Fabrication and characterization of zein nanoparticles by dextran sulfate coating as vehicles for delivery of curcumin.

Zein nanoparticles (ZNPs) have limited use as a result of its poor colloidal stability. The goal of this paper is to stabilize ZNPs using a sulfated anionic polysaccharide-dextran sulfate (DS). Zein/DS composite nanoparticles (ZDSNPs) were fabricated by antisolvent precipitation method at pH 4.0 with an optimal zein-to-DS ratio of 1:2 (w/w). ZDSNPs exhibited good stability to pH, heating and storage. Additionally, ZDSNPs showed spherical structures formed primarily by electrostatic attractions, hydrogen bonding and hydrophobic interactions. The incorporation of DS led to the change in secondary structure of zein. The surface hydrophobicity of ZNPs reduced owing to the deposition of DS. And ZDSNPs were basically nontoxic to normal colonic epithelial cell lines-NCM460 cell lines. ZDSNPs were successfully used to encapsulate curcumin. The encapsulation efficiency of curcumin-loaded ZDSNPs (ZDSCNPs) was 85.37%, which was significantly higher than that of curcumin-loaded ZNPs. In addition, ZDSCNPs exhibited improved storage stability and bioaccessibility of curcumin.