Effect of sophorolipid on the curcumin-loaded ternary composite nanoparticles self-assembled from zein and chondroitin sulfate

Abstract The curcumin (Cur) loaded ternary self-assembly composite nanoparticles consisting of zein, chondroitin sulfate (CS) and sophorolipid (Spl) were designed successfully with zein-to-Spl mass ratio of 1:1 (Cur-Z/CS/SplNPs1:1), showing nano-spherical structure with high ζ-potential and encapsulation efficiency. The encapsulation process converted Cur from crystal to amorphous nature, involving electrostatic force, hydrophobic interaction and hydrogen bonding. Spl improved the resistance of zein to degeneration with or without Cur and CS. Cur-Z/CS/SplNPs1:1 showed stability at pH > 4.0 and the better thermostability (80 °C) at a faster rate. Additionally, Cur showed the best chemical stability in Cur-Z/CS/SplNPs1:1 under the condition of 4 °C in the dark with half-life of 58.74. And Cur-Z/CS/SplNPs1:1 enhanced the aqueous solubility of Cur about 160 times higher than that of free Cur in powder state. Furthermore, Cur-Z/CS/SplNPs1:1 exhibited the biocompatibility, bioaccessibility (68.06%) and anticancer activity against HepG2, MCF-7 and HeLa cells. This study provides new insights into the application of Spl in protein/polysaccharide delivery systems in the food, pharmaceutical and cosmetic industries.