Application Of Bletilla Striata Polysaccharide Hydrogel In Promoting Healing Of Diabetic Wounds

Objective : By applying bletilla striata polysaccharide hydrogel to diabetic mice wounds,observe the healing effect,which provided scientific basis and new ideas for clinical dressing development.Method : Bletilla striata polysaccharide(BSP),carbomer 940(CBM 940),and carboxymethyl chitosan(CMC)are used as raw materials for the hydrogel to be cross-linked into Bletilla striata polysaccharide hydrogel(CCHG/BSP).First,the hydrogel is characterized by scanning electron microscope,rheometer,and water retention experiment,and the safety of the hydrogel is tested through hemolysis experiment.Subsequently,mouse L929 fibroblasts were used as the cell model for in vitro experiments,and the MTT method was used to detect the effect of the hydrogel on cell proliferation;the scratch test method was used to detect the effect of the hydrogel on cell migration.Prepare 48 SPF male ICR mice(6-8 weeks,weight 18-24g)and randomly divide them into 4 groups,each with 12 mice.After 1 week of adaptive feeding,150mg/kg dose,intraperitoneal injection of 1% Streptozotocin(STZ)solution induces diabetes.A round wound with a diameter of 8mm was made on both sides of the back of the successfully modeled mouse.Two wounds were made for each mouse.After a silicone ring was externally sewn,physiological saline(NS),simple hydrogel(CCHG),and Bletilla striata were given.Polysaccharide aqueous solution(BSP),Bletilla striata polysaccharide hydrogel(CCHG/BSP)treatment,observe the healing situation every day,take pictures and record.The tissues around the wound were taken on the 3rd,7th,14 th,and 21 st days for histological analysis and cytokine detection to observe the changes of skin cell pathology and related factors.Take the main internal organs of the mice 21 days after treatment in each group,and observe the structure and inflammatory cell changes with HE staining,and test the safety of the materials again.Result : After successfully preparing the Bletilla striata polysaccharide hydrogel,its characterization showed that the hydrogel has a loose and porous structure,good mechanical properties and good water retention.Hemolysis experiments show that the hydrogel has good safety.Cell experiments show that the hydrogel can effectively promote the proliferation and migration of mouse L929 fibroblasts.In in vivo experiments,the back wounds of each group of mice tended to heal over time.Among them,the NS treatment group has the slowest healing speed,and the CCHG/BSP group has the fastest healing speed,which is better than the CCHG and BSP treatment groups.HE staining showed that the number of inflammatory cells in the CCHG/BSP group decreased faster,the healing quality was better,and skin appendages appeared.Masson staining showed that the collagen production in the CCHG/BSP treatment group was significantly better than the other three groups,the collagen arrangement was more orderly,and there was no excessive deposition of collagen.In the study of CD31 immunohistochemistry,the expression of CD31 in the CCHG/BSP treatment group was higher than the other three groups,with significant statistical differences.In the detection of Ki67,the peak of cell proliferation appeared in the early stage of CCHG/BSP treatment group,earlier than that of NS treatment group.The enzyme-linked immunosorbent test showed that the expression of TNF-α and IL-6 in the CCHG/BSP treatment group increased earlier and faster,and then gradually decreased,without the peak of inflammation,which was obviously different from the NS group.In the CCHG/BSP group,TGF-β1 expressed higher in the early stage,then gradually continued to increase,and then slightly decreased in the late healing period,which was more conducive to wound healing and improved healing quality.HE staining of internal organs showed that each group of materials had good safety.Conclusion : Bletilla striata polysaccharide hydrogel has the characteristic three-dimensional structure of hydrogel,and its mechanical properties and safety are good.In vitro experiments have verified its ability to promote cell proliferation and migration,and further in vivo experiments have shown that it can regulate inflammation,promote cell proliferation,migration,and angiogenesis,thereby promoting wound granulation tissue regeneration and collagen deposition,and ultimately promoting the wound healing of diabetic mice.