Enhancing stability of curcumin-loaded casein nanoparticles by adding liposomal nanoparticles

Curcumin (Cur) is a natural polyphenol found in turmeric. Its application as a functional ingredient in foods, supplements, and pharmaceuticals is dramatically limited due to its poor stability, water solubility, and bioavailability. The purpose of this research was to enhance the performance of curcumin using advanced encapsulation technologies. Curcumin-loaded casein nanoparticles (CCNP) were prepared using the pH-driven method, and then different concentrations of liposomes (LP) were added to assess their impact on the stability of this delivery system. Then, CCNP, curcumin liposome nanoparticles (CLP), and the optimal ratio of CCNP/LP complexes were selected for thermal and storage stability studies. Their formation mechanism was studied by atomic force microscopy (AFM), isothermal titration calorimetry (ITC), and Fourier transform infrared (FTIR) methods. Furthermore, the impact of pH and salt (NaCl) on their stability was also investigated. The results show that LP can adsorb onto the surfaces of CCNP through hydrogen bonding and electrostatic attractive interactions at certain concentrations, which reduces the surface hydrophobicity of the nanoparticles, thereby improving their resistance to environmental stresses. This study provides information that can be used to improve the bioavailability of curcumin.