Abstract:In the targeted delivery of probiotics， a key research focus in this field is how to prevent their destruction by gastric acid， bile， and other factors. Hydrogels are renowned for their three-dimensional network structure， demonstrating the ability to deliver active ingredients and encapsulate probiotics. In this study， a physically cross-linked hydrogel was prepared by leveraging the hydrogen bonding interactions between chitosan （CS） and sodium hyaluronate （SH）， and was utilized to encapsulate Lactobacillus rhamnosus. The hardness and swelling degree of the hydrogels were used as indicators to optimize the hydrogel preparation process by single-factor and response surface tests. The results showed that the SH concentration and acetic acid（HAc） concentration were significant factors affecting the hardness and swelling degree of the hydrogels， and the CS concentration had a significant effect on the swelling degree of the hydrogels. The optimized conditions for constructing the hydrogels were as follows： a CS concentration of 1.60 g/100 mL， an HAc concentration of 0.75%， and an SH concentration of 1.60 g/100 mL. Under these conditions， the hydrogel exhibited a hardness of 1 160.28 g and a swelling degree of 1 261.79% and had a three-dimensional network structure with relatively thin walls and a high swelling degree. In addition， it also demonstrated good probiotics loading properties， with a loading capacity and loading rate of 8.76 lg（CFU/mL）and 76.91% respectively.