Effect of PRP on the proliferation of dermal papilla cells and hair follicle regeneration in mice / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of platelet-rich plasma (PRP) on the proliferation of dermal papilla cells (DPCs) and hair follicle regeneration.</p><p><b>METHODS</b>PRP was prepared using the double-spin method and applied to DPCs. The proliferative effect of activated PRP on DPCs was measured using MTT assay. To understand the influence of activated PRP on the hair-inductive capacity of DPCs, freshly isolated epidermal cells and DPCs of passage 4 were resuspended, mixed with various concentrations of a PRP (0%, 5% or 10%) and were then transferred to a grafting chamber, which 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; the graft site was harvested and processed for histological examination.</p><p><b>RESULTS</b>Activated PRP increased the proliferation benefited the aggregative growth of DPCs. There are significant difference in the yield of hair follicles compared with 10% PRP (344 +/- 27) with 0% PRP (288 +/- 35) in the area of reconstituted skin (P < 0.05). The areas treated with PRP demonstrated an increase in hair follicles density of 19.4%. Ten percent PRP (18 +/- 1) d also can significantly shorten the time of hair formation, compared with 0% PRP (20 +/- 1) d (P < 0.05).</p><p><b>CONCLUSIONS</b>There is a considerable effect of PRP on the time of hair formation and the yield of hair follicles reconstitution.</p>

Implantation of newborn mice skin cells with chamber method to construct a model of hair follicle development / 中华整形外科杂志

<p><b>OBJECTIVE</b>To construct a convenient, reliable and visual model of hair follicle development to test the hair-inductive potential of follicular cells and investigate the molecular mechanism regulating hair follicle morphogenesis and cycling.</p><p><b>METHODS</b>An open chamber was transplanted into the nude mice dorsal skin, dermal and epidermal cells isolated from newborn C57BL/6 mice skin were mixed at a specific ratio and then injected into the chamber together, 1 week after transplantation, the chamber was removed, and then, hair formation and regeneration after hair plucking was observed.</p><p><b>RESULTS</b>1 week after cells implantation, the wound was moist without apparent contraction and among that pink and translucent tissue was formed. 2 weeks after implantation, the wound healed completely. 3 weeks after implantation, black hair grew from the skin was observed. 4 weeks after implantation, thick and black hair grew from the skin vertically. Completely developed structure of hair follicle was observed with paraffin section and HE staining. 1 week after plucking, new hair had regrown. The ratio of cell component was varied, whereas the other component was fixed at 1 x 10(7) cells. When the number of epidermal cells was reduced to 1 x 10(6) cells, the efficiency of hair follicle reconstitution was mostly unchanged. On the other hand, the density of newly formed hair was diminished considerably by reducing the number of dermal cells to 5 x 10(6) cells or lower. Neither epidermal cells nor dermal cells transplanted alone formed hair follicle.</p><p><b>CONCLUSIONS</b>Newborn mice skin cells transplanted by chamber method can construct a complete model of hair follicle development, which can be used to test the hair-inductive potential of follicular cells and investigate the molecular mechanism regulating hair follicle morphogenesis and cycling.</p>