Preparation of zein-rutin supramolecular nanoparticles using pH-ultrasound-shifting: binding mechanism, functional properties, and in vitro release kinetics.

The limited solubility of rutin necessitates the development of efficient delivery systems. This study developed zein-rutin supramolecular nanoparticles (Z-R-P-U) using a pH-ultrasound-shifting method, achieving high encapsulation efficiency (87.89 ± 1.28 %) and loading capacity (23.97 ± 0.56 %). Multispectral analysis and molecular docking results indicated that hydrogen bonding, van der Waals forces, and hydrophobic interactions are the dominant supramolecular forces in the binding between zein and rutin. Z-R-P-U exhibited a uniform spherical structure with a particle size of approximately 150 nm, maintaining stability below 200 nm after 28 days of storage. Compared to free rutin, Z-R-P-U increased solubility by 9.2 times and significantly enhanced antioxidant activities, including DPPH scavenging capacity (10.26 %), ABTS scavenging capacity (12.23 %), and ferric-reducing antioxidant power (31.43 %). Additionally, bioaccessibility improved notably, and in vitro release followed first-order kinetics governed by Fickian diffusion. This method efficiently encapsulates polyphenols, offering novel strategies for their application in food and pharmaceutical industries.