Development of a novel triple-component polysaccharide-based nanocarrier: Synthesis and characterization of a Dextran/Zein/ZIF-8 nanoemulsion for pH-sensitive, controlled release and enhanced anticancer activity of curcumin.

The therapeutic properties of curcumin, especially in cancer treatment, are well known, although its rapid metabolic degradation and poor solubility limit its clinical use. This research uses a double emulsion technique to develop a novel Dextran/Zein/ZIF-8@Curcumin nanoemulsion. Chemical and crystalline characterizations were performed with FTIR and XRD, respectively. The loading and entrapment of cargo significantly increased with adding ZIF-8 into the nanocarrier, reaching LE (%) and EE (%) values of 46.25% and 83%, respectively. Morphological studies (FE-SEM and DLS) show an efficient size range, uniform distribution, and dense spherical morphology. The surface charge measurement reveals a high negative value of -39 mV, indicating good colloidal stability. The pH stimulus-responsive release of the loaded CUR from nanoemulsion was observed through different release profiles under acidic (pH 5.4) and neutral (pH 7.4) conditions. A high release rate was identified at the acidic pH, whereas a slower controlled release occurred at the normal pH. Fitting the experimental release data into kinetic models confirmed pH sensitivity, with the Korsmeyer-Peppas model providing the best fit in both environments. These improvements show their effect in the MTT assay, increasing cellular inhibition in Hep-G2 cells and reducing cell viability to nearly 50%. Meanwhile, the controlled low release rate under normal conditions enhances the viability of normal cells and makes the nanocarrier more biocompatible.