Injectable, self-healable and adhesive hydrogels using oxidized Succinoglycan/chitosan for pH-responsive drug delivery

We prepared chitosan (CS) based multifunctional hydrogels using oxidized succinoglycan (OSG) with a semi-dissolving acidified sol-gel transition method. OSG cross-linked CS hydrogels (OSG/CS) was prepared by aldehyde-amine Schiff-base reaction. OSG/CS increased not only thermal stability but also improved mechanical strength by 5.75 times. Through the tensile and strain sweep test, OSG/CS showed excellent self-healing properties by 98.82% and 99.89%, respectively. It showed the high compressive stress of 173 kPa at 60% strain, the adhesive strength of 2763 kPa, and the antibacterial effect of 90%. Furthermore, OSG/CS showed a pH-controlled drug release pattern, where a change of pH from 7.4 to 2.0 accelerated for 5-fluorouracil release from 60% to 90%. WST-8 assay demonstrated that OSG/CS maintained 97.30% cell viability and 98.84% cell proliferation after 7 days, indicating the potential as biocompatible hydrogel materials such as wound healing, tissue engineering and drug release systems.