OBJECTIVETo investigate the feasibility of fabricating tissue engineering skin with human hair follicle bulge cells (HFBCs) to repair full-thickness skin wound.

METHODSHFBCs and dermal papilla cells (DPCs) isolated from human fetal hair follicles by collagenase digestion were cultured, purified and passaged. PGA-collagen scaffolds as bioengineered dermis were randomly divided into A and B groups. The HFBCs and DPCs (1 : 2) were seeded in scaffolds of group A and the equal amount of DPCs was seeded in scaffolds of group B as control. Then the keratinocyte sheets were seeded onto the surfaces of the scaffolds as bioengineered epidermis. The tissue engineering skins were then transplanted to repair the full-thickness wound on the back of nude mice. The wound healing process was observed and the plant histological changes of the transplanted engineered skin was observed with light microscope on 2, 4, 6 post-operation weeks (POW).

RESULTSThe full-thickness defect of nude mice in A and B groups could be effectively repaired by bioengineered skins. On 2 POW, integral epidermal and dermal structures were observed in the wounds in A and B groups, with thin epithelial layer and basement membrane. On 4 POW, epithelial layer became thickening and rete pegs formation was observed in basement membrane in A group, but only thickening of epithelial layer was observed in B group. On 6 POW, rete pegs structure was seen to descend and hair-follicle-like structure was formed, while only thickened epithelial layer with flat basement membrane were formed in B group.

CONCLUSIONFrom the composite skin engineered with PGA-collagen hybrid scaffolds and keratinocytes, HFBCs and DPCs could effectively repair the full-thickness skin defect of nude mice. The hair follicle stem cells participate in the process of anatomic repair of wound, and might be able to induce the repair of skin structure and function.