Because of their structural and dynamical properties, microheterogeneous systems have been employed as solvent and reaction media both to synthesize and stabilize nanoparticles. Following this route, inside their nanometer-sized heterogeneities the nanoparticles of many different substances have been incorporated. The book shows the distinct advantages of this synthetic strategy over that of many other methods. Moreover, it furnishes to the reader a collection of theoretical and experimental facts allowing him to reduce the number of trial and errors necessary to arrive at an optimal synthetic protocol.