Development of controlled-release soy β-conglycinin nanoparticles containing curcumin using genipin as crosslinker

Recent advances in nanocarriers for bioactives have focused on finding more sustained-release, natural materials. In this study, genipin-crosslinked soy beta-conglycinin (beta-CG)-curcumin nanoparticles (G-SCP) significantly enhanced the stability of curcumin and released curcumin controllably in the gastric environment. The optimal intra-particle crosslinkage for G-SCP was obtained under the genipin concentration less than 0.2 mg/mL and stirring at 37 degrees C for 24 h, which was confirmed by ninhydrin assay, amino acid analysis, dynamic light scattering (DLS) and flourier transform infrared spectroscopy (FT-IR) analysis. Transmission electron microscopy (TEM), DLS and release of trichloroacetic acid (TCA)-soluble nitrogen were used to systematically evaluate the sustained-release behavior and mechanism of curcumin from the G-SCP. The anti-cancer activity of oral-intake curcumin was investigated by collecting the G-SCP digestion supernatant and analyzing its cellular uptake and proliferation in HepG2 cells. The results revealed that the bioaccessible curcumin released from G-SCP had stronger anti-proliferation for HepG2 cells than free curcumin. On normal liver cells L02, interestingly, bio-accessible curcumin had considerably lower cytotoxicity than it did on HepG2 cells. These findings suggested that the G-SCP was a protein-based carrier that could effectively transfer insoluble bioactives in the gastric environment.