Construction of a charge-reversal polyelectrolyte nanocarrier for targeted intestinal releasing of kidney tea saponin based on sodium alginate/ε-polylysine/alliin.

Herein, a pH-responsive delivery system based on sodium alginate (ALG), ε-polylysine (PLL) and alliin (ALL) has been designed. The innovative use of the charged nature of alliin to prepare carriers loaded with kidney tea saponins has rarely been reported in the literature before. The size and morphology of the complex was quantified by dynamic light scattering (DLS) analysis and scanning electron microscopy (SEM), exhibiting a size of 141 ± 1 nm. The carrier shows effective pH-responsiveness, stability in the gastric environment and dissociation in the intestinal environment. Kidney tea saponins can easily pass through the stomach directly into the intestine after encapsulation at pH = 1. Furthermore, in vitro simulated digestion was used to validate the efficacy of the delivery system. When kidney tea saponin was administered orally, it could reach the intestinal tract barely. However, when it was encapsulated in the carrier, approximately 60 % of the kidney tea saponin could be delivered to the intestinal tract. The strategy increases bioavailability of kidney tea saponins within the intestine successfully. The findings indicate that ALG-PLL-ALL may serve as a suitable delivery system for the intestinal targeted releasing of health factors that are susceptible to hydrolysis and unstable in the stomach.