Chitosan/squid ring teeth protein hydrogels for the controlled release of curcumin

Biocompatible and degradable hydrogels are extensively utilized for the delivery and controlled release of bioactive agents. Chitosan/squid ring teeth protein (SRT) hydrogels (CH/SRTs) cross-linked by genipin were fabricated, and their gel properties and structural characteristics were analyzed across varying SRT contents. Additionally, the curcumin-release behavior of curcumin-loaded CH/SRTs (Cur-CH/SRTs) was evaluated. Results indicated that increasing SRT content enhanced the elasticity, viscosity, gel strength, hardness, and thermal stability of CH/SRTs. Specifically, the hardness and gel strength of CH/SRT3 (Chitosan: SRT, 1:1) were 207.8 % and 220.9 % higher, respectively, than those of the pure chitosan hydrogel. Higher SRT content significantly increased the curcumin encapsulation efficiency of Cur-CH/SRTs while substantially reducing curcumin release in simulated gastrointestinal fluid. Compared to the curcumin-loaded pure chitosan hydrogel, the curcumin release rate of Cur-CH/SRT3 decreased by 56.12 % after 480 min of simulated gastrointestinal digestion. These findings were attributed to reduced swelling and improved gel strength of Cur-CH/SRTs with SRT addition. Consequently, CH/SRTs demonstrate potential for applications in the controlled release of drugs and bioactive agents.