Nanoparticles prepared by self-assembly of Chitosan and poly-γ-glutamic acid

The present paper describes the preparation and characterization of novel biodegradable nanoparticles based on self-assembly of poly-gamma-glutamic acid (gamma-PGA) and chitosan (CH). The nanosystems were stable in aqueous media at low pH conditions. Solubility of the systems was determined by turbidity measurements. Surface charge and mobility were measured electrophoretically. The particle size and the size distribution of the polyelectrolyte complexes were identified by dynamic light scattering and transmission electron microscopy (TEM). It was found that the size and size distribution of the nanosystems depends on the concentrations of gamma-PGA and CH solutions and their ratio as well as on the pH of the mixture and the order of addition. The diameter of individual particles was in the range of 20-285 nm measured by TEM, and the average hydrodynamic diameters were between 150 and 330 nm. These biodegradable, self-assembling stable nanocomplexes might be useful for several biomedical applications.