Carboxymethylpachymaran-Coated Zein Nanoparticles for Oral Delivery of Curcumin: Formation, Characterization, Physicochemical Stability, and Controlled Release Properties

The instability and poor solubility of curcumin limit its intake in the human body. In this work, curcuminencapsulated carboxymethylpachymaran/zein composite nanoparticles (ZMCNPs) were prepared by anti-solvent precipitation, and the morphology of composite nanoparticles was confirmed by transmission electron microscopy, and the interaction between carboxymethylpachymaran, zein, and curcumin was explored by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The encapsulation efficiency of curcumin by ZMCNPs (83.2%) was significantly higher than that of zein-curcumin nanoparticles (ZCNPs) (44.9%). The ZMCNPs also exhibit high ionic strength tolerance and light, heat, and storage stability. The in vitro release showed that ZMCNPs could effectively prevent the premature release of curcumin in the stomach (9.5%), while curcumin was better sustained in the small intestine stage (47.9%). Finally, the result of cytotoxicity assay in IEC-6 cells and HT-29 cells indicated the good biocompatibility of the ZMCNPs. Therefore, our study may provide some novel options for delivering biologically active substances.