrolytes developed during the last
three years and based on electrostatic interactions is presented. These
strategies include the one-step synthesis of stable and functionalized
nanoparticles, the one- and multilayer coating of individual nano-objects, the
controlled clustering of particles and the generation of capsules and thin
films with superior functionalities. Among the formulation processes reported,
three main classes are identified : the direct mixing route, the desalting
transition pathway and the well-known layer by layer method. Finally, some
latter developments, trends and applications of electrostatic assemblies in
materials science and nanomedicine are highlighted
