Formation, Physicochemical Stability, and Redispersibility of Curcumin-Loaded Rhamnolipid Nanoparticles Using the pH-Driven Method

The aim of the present work was to fabricate the curcumin-loaded rhamnolipid nanoparticles using the pH-driven method to enhance the physicochemical stability and redispersibility of curcumin. The mixture of curcumin and rhamnolipid could be spontaneously assembled into the curcumin-loaded rhamnolipid nanoparticles with a small size (107 nm) and negative charge (-45.5 mV). Curcumin molecules could bind to rhamnolipid molecules through hydrophobic effects and hydrogen bonds. The effect of different mass ratios of rhamnolipid and curcumin (1:2, 1:1, 2:1, 4:1, 6:1, and 8:1) on the functional property of the curcumin-loaded rhamnolipid nanoparticles was investigated. With the rise of rhamnolipid and curcumin mass ratio, the encapsulation efficiency of curcumin in the nanoparticles was increased from 44.59% to 81.12% and the loading capacity of curcumin was elevated from 10.14% to 31.67%. When the mass ratio of rhamnolipid and curcumin was 4:1, the curcumin-loaded rhamnolipid nanoparticles exhibited better physical stability, pH stability, and redispersibility. Moreover, the nanoparticles could effectively protect curcumin against the photodegradation and thermal degradation. Therefore, the rhamnolipid nanoparticles have the potential to be applied as a nanodelivery system for bioactive molecules in functional foods.