Cultured subconfluent keratinocytes on wound polymer dressings in the treatment of burns and chronic wounds

Background: Conventional treatment of deep or full-thickness burn wounds is achieved by using split-thickness skin autografts (STSG) as wound coverage . However, disadvantages of this method include donor site morbidity (scarr ing) and limited donor sites in extensive burns. Hence numerous skin substi tutes have been developed, an example of which is cultured keratinocyte she ets. These are of limited clinical usefulness as the process is time consum ing and labor intensive, cell viability is pear, and the keratinocyte sheet s are fragile and difficult to handle. Culturing subconfluent keratinocytes on a delivery system avoids some of these disadvantages. Subconfluent kera tinocytes are proliferative, active, and produce growth factors that promot e wound healing. The use of polymers, on which the cells are cultured and t ransferred, improves the ease of handling and transfer of the keratinocytes . A transparent polymer also allows observation of cell growth and of wound healing status. Methods: We report on techniques that we have developed fo r culturing keratinocytes on commonly available medical polymer dressings. In pilot clinical studies, keratinocytes cultured on a wound polymer dressi ng were used to treat two full-thickness wounds, two partial-thickness burn s, four STSG donor sites, one chronic wound, and one full-thickness burn gr afted with widely meshed STSG ('sandwich' graft). Results: We noted good vi ability and growth of cells cultured on the polymer dressing. In full-thick ness burns, we observed islands of epithelialization beneath the polymer me mbranes suggesting migration and 'take' of the cultured keratinocytes. In p artial-thickness burns and STSG donor sites, more rapid epithelialization w as observed compared with controls treated conventionally. In the chronic w ound we observed successful healing of the wound that failed to heal with c onventional treatment. Conclusions: The results suggest that subconfluent k eratinocytes cultured on polymer dressings may be effective in the treatmen t of acute and chronic wounds. Further studies are needed to confirm this.