For more than a century, the practice of dressing a wound has had as one of its major rationales the prevention of infection. Dressings can theoretically protect the wound from gross microbial contamination and help to prevent the spread of infection to other patients on the surgical ward. In this setting, one thinks of dressings as a barrier between the wound and the outside world. It is a relatively novel idea that the composition and properties of the dressing itself can play a major role in modifying the wound microenvironment. In the span of a decade, three key observations have helped physicians think of dressings as pharmacologic agents. Odland1 first observed in 1958 that a blister healed faster if left unbroken. Then, in a 1962 landmark article, Winter2 showed that occlusion of wounds with a polyethylene film (Polythene) more than doubled wound epithelialization in domestic pigs. Finally, Hinman