Promotional effect of platelet-rich plasma on hair follicle reconstitution in vivo.

[BACKGROUND] Platelet-rich plasma (PRP) containing various growth factors has attracted attention in various medical fields. PRP has recently been used during hair transplantation to increase hair density.

[OBJECTIVE] To investigate the effects of PRP on hair follicle (HF) reconstitution.

[METHODS AND MATERIALS] Freshly isolated epidermal cells and cultured dermal papilla cells (DPCs) were mixed with various concentrations of activated PRP and transferred to a grafting chamber that was implanted onto the dorsal skin of nude mice. The chambers were removed 1 week after grafting, and HF formation was monitored for 4 weeks.

[RESULTS] We observed a significant difference (p < .05) in the number of newly formed follicles in the area of reconstituted skin (344 ± 27 with 10% PRP vs 288 ± 35 without PRP). PRP also shortened the time of hair formation significantly; the first hairs were observed in 18 ± 1 days using 10% PRP, versus 20 ± 1 days without PRP.

[CONCLUSION] A considerable effect of PRP on the time of hair formation and the yield of HF reconstitution was observed in this study. Considering the limited evidence available to judge its efficacy, further studies are required to investigate the mechanism of action of PRP.