Inhibition of basal cell proliferation during storage of detached cultured epidermal keratinocyte sheets

Grafting of human cultured keratinocytes is a promising possibility for the treatment of large burned skin areas. However, during the preparation of cultures for grafting, a necessary step of detachment from culture substratum is performed by incubation with Dispase. In the present paper, we report studies performed to determine whether prolonged storage after detachment would have a detrimental effect on keratinocyte proliferation. Our results show that the number of bromodeoxyuridine-incorporating cells located in the basal layer of the culture gradually diminishes during storage of detached cultured epidermal keratinocyte sheets. Furthermore, the rate of [3H]thymidine incorporation in such detached cultures is also progressively reduced. These observations indicate that the detachment and storage of cultured epidermal keratinocyte sheets for grafting impedes their cell proliferation capacity, as revealed by DNA-synthesis measurements.