Developing functional capsules for drug delivery in the digestive system and alcohol-induced gastric ulcer prevention using interfacial whey protein amyloid fibril/gum arabic complex coacervation.

The remarkable properties of amyloid fibrils (AFs), including robust mechanical stiffness, high specific surface area, excellent biocompatibility, and superior thermochemical stability, make them promising candidates as drug carriers and therapeutic materials in biomedical applications. In the present study, we aimed to synthesize three-dimensional AF-polysaccharide hybrid capsules via interfacial coacervation and to evaluate their feasibility as drug delivery vehicles for gastric ulcer (GU) prevention. Capsules composed of AFs as the polycation and gum arabic (GA) as the polyanion were prepared, and the optimal pH conditions and strength of electrostatic interaction (SEI) were determined for capsule preparation. Furthermore, the surface microstructure, thermal properties, free radical scavenging activity, and reducing power of the AF/GA hybrid capsules were examined. In addition to determining the encapsulation efficiency (EE%), loading capacity (LC%), and mucin binding efficiency (MBE) of hybrid capsules, the drug-matrix interactions between riboflavin (RF) and the hybrid capsules were investigated using infrared spectroscopy. The kinetics and mechanism of the in vitro release of RF from the hybrid capsules in the simulated salivary and gastric conditions were examined using the first-order model, the Korsmeyer-Peppas model, and theoretical kinetic models derived from Fick's second law of diffusion. Finally, the in vivo gastroprotective effect of RF-loaded capsules against alcohol-induced GU in C57BL/6 mice was assessed using various serological and histopathological analyses, which demonstrated the efficacy of these capsules in preventing alcoholic GU. This study provides a valuable example of using amyloid/polysaccharide-based coacervate capsules for drug delivery and GU prevention.