Chitosan/poly-γ-glutamic acid nanoparticles improve the solubility of lutein

Abstract

The aim of this study was to improve the solubility of lutein through the use of chitosan (CS)/poly-γ-glutamic acid (γ-PGA) nanoencapsulation. In terms of redispersibility, water-soluble chitosan (WsCS)/γ-PGA nanoparticles (NPs) were better than insoluble chitosan (InCS)/γ-PGA NPs. The lutein-loaded WsCS/γ-PGA NP has a spherical form with a size around 200 nm and a narrow size distribution (PDI < 0.1). Solubility measures showed that nanoencapsulation of lutein into WsCS/γ-PGA NPs resulted in a significant 12-fold higher solubility compared to that of non-nanoencapsulated lutein (p < 0.05). The redispersibility index of the lutein-loaded NPs was 1.01, indicating that they were completely reconstituted into aqueous solution as same as original aqueous solution. These results suggest that WsCS/γ-PGA nanoencapsulation can be used to enhance the solubility of lutein and other poorly water-soluble compounds.