Background: Prolonged healing times and hypertrophic scarring of the donor site for split-thickness-skin grafts thicker than 0.3 mm are common problems that continue to challenge plastic surgeons in the clinic. As such, a human tissue-engineered epidermal membrane was constructed to promote wound healing and reduce scar hypertrophy.
Methods: An artificial allogenic epidermis was created in vitro using human keratinocytes and chitosan-gelatin membrane. Split-thickness skin graft donor sites were divided into three treatment groups: those covered with the combined keratinocyte/chitosan-gelatin membrane, those covered with chitosan-gelatin membrane only (control group), and those covered with traditional petroleum jelly gauze (blank group). The degree of wound healing was assessed at various time points after the operation by gross observation, hematoxylin and eosin staining, immunohistochemistry, and an assay of type I collagen using the picrosirius polarization method. Reverse-transcriptase polymerase chain reaction detection of the Y chromosome was also performed to distinguish between sexes.
Results: Over a 6-month observation period, treatment with the human tissue-engineered epidermal membrane (keratinocyte/chitosan-gelatin) appeared to decrease donor-site healing time (48 wounds in 24 cases). Average healing time was 8.1 +/- 1.3 days for the keratinocyte/chitosan-gelatin group, 16.4 +/- 1.7 days for the chitosan-gelatin group, and 22.9 +/- 4.2 days for the blank group. The artificial epidermis survived well and maintained a normal structure. Furthermore, hypertrophic scar formation was less severe for these wounds.
Conclusions: Keratinocyte/chitosan-gelatin membranes can be constructed in vitro and survive temporarily in vivo. They can be used to promote wound healing and reduce the severity of hypertrophic scarring of skin graft donor sites.