Abstract: Abstract: Objective To study the effects of different treatment methods of platelet-rich plasma (PRP) on skin wound healing in mice. Methods A total of 27 C57BL/6J male mice were used in this study, 12 of them were used to prepare PRP, and the other 15 mice were randomly divided into control group, PRP injection group and PRP gel group. There were 5 mice in each group. Models of skin injury were established in all three groups of mice. For the PRP injection group, the skin wound was equally divided into 6 points and subcutaneously injected PRP with 0.1 mL at each point. The control group was injected the same amount of saline with the same method. For the PRP gel group, PRP was activated to prepare gel to cover the skin wounds of mice. All three groups were given medicine only once on the day after surgery. The wound areas were photoed and calculated on the 0, 3, 7, 11, and 14 day respectively. On the 14th day, mice of the three groups were sacrificed and the skin tissues around the wound were collected. The collagen expression was evaluated by immunofluorescence staining. The mRNA expressions of collagen type Ⅰ alpha 1 chain (COL1A1), collagen type Ⅲ alpha 1 chain (COL3A1), transforming growth factor-beta 1 (TGF-β1), platelet derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) in the wound site were detected by qRT-PCR. Results Compared with the control group and the PRP injection group, the skin wounds healed significantly and the wound area decreased in the PRP gel group at different time points after surgery (P＜0.05). At 11 and 14 days after surgery, the wound area decreased in the PRP injection group compared with that of the control group (P＜0.05). At 14 days after operation, collagen expressions were significantly increased in the PRP gel group compared with those of control group and the PRP injection group, and mRNA levels of VEGF, COL1A1, COL3A1, TGF-β1 and PDGF increased (P＜0.05). Conclusion The preparation of gel from the PRP activation can effectively repair the skin defects of mice.

Key words: wound healing, skin, platelet-rich plasma, gels, collagen