Encapsulation and controlled delivery of curcumin by self-assembled cyclodextrin succinate/chitosan nanoparticles

Low aqueous dispersibility and poor stability severely restrict the bioaccessibility of curcumin in health-related products. Constructing highly effective delivery carriers is essential to overcome the limitation. In this study, a novel and simple self-assembly process driven by electrostatic interaction was developed to prepare cyclodextrin succinate/chitosan (SACD/CS) nanoparticles. Spherical SACD/CS nanoparticles were obtained by adjusting the ratio of SACD:CS to obtain an average size and ζ-potential of around 500 nm and 20 mV, respectively. By analyzing the intermolecular interactions and crystalline structure of SACD/CS nanoparticles, it is indicated that SACD could act as crosslinking nodes, and contributed to transformation of molecular arrangement in the nanoparticles. The noncytotoxic SACD/CS nanoparticles were further used as curcumin carriers and showed significant improvement on curcumin stability, with the retention index of curcumin under physiological conditions increased from 19% to 62%. Moreover, the Cur-SACD/CS nanoparticles displayed controlled release behavior of curcumin during in vitro digestion, with 9%, 22%, and 44% of curcumin released at the end of the oral, stomach, and small intestine stage, respectively. This study developed a novel and effective strategy for oral delivery of curcumin, showing promising potential for improving the bioaccessibility and bioavailability of bioactive compounds like curcumin.