A wound dressing comprises a sterile cell-growth supporting substrate comprising a crosslinked collagen conveniently in the form of a crosslinked collagen film disposes as part of a bilayer product upon a porous crosslinked or non-crosslinked collagen base. The collagen substrate carries epthelial cells, fibroblast cells or endothelial cells seeded on the substrate for example in the form of tissue fragments. The skin cells constitute preferably at least a sub-confluence cultured on a substrate and where a porous collagen is included in the substrate the substrate may contain an interstitial culture medium possibly in combination with interstitial growth hormone.
