Keratinocyte allografts accelerate healing of split-thickness donor sites: applications for improved treatment of burns.

Grafting with split-thickness autograft skin remains the most effective method for treating burn wounds. When insufficient donor sites are present, decreasing the time required for healing of available donor sites permits more frequent reharvests to continue the grafting process. Cultured human keratinocytes speed wound healing by providing cover and by producing growth factors and extracellular matrix proteins. In this study we compare the rates of healing induced by allografts of cultured keratinocytes applied to split-thickness donor sites with healing by a standard treatment. Sheets of cultured human keratinocytes derived from neonatal foreskins are applied to a portion of a split-thickness donor site while the remainder is covered with a temporary skin substitute. The wound is inspected at 5, 7, 9, 11, 14, 17, 20, and 23 days. Biopsies are obtained at 7 days for light and electron microscopy. In 10 patients the average time to healing for sites covered with keratinocytes was 6.6 +/- 1.96 days compared with 12.6 +/- 4.32 days for control sites (p < 0.002). By day 7 most keratinocyte-covered sites showed reepithelization with the formation of a basement membrane and hemidesmosomes at the dermal-epidermal junction. Control areas were unhealed without epithelial coverage. The reepithelized donor sites from three patients treated with cultured keratinocytes were reharvested. In each case these grafts took, and they were equivalent to skin used from donor sites harvested for the first time. Keratinocyte allografts speed healing of split-thickness donor sites, thereby increasing the availability of autograft skin for burn wound coverage.