Pharmacodynamic study: Astragaloside IV/chitosan/polylactic acid composite electrospinning scaffold for wound healing in diabetic rats

The wound dressing plays an important role in wound repair as a medical textile that temporarily replaces the skin. However, ordinary wound dressings can only cover wounds and supply a protecting function for wounds, cannot meet some special requirements of chronic wounds, especially diabetic wounds. To overcome these drawbacks, in this study, a novel AS/CS/PLA nanofiber functional dressing was developed to promote diabetic wound healing by electrostatic spinning technology. The pharmacodynamics of AS/CS/PLA nanofiber functional dressings were evaluated. In in vitro pharmacodynamic experiment, the effect of the dressing on cell proliferation was detected by MTT assay. Cell adhesion to the dressing was observed by scanning electron microscopy (SEM), and the cell migration ability promoted by the dressing was evaluated by an in vitro cell scratch test. In in vivo pharmacodynamic experiment, we established a skin wound model in diabetic rats. On the 7th and 15th days, we collected tissue samples from both the surrounding area and the wound area. The expressions of CD31 and TGF-β in wound tissue were detected by H&E and Masson three-color staining, respectively. The results showed that the AS/CS/PLA nanofiber functional dressing could promote cell proliferation, adhesion, and migration. It also increased collagen deposition and granulation tissue formation at wound. Moreover, it promoted the expression of CD31 and TGF-β factors at early stage, thereby accelerating wound healing. Our results indicated that the AS/CS/PLA nanofiber functional dressing have a potential as a treatment material to accelerate diabetic wound healing.