Preparation of self-healing oxidized sodium alginate-carboxymethyl chitosan hydrogel for sustained drug release

The self-healing oxidized sodium alginate-carboxymethyl chitosan hydrogel (OSA-CMCS) was synthesized based on dynamic imine bonds. Oxidized sodium alginate (OSA) was synthesized by oxidizing the uronic acid of sodium alginate, and self-healing OSA-CMCS hydrogels with different crosslinking degrees were prepared by Schiff base reaction with carboxymethyl chitosan, analyzed the microscopic morphology, viscoelastic properties, swelling properties, self-healing properties, enzymatic degradation properties and in vitro drug release properties of OSA-CMCS hydrogels. The results show that as the ratio of oxidized sodium alginate to carboxymethyl chitosan increase, the degree of crosslinking of the hydrogel gradually increase and the swelling ratio gradually decrease. OSA-CMCS hydrogel have the structural characteristics of highly porous and interconnected pores, and the pore size is in the range of 20~100 μm. At room temperature, OSA-CMCS hydrogel can realize self-healing within 6 hours without external stimulation. OSA-CMCS hydrogel is degradable, and as the degree of crosslinking increase, the degradation rate slow down. OSA-CMCS hydrogel have a slow-release effect on the water-soluble drug gemcitabine, and the drug release time can reach 4 days.