Structural characterizations and potential delivery platform of glucan dendrimer-derived hydrogel

In response to the challenge of lysozyme (LZM) inactivation in the acidic environment of gastric juice, a pH-responsive gel delivery system based on glucan dendrimer (PG) was developed to achieve targeted intestinal delivery and enhance its bioavailability. Initially, PG was carboxymethylated. Then, a three-dimensional glycosidic bond entanglement network was constructed through enzymatic assembly to prepare the CMPG gel carrier. The structural characteristics of this carrier were characterized using various techniques, such as SEM, FTIR, XRD, and rheological analysis. Additionally, enzymatic hydrolysis experiments were carried out to elucidate the digestion characteristics of PG (or CMPG)-Gel. Subsequently, an in vitro simulated digestion model was employed to evaluate both the release behavior and activity retention rate of LZM under conditions mimicking gastric juice (pH 1.2) and intestinal fluid (pH 7.4). Within two hours in an intestinal environment, the release rate was reached up to 87.51 %, while the structural integrity of LZM was ensured to remain intact. This study represented a novel approach in which PG was utilized as a gel carrier through dual modifications involving carboxymethylation and enzymatic assembly for the first time. Targeted drug release was successfully achieved by leveraging pH responsiveness.