Lyophilized keratinocyte cell lysates contain multiple mitogenic activities and stimulate closure of meshed skin autograft-covered burn wounds with efficiency similar to that of fresh allogeneic keratinocyte cultures.

For several years, grafting with allogeneic keratinocyte cultures has been used successfully as a wound-healing therapy both by us and by many other groups. Since their postgrafting survival time is limited, the effect of these cultures is generally explained by the production of wound repair-stimulating factors that promote proliferation and migration of resident cells. In this study we show that lysates of cultured keratinocytes contain mitogenic activity for keratinocytes, endothelial cells, and fibroblasts. In addition, the lysates inhibit the contraction of collagen gels by human skin fibroblasts. On the basis of these observations and of in vivo data obtained by ourselves and others, we have evaluated the effect of total keratinocyte lysates on the healing of meshed skin autograft-covered burn wounds. Twenty burn wounds were tangentially excised and autografted with one to three meshed conventional skin transplants. An area treated with a gel containing lysated keratinocyte cultures was compared with an area treated with placebo-gel in terms of epithelialization on day 5. In six patients an additional fresh keratinocyte alloculture was applied as a positive control. Results indicate that the newly formed epithelium (difference between percentage of epithelialization on day 5 and on day 0) was 31.1 percent in the treated area compared with 16.5 percent in the placebo area. This result is comparable with the value obtained by treatment with fresh keratinocyte allocultures, namely, 33.8 percent. These figures show a twofold stimulation of epithelialization.