Platelet-rich plasma stimulates angiogenesis in mice which may promote hair growth

BACKGROUND Platelet-rich plasma (PRP) is an autologous concentration of human platelets in plasma. In this paper, we aimed to investigate the effect of PRP on hair growth. METHODS Platelet-rich plasma and platelet-poor plasma were prepared by sterile centrifugation and injected into shaved dorsal skin of mice (n = 10). Saline injection was used in the control group. The length of randomly plucked hairs was measured at 8, 13, 18 days after PRP injection. Histological examination was preformed to observe the histologic changes of skins. The immunohistochemistry analysis of CD31 was performed to detect the changes of hair length and formation of new vessels. RESULTS At 13 and 18 days after the last injection, the hair length of mice in PRP group (4.24 ± 0.60 and 8.29 ± 0.48 mm, respectively) was significantly longer compared with the control group (3.70 ± 0.52 and 7.21 ± 0.64 mm, p < 0.05). No significant difference in the hair length was found between the PPP group and the control (p > 0.05). In addition, the number of CD31-positive vessel in the PRP group (9.90 ± 0.60) was more than that in the control group (8.60 ± 2.34, p < 0.05). CONCLUSION Platelet-rich plasma might promote hair length growth and increase the number of hair follicles by inducing angiogenesis.