Characteristics and uses of biologic dressings and skin substitutes

Biologic dressings used for temporary coverage of open wounds exert both mechanical and physiologic effects by protecting the wound, maintaining microbial control, and hastening wound maturation. Synthetic wound dressings modeled after the biologic dressings have been evaluated by several investigators. Those studies have shown unilaminate synthetic membranes to be ineffective when applied to full-thickness wounds and have identified a bilaminate construction as being necessary for membranes to serve as effective skin substitutes. The desirable properties of skin substitutes have been identified and incorporated in the design of recently developed membranes. Recent studies in this and other laboratories have resulted in the development of collagen-synthetic bilaminates, a totally synthetic biologically inert bilaminate, and tissue culture-derived membranes. The characteristics and limitations of each skin substitute determine the optimum usage of these composite membranes and define the modifications needed to improve the effectiveness of such dressings.