Green co-assembled nanoparticles from ovomucin and polysaccharides: Interfacial interaction-driven superior encapsulation and delivery of hydrophobic bioactives.

The interaction-driven assembly of ovomucin (OVM) with differently charged polysaccharides was investigated in this study, aiming to construct stable nanocarriers for hydrophobic nutrient delivery. Systematic phase behavior analysis and revealed that sodium alginate (SA) and chitosan oligosaccharides (COS) synergistically stabilized OVM over a wide pH range through hydrogen bonds and electrostatic interactions. OVM-SA-COS (OSC) nanoparticles were synthesized via electrostatic layer-by-layer self-assembly, exhibiting uniform size, high solubility, and excellent stability under varying pH and ionic strength conditions. Subsequently, using lutein (LUT) as a representative to evaluate the delivery of hydrophobic substances, the encapsulation efficiency of OSC nanoparticles for LUT was 88.86%. Release kinetics studies indicated that the release of LUT from OSC nanoparticles in simulated gastric fluid followed the Higuchi model (R2 > 0.99), indicating a diffusion-controlled mechanism. In simulated intestinal fluid, the release profile conformed to the Korsmeyer-Peppas model and release exponent n was 0.4, indicating that diffusion synergized with carrier dissolution to achieve pH-responsive sustained-release and rapid intestinal release. After 56 days of storage under various temperature and pH conditions, the retention rate of encapsulated LUT was obviously higher than that of free LUT. DPPH scavenging assays indicated that the antioxidant activity of OSCL nanoparticles was about 2-3 times that of free LUT. The nanoparticles showed excellent biocompatibility in cellular assays. This work provides a novel and rational design for protein-polysaccharide composite nanocarriers, offering a promising strategy for the delivery and potential improvement of the oral bioavailability of hydrophobic bioactive compounds in functional foods and nutraceuticals.