Abstract: BACKGROUND: It has been confirmed that the mixing of decellularized matrix and polymer electrospinning can not only improve the structural properties of fibers, but also preserve the biological decellularized of decellularized matrix. However, there is no relevant report on the preparation of skin tissue engineering scaffolds by electrospinning polyurethane and decellularized skin matrix.
OBJECTIVE: To investigate the reparative effect of a decellularized skin matrix/polyurethane blended fibrous scaffold on rat skin defects. 
METHODS: Polyurethane electrospun fibrous scaffold and decellularized skin matrix/polyurethane blended fibrous scaffold were fabricated using the electrospinning technique. The fiber structure was observed under scanning electron microscope. Rat adipose mesenchymal stem cells were inoculated on two kinds of scaffolds respectively. The morphology of the scaffolds was observed under scanning electron microscope. Three full-thickness skin defects of 1 cm×1 cm were fabricated on the back of 10 SD rats. Polyurethane electrospun fibrous scaffolds (control group) and decellularized skin matrix/polyurethane blended fibrous scaffolds (experimental group) were implanted in two of the defects, and no material was implanted in the remaining defects (blank control group). The skin wound healing was observed at 1, 2, and 3 weeks after operation. At 3 weeks after implantation, the wound was stained with hematoxylin and eosin and the scar area was calculated.
RESULTS AND CONCLUSION: (1) Under scanning electron microscope, the two kinds of electrospun fibers were reticulated, and the rat adipose mesenchymal stem cells attached to the fibers on the two kinds of scaffolds, and the adhesion was good. (2) With the extension of the postoperative time, the skin wounds of each group gradually healed. By week 3 after the operation, the skin wounds of the experimental group and the control group were basically healed, and small ulcers could be seen on the wounds of the blank control group. Hematoxylin-eosin staining of skin wounds showed that the epidermal coverage of the wound was basically complete in the control group and the experimental group, and fibroblast growth and inflammatory cell infiltration could be seen in the dermis. In addition, the collagen fibers of the wound in the experimental group were abundant and arranged in a regular order, basically parallel to the epidermal surface. The wound epidermis of blank control group was still defective. The scar area of the experimental group was smaller than that of the other two groups (P < 0.05, P < 0.01). (3) These results indicate that the decellularized skin matrix/polyurethane blended fibrous scaffold can effectively repair full-thickness skin defects and improve scar formation in rats. 

Key words: decellularized skin matrix, polyurethane, electrospinning, skin defect, scar