Reconstruction of epidermis on a chitosan cross-linked collagen-GAG lattice: effect of fibroblasts.

Reconstruction of epidermis on a fibroblast containing chitosan cross-linked collagen-GAG lattice at the air-liquid interface gives rise to a multilayered stratified epithelium, covered with a compact stratum corneum. Immunohistological studies reveal that the markers of epidermal differentiation are essentially distributed as in normal human skin and that the major proteins of the dermal-epidermal junction are present. Reconstruction of epidermis under identical culture conditions on a dermal equivalent that does not contain fibroblasts gives rise to an epithelium consisting of disorganized cell layers where the markers of differentiation are either displaced or not at all expressed, as in the case with filaggrin. In contrast, expression of the major constituents of the dermal-epidermal junction by the keratinocytes is completely independent of the presence of fibroblasts, even though it seems that the presence of fibroblasts is essential for the organization of the basement membrane proteins, creating a tight junction between dermal equivalent and the reconstructed epidermis.