Glycerol-compressed self-assembly nanogel based on ovomucin and chito-oligosaccharide: A novel green strategy for curcumin delivery

Abstract

Nano-gel technology has been one of the popular methods to solve the low bioavailability of hydrophobic active substances. In this work, Ovomucin (OVM) was combined with chito-oligosaccharide (COS) by self-assembly, followed by condensation of complexes initiated via glycerol solution to produce green nanogel delivering curcumin. The successful encapsulation of curcumin was confirmed by UV–Vis spectrum and fluorescence microscopy. In addition, the morphology of the nanogel was nearly spherical with a small average hydrodynamic diameter (115.43nm), uniform particle size distribution (PDI = 0.266), and intense surface negative charge (−23.56mV). The vitro-release simulation assay showed that the nano-gels have good sustained release ability. The antioxidant activities of free curcumin and curcumin-loaded nano-gels were investigated by ABTS, DPPH, and H 2 O 2. The results of FTIR and XRD confirmed that curcumin disperses uniformly in the whole system through hydrogen bond and hydrophobic interaction between the nanogel. Curcumin in nanogel enabled easier access to free radicals in water phase, thereby possessing stronger antioxidant activity than free curcumin. Furthermore, cytotoxicity test results showed that nanogel has no obvious toxicity signs on cell viability. Hence, this work holds a grand promise for safe and efficient oral curcumin delivery while possessing universal significance for the extension of using OVM as an efficient and functional encapsulating agent to broad applications in food and health industries. OVM was mixed with curcumin and bound to each other by hydrophobic interaction and hydrogen bond. COS induced the formation of early nanogel by electrostatic action. Glycerol compressed the gel to produce the final nanogel. • The nanogel was synthesized in a green way by glycerol compression and self-assembly. • The average hydrodynamic diameter of curcumin-loaded OVM nanogel was only 115.43 ± 1.60 nm and size distribution was narrow. • The fluorescence quenching of the nanogel confirmed the encapsulation of curcumin. • The Cur-OVM-COS nanogel showed a better sustained-release effect during simulated gastrointestinal digestion than the free curcumin. • The antioxidant activity of encapsulated curcumin was improved.