Human skin histology as demonstrated by Herovici's stain: a guide for the improvement of dermal substitutes for use with cultured keratinocytes?

The potential for the widespread use of cultured keratinocytes for burns treatment is handicapped by practical problems such as fragility, poor take and, often, unsatisfactory cosmesis. Although dermal equivalents reduce these problems there remains a lack of consensus on what is the best structure of such equivalents. At present the commonest support is type I collagen. This histological study, however, using Herovici's stain, clearly shows that in human skin from a variety of anatomical sites the epidermis is not in direct contact with type I collagen but rather with a distinct layer of type III collagen. We suggest that dermal equivalents may have to be constructed so as to include a layer of type III collagen at the interface between the keratinocytes and a type I collagen neo-dermis, so mimicking normal skin structure more closely.