Large surface of cultured human epithelium obtained on a dermal matrix based on live fibroblast-containing fibrin gels

The aim of this study was to develop a new keratinocyte culture system on a dermal, equivalent suitable for skin wound closure. Our dermal matrix is b ased on a fibrin gel from plasma cryoprecipitate containing live human fibr oblast (from human foreskin). Keratinocytes obtained from primary culture a ccording to the Rheinwald and Green method, were seeded on the gel at diffe rent seeding ratios. In all cases, the keratinocytes plated on the dermal e quivalent grew to confluence and stratified epithelium was obtained within 10-15 days in culture. Early expression of basal membrane proteins was dete cted by immunostaining with laminin and type IV collagen antibodies. Cell p roliferation was detected both in the epidermal layer and in the fibroblast embedded in the gel as assessed by BrdU incorporation. Detachment of compo site cultures from dishes or flasks is a simple and quick procedure without the need for dispase treatment. Grafting of composite cultures to nude mic e gave rise to an orderly stratified, orthokeratinized epithelium resemblin g human epidermis. A number of advantages including a large expansion facto r without the need of 3T3 feeder layer, the availability of fibrin/plasma c ryoprecipitate from blood banks and the versatile manipulation of composite cultures suggest that this system could be suitable for the definitive cov erage of severely burned patients. (C) 1998 Elsevier Science Ltd for ISBI. All rights reserved.