Formation and Characterization of Caseinate-Chitosan Nanocomplexes for Encapsulation of Curcumin

Curcumin holds promise as a therapeutic agent due to its capability of conferring several pharmacological activities. While curcumin shows efficacy in preclinical studies as an anti-cancer agent, its translation into the clinic as a drug has yet to be realized. One possible reason is its poor solubility and stability in water, which decreases the bioavailability. Here, we report the formation of biocompatible nanocomplexes (NCs) from caseinate (CS) and chitosan (CH) using an electrostatic interaction-based approach to stabilize and enhance water solubility of curcumin. The formation of CS-CH NCs (CCNCs) was studied as a function of CH concentration. We show that positively charged NCs, having size between approx. 250 nm with a narrow distribution was formed by adjusting CH concentration. CCNCs successfully entrapped curcumin with a high entrapment efficiency. Curcumin was possibly located in a hydrophobic region of CS as indicated by a blue-shift in the emission maxima of curcumin. Ultimately, the stability and water solubility of curcumin in CCNCs could be remarkably enhanced. These results suggest that CCNCs would be useful for increasing the potential of curcumin as a preventive or therapeutic agent.