The Effect And Mechanism Research Of Hydroxysafflor Yellow A And Its Preparation On Diabetic Chronic Ulcer

Objective:To investigate the diabetic ulcer repair effect of interpenetrating network hydrogel with topical delivery of Hydroxysafflor Yellow A,which was selected by some experiments and to explore the related mechanisms of HSYA-based chitosan-gelatin hydrogel on diabetic wound healing.Furthermore,we combined HSYA with deferoxamine to improve the repair effect and investigated the relevant mechanisms.Method:1.HSYA was selected as the proper drug agents which can accelerate diabetic wound healing through some cell and animal experiments and the mechanism of wound healing was further studied in vitro.2.The hydrogel dressing containing HSYA was prepared and the analysis method was established.The morphology,porosity and drug release of the gel were also investigated.In vivo,the diabetic rat full thickness splinted excision model was established to evaluate the effect of HSYA-loaded gels.The content of VEGF and TGF-?1 in the repaired skin were measured by Elisa assay and Mason's trichrome staining respectively.3.The effect and relevant mechanisms of HSYA/DFO-loaded hydrogel on diabetic ulcer was investigated in vitro and in vivo.The crosslinker is genipin.In vitro,the effects of combined use of HSYA and DFO on the secretion of HIF-1?,cell migration and angiogenesis were investigated.In vivo,the effect of HSYA/DFO hydrogel dressing on the healing rate of diabetic ulcer was investigated.HE staining,CD31,HIF-la tissue immunofluorescence staining and photoacoustic blood flow observation were performed to evaluate the quality of repaired skin.Results:1.HSYA exhibited anti-inflammatory effects in a concentration-dependent manner.HSYA can also promote the migration of keratinocytes and the formation of neovascularization to accelerate the healing of skin ulcers.2.HPLC analysis method of HSYA was established and the hydrogel with chitosan-gelatin mass ratio of 5:5 was selected for experiment.The prepared gel showed a porous three-dimensional struct?re with sustained release property.With the chitosan-gelatin as a topical vehicle,HSYA hydrogels kept the initial period of fast release after 1h(about 40-50%)whereas followed by sustained release until 10h.It also showed good water absorption and breathability,which can be applied to skin easily.The results of experiments in vivo demonstrated that HSYA could significantly accelerate diabetic ulcer healing,the highest expression of VEGF and TGF-?1 was found in the skin tissue after HSYA gel's treatment,and some hair follicles and blood vessels were also found in HSYA-loaded hydrogel treated group.But compared with the normal skin,the quality of repaired skin was not pretty contented,so we considered the combination therapy.3.The combination of HSYA and DFO showed a certain degree of synergistic effect on the secretion of HIF-la,cell migration and angiogenesis.The best applied concentration is the 0.2mM HSYA with 0.0375mM DFO.The results of pharmacodynamic experiment in vivo and tissue staining showed that both HSYA/DFO loaded gel and HSYA/DFO solution could accelerate the wound epithelization and promote ulcer healing by improving angiogenesis and up-regulating the content of HIF-1?.The best quality of skin repair was achieved after the treatment of HSYA/DFO-loaded gel,which showed the highest thickness of epidermis and granulation tissue.And the dermis of the repaired skin had more abundant blood flow,which was the closest to the normal skin.Conclusion:The prepared hydrogel dressing can be used as an excellent topical delivery system for the repair of diabetic ulcer.When HSYA and DFO are applied in combination,the synergistic effect on the healing of ulcer can be realized.