In vitro and in vivo testing of a collagen sheet to support keratinocyte growth for use as a burn wound covering.

Neonatal Fischer 344 rat keratinocytes were cultured on a collagen sheet to create a 'quasi-skin.' The cells were grown in either control medium or a low-calcium supplemented medium to enhance proliferation. The rate of 3H-thymidine incorporation into DNA was assessed at days 3, 7, 10, and 20 to determine the effectiveness of the medium supplements. The cells grown in supplemented medium did have an elevated rate of incorporation. On days 7 and 14 post culture, the quasi-skin was used to cover full-thickness defects on the dorsum of adult male rats. The covered defects were biopsied 45 and 60 days postoperatively. Light microscopy showed the wounds to be completely re-epithelialized. Barr bodies were present at the wound site, confirming the presence of quasi-skin keratinocytes up to 60 days postoperatively.