Polymeric amphiphiles derived from hydrophobically modified soluble polymers are able to spontaneously form micelles or nanoparticles via undergoing intra- and/or intermolecular association between hydrophobic moieties in aqueous environment. These polymeric nanoparticles exhibit unique characteristics, such as special rheological features, a rather narrow size distribution, considerable lower critical aggregation concentrations (CAC) than low molecular weight surfactant, and thermodynamic stability. Recently, self-assembled nanoparticles based on natural polysaccharides have been of particular interest because of their good biocompatibility, biodegradability, reduced toxic side effects and improved therapeutic effects. Kwon et al.prepared hydrophobically modified glycol chitosan by covalent attachment of 5β-cholanic acid to glycol chitosan which form self-assemble nanoparticles in a water solution.