Polysaccharide-based nanoparticles fabricated from oppositely charged curdlan derivatives for curcumin encapsulation

In this study, carboxylic curdlan (Cur-48) and negatively charged ferulic acid (FA)-grafted carboxylic curdlan (Cur-48-g-FA) were separately used to fabricate polyelectrolyte nanoparticles (PNPs: PNPs-CQ and PNPs-CFQ) with positively charged quaternized curdlan (Qcurd) for curcumin delivery. Results showed that curcumin-loaded PNPs-CQ and PNPs-CFQ had particle sizes of 338.1 and 301.3 nm, zeta potentials of -19.07 and -24.10 mV, and encapsulation efficiencies of 76.32% and 83.54%, respectively. Curcumin was properly encapsulated inside the two PNPs through electrostatic interactions and hydrogen bonds. Compared with free curcumin, entrapped curcumin in the two PNPs exhibited better redispersion performance, thermo- and photostability, and sustained release property. Furthermore, FA molecules surrounding the surface of PNPs-CFQ were conductive to the entrapped curcumin's particulate characteristics, stability, release behavior, and antioxidant potentials. Therefore, our findings indicated that PNPs formulated via Cur-48-g-FA and Qcurd can provide a novel delivery platform for encapsulation of hydrophobic nutrients, including curcumin, in functional foods.