Model for phase III autografts of epidermal cells cultured on a collagen-proteoglycan biomatrix.

The primary aim of this study was to develop a model system that uses epidermal cells (keratinocytes and accessory pigmented cells) cultured on a reconstituted basement membrane biomatrix for use in conjunction with type I collagen as a replacement dermis-epidermis in the treatment of recurrent ulcerative lesions. Type I collagen sponges (Collistat) have been shown to promote rapid healing of leg ulcers but with extensive scarring (Reindorf et al, 1989). Dermatome sections from patients undergoing elective plastic surgery were treated with dispase to dissociate epidermis from dermis, the inner epidermal cells were then dissociated with trypsin-EDTA and plated on the biomatrix. A 4 cm2 skin specimen yielded approximately 10 to 12 million inner epidermal cells. These cells were plated at a density of 500,000 cells/cm2, thereby covering an area of 20 to 24 cm2. At 24 hours attached cells were dispersed primarily in monolayers, and by day 3 most of the epidermal cells reassociated into bi- or multilayered aggregates. Cells containing melanin granules were distributed in the basal to middle layers of the aggregates and persisted throughout the culture period (up to 14 days).