Cultured epidermal allografts as biological wound dressings

Recent advances in cell culture technology permit the generation of large stratified epithelial sheets appropriate for wound coverage. Autografts (sheets prepared from the patient's own skin) have proven life-saving in the treatment of large third-degree burns and have been successfully employed in the management of chronic ulcers. Allografts (sheets prepared from the skin of an unrelated donor) have also been used. In our experience, cultured allografts derived from neonatal foreskin provide a potent stimulus to healing in a variety of partial thickness wounds. Their application is a simple outpatient procedure which involves no discomfort for the patient. In contrast to autografting, no biopsy is necessary and use of cultured allogenic cells permits immediate grafts availability and possibility of stockpiling and preserving grafts for future use. Preparation of epithelial sheets suitable for grafting is also faster and easier with newborn than with adult donor cells. Newborn allografts have caused rapid healing of most previously refractory ulcers with long-term results comparable to those obtained with conventional split thickness grafting. We postulate that cultured allografts act by providing a temporary wound covering while releasing multiple cytokines that synergistically promote permanent reepitheliazation by previously quiescent host keratinocytes then stimulated to divide and migrate. Whether allografts are immunologically rejected in a clinically undetectable reaction or simply replaced stochastically by host keratinocytes is presently unknown.