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 ma ny other groups. Since their postgrafting survival time is limited, th e effect of these cultures is generally explained by the production of wound repair-stimulating factors that promote proliferation and migra tion of resident cells. III this study we show that lysates of culture d keratinocytes contain mitogenic activity for keratinocytes, endothel ial cells, and fibroblasts. In addition, the lysates inhibit the contr action of collagen gels by human skin fibroblasts. On the basis of the se observations and of in vivo data obtained by ourselves and others, we have evaluated the effect of total keratinocyte lysates on the heal ing of meshed skin autograft-covered burn wounds. Twenty burn wounds w ere tangentially excised and autografted with one to three meshed conv entional skin transplants. An area treated with a gel containing lysat ed keratinocyte cultures was compared with an area treated with placeb o-gel in terms of epithelialization on day 5. In six patients an addit ional fresh keratinocyte alloculture was applied as a positive control . Results indicate that the newly formed epithelium (difference betwee n percentage of epithelialization on day 5 and on day 0) was 31.1 perc ent 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 s how a twofold stimulation of epithelialization.