Extensive skin loss from a variety of conditions is associated with si
gnificant functional morbidity and loss of life. In many patients, a l
imited number of donor sites available for harvesting autologous split
-thickness skin grafts prevents early, effective, and permanent wound
closure. In the past 25 years, significant biotechnological advancemen
ts have been made in defining the criteria and manufacturing ingredien
ts in materials that could serve as skin replacements for permanent wo
und closure. The optimal skin replacement should have the functional a
nd cosmetic properties of the dermis and the epidermis. It should prov
ide rapid, functional wound coverage and barrier protection to microor
ganisms, normalize fluid flux and hypermetabolism, and provide long-te
rm stability without contraction or hypertrophic scarring. In addition
, the optimal skin replacement should be nontoxic, easily stored and u
sed, and relatively cost-effective. This report will discuss the two m
ajor skin replacement designs available today, cultured keratinocyte g
rafts and bioartificial bilaminate systems, outline the advantages and
disadvantages of each material, report the results of clinical trials
for each, and speculate on the potential for each material to serve a
s a practical skin replacement.