Hydrogel Based on Bletilla Striata Polysaccharide for Sustained Sodium Danshensu Release for Wound Healing

Bletilla striata polysaccharide (BSP) is effective at healing wounds and has important application value in the research and development of biomedical materials. In this study, BSP, chitosan, and sodium β-glycerophosphate were used to generate a complex hydrogel with a very small pore size of 10-30 μm without the use of cross-linking agents. By improving the cross-linking density, the mechanical property defects caused by excessive BSP dissolution were overcome without affecting its physiological activity. Moreover, the small molecule Danshen sodium (SDSS) was loaded into the three-dimensional network of this hydrogel to form a hydrogel drug carrier system. SDSS could be released in the long term, and the total amount released after 53 h was 96.26 ± 2.57%. The BSP hydrogel had good water absorption (169.47 ± 4.54%) and bonding properties. In vitro studies confirmed that it has a good antibacterial performance and biocompatibility and the ability to promote cell proliferation (>200%) and migration. Molecular experiments confirmed that the hydrogel promotes collagen expression. In vivo experiments using a mouse wound healing model confirmed that the hydrogel has an excellent ability to promote wound healing, particularly during the first 7 days of the wound. The wound healing rate of the hydrogel group was higher than that of the blank group by 27.61% (p < 0.05), and the effect of the hydrogel to promote wound healing was confirmed by wound tissue staining.