The growth of human keratinocytes on human acellular dermis in 4 different culture systems was compared. Epidermis was completely separated and removed from dermis after skin samples had been soaked in 0.1% trypsin at 4 degrees C for 1 week. Forty pieces of saline-washed dermis, 1 cm2 each, were randomized into 4 groups: in group A, human keratinocytes that had undergone 2 to 3 cell passages were seeded (30 x 10(4) cell/cm2) onto the dermis and sprayed with a thin layer of fibrin glue and proliferative 3T3 feeder cells that had been growing separately on the culture dish; in group B, the dermis was only sprayed with fibrin glue; in group C, the dermis was treated with 3T3 cells only; and in group D, the dermis was not sprayed with anything. The dermis samples in all groups were raised on a grid to provide an air-liquid culture system. Histology results of the composite grafts at 2 weeks were assessed as having either scanty colonies of keratinocytes (SCK), continuous stratified epithelium (CSE), or no observable keratinocyte growth. Eight out of the ten dermis samples (80%) in group A demonstrated CSE, and 30% of the samples in group B showed SCK. There were 10% SCK and 20% CSE in group C, and in group D, 30% SCK and 10% CSE were found. The good results in group A indicated that the fibrin glue facilitated the seeding efficiency of the keratinocytes on the dermis and that the vital factors released from the 3T3 feeder cells enhanced the growth and differentiation of the keratinocytes. This model provides an optimal system for the cultivation of keratinocytes on acellular dermis.