The Effect of Human Placenta Extract in a Wound Healing Model

Human placenta had been used on wound healing such as burns, chronic ulcers, and skin defects. Recently, human placenta has been widely used in the form of human placental extracts (HPE) by clinical field. However, it is unclear what the effect of HPE is on wound healing. We studied the effect and mechanism of HPE on wound healing.In this study, 10 mice (imprinting control region mice, 5 week old males, 30 g) were divided into an experimental group and a control group. An 8-mm diameter single full-thickness skin defect was made on the back by skin punch biopsy. At least 2.0 × 10−3 mL/30 g HPE was injected into the boundaries of the wound. Wound size measurements were taken by digital image every 3 days over 2 weeks. Hematoxylin and eosin (H and E), transforming growth factor beta (TGF-&bgr;), vascular endothelial growth factor (VEGF), and CD31+ immunohistochemical stains were performed on the 6th and 14th day.The experimental group showed acceleration in the decrease of wound size compared with the control group from the third day to the ninth day. TGF-&bgr; on the 6th day showed a statistically significant increase in the experimental group. VEGF on the 14th day showed a statistically significant increase in the experimental group. CD31+ was increased in the experimental group as wound healing progressed, but this increase was not statistically significant. The total number of vessels increased in the experimental group, but this was not statistically significant.We conclude that administering HPE directly to a wound margin promoted wound healing. This mechanism appears to be related to an increase in TGF-&bgr; in the early phase of wound healing and VEGF in the late phase.