Markers of new blood vessels. (a), (d), (g) At each time point after surgery, positive expression (brown) of CD31 in Group A was most abundant. (b), (e), (h) In Group B, CD31 expression was lower than Group A, and the vessels were relatively small. (c), (f), (i) In Group C, CD31 was significantly lower than that in Groups A and B, with only trace expression. (j) Vessel density results. Scale bars: 100 μm. Group A was compared with Groups B and C, *P <0.05. Gel-C6S-HA, gelatin–chondroitin-6-sulfate–hyaluronic acid; HFSC, hair follicle stem cell; VEGF, vascular endothelial growth factor.