Assembly of kafirin/carboxymethyl chitosan nanoparticles to enhance the cellular uptake of curcumin

Abstract Kafirin, the prolamin protein from sorghum, has been utilized to form two types of nanocapsules to enhance the cellular uptake of curcumin: (1) kafirin based colloidal particles containing curcumin (cc-kaf) prepared by solvent induced kafirin self-assembly; and (2) kafirin/carboxymethyl-chitosan nanoparticles (cc-kaf/CMC) prepared by acid-induced aggregation. Both nanocapsules showed spherical morphology with cc-kaf/CMC presenting larger average particle sizes as determined by dynamic light scattering (DLS) and atomic force microscopy (AFM). The encapsulation efficiency and loading efficiency were 55.0 ± 1.1% and 5.0 ± 0.1% for cc-kaf and increased to 86.1 ± 2.1% and 6.1 ± 0.2% after introducing CM-chitosan. Hydrogen bonding, electrostatic attraction and hydrophobic interaction were found to be the major driving forces for particle formulation and curcumin encapsulation. The involvement of CM-chitosan improved the photo stability, dissolution profile in simulated gastrointestinal tract and cellular uptake of curcumin. A schematic illustration of the formation of cc-kaf and cc-kaf/CMC and their corresponding performance were proposed. The designed methodology suits particularly for the encapsulation of water-insoluble nutraceuticals with the enhanced encapsulation efficiency and nutraceutical uptake.