Peripheral anchorage of dermal equivalents.

Human fibroblasts can induce collagen gel contraction with different kinetics depending on the number of cells and on the collagen concentration within this lattice, which has been considered as a dermal equivalent. Skin equivalent is a combined culture of dermo-epidermal layers which may be of therapeutic value in the treatment of burn patients. However, the current production of the dermal equivalent component gives results that present many drawbacks for their eventual clinical use as a first step in obtaining a skin equivalent. These include: (i) final surfaces which are very small; less than 20% of the initial size (ii) excessive thickness which may hamper successful graft take (iii) fibroblasts that do not have an arrangement comparable with normal dermal tissue. We propose, as a solution to these problems, the utilization of a 5-mm-wide fibre-glass filter ring peripherally attached to the surface of the Petri dishes to prevent inordinate contraction while the fibroblasts reorganize the collagen gel. Using this technique the initial surface was preserved and the dermal equivalent contracted only in thickness. Histological analysis of these anchored equivalents confirmed an alignment of fibroblasts and collagen fibres resembling normal dermal tissue. We consider this method useful in the development of dermo-epidermal sheets for clinical purposes.