Multiple non-covalent interactions used to construct epigallocatechin gallate-sophorolipid-wheat gliadin nanoparticles: Enhanced stability and delivery performance in digestion

In this study, epigallocatechin gallate (EGCG) and sophorolipid (SPL) were employed to enhance the water-solubility and stability of wheat gliadin nanoparticles, as well as the delivery properties. The incorporation of EGCG and SPL increased the nanoparticle size to some extent but also introduced additional negative charges. Investigation of non-covalent interactions revealed that hydrogen bonding, hydrophobic interactions, and electrostatic interactions were key contributors to the behavior of the nanostructures. The OH, C H and N H groups in wheat gliadin were involved in the reaction earlier than the C O groups. These interactions modified the structure of wheat gliadin. Molecular docking studies indicated that EGCG and SPL bind to distinct sites, with van der Waals forces, π–Sigma interactions, and other forces complementing the primary binding interactions. Loading experiments demonstrated that resveratrol-loaded EGCG-SPL-wheat gliadin nanoparticles exhibited the highest loading efficiency, superior stability, and a clear trend of controlled release in vitro digestion tests.