Construction of self-assembled polysaccharide nanoparticles from Lanzhou lily for curcumin delivery: Insights into physicochemical properties and in vitro immunomodulation

The aim of this study was to construct a series of BA-esterified Lanzhou lily polysaccharides (BLLP) capable of self-assembling into nanoparticles (BLLP NPs). And BLLP NPs achieved synergistic immune-enhancing effects with curcumin (Cur). The successful synthesis of BLLP was confirmed by FT-IR and 1 H NMR. The BLLP NPs exhibit a regular spherical morphology, with a particle size range of 260–410 nm and good dispersion (PDI < 0.32) as determined by DLS. These nanoparticles showed good biosafety (cytotoxicity >100 %, hemolysis <5 %) and can be effectively taken up by cells. The loading capacity of BLLP NPs for Cur can reach 17.60 %, and the encapsulation rate was 48.69 %. After encapsulation, the water solubility, photostability and thermal stability of Cur in BLLP-Cur NPs were enhanced by 83.1-fold, 2.6-fold and 1.4-fold, respectively, compared with free Cur. In vitro simulated release and in vivo absorption showed that BLLP-Cur NPs had a better release from the intestines (in accordance with the Korsmeyer-Peppas model) and a longer intestinal residence time. In in vitro immunoreactivity assays (neutrophil phagocytosis, NO release, cytokine and transcription factor levels) BLLP-Cur NPs exhibited the best immunoreactivity due to the synergistic effect of Cur and BLLP NPs. This study could support the construction of curcumin synergistic bioactive nano-delivery system and diversified applications of Lanzhou lily polysaccharides in functional foods.