Evaluation of the Effects of Covering With Polyglycolic Acid Sheet on Wound Healing: A Pilot Histopathological Study

Purpose: Although the usefulness of polyglycolic acid (PGA) sheet for wound dressing has been recently reported, its histopathological effect on wound healing is not completely elucidated. This pilot study focused on the neo-epithelium formation and the remaining inflammation. Methods: Full-thickness defects of 8 mm were created on the back of seven-week-old rats. Four rats were divided into the control (raw surface) group and the PGA group, in which the wounds were covered with a PGA sheet. The wounds were assessed on days seven and 12 after wound creation. The length of neo-epithelium on day seven was measured by referring to Masson's trichrome (MT) and alpha-smooth muscle actin (alpha-SMA) staining. The remaining inflammation on days seven and 12 was assessed with ionized calcium -binding adapter molecule 1 (Iba-1) staining. Results: The average values of neo-epithelium length on day seven measured by referring to the borderline between MT staining and alpha-SMA expression were 959.2 mu m in the control group and 582.2 mu m in the PGA group. The number of Iba-1-positive cells on day 12 was significantly higher in the PGA group than in the control group. Conclusions: To assess the neo-epithelium length and the remaining inflammation, the alpha-SMA, MT, and Iba-1 staining may be appropriate.