The isolated perfused porcine skin flap (IPPSF): I. A novel in vitro model for percutaneous absorption and cutaneous toxicology studies

This article describes the development of a novel in vitro alternative animal model for dermatology and cutaneous toxicology. A single-pedicle, axial-pattern, island-tubed skip flap was created in crossbred Yorkshire weanling pigs in one surgical procedure, then transferred 2 or 6 days later to a computer-controlled temperature-regulated perfusion chamber for 10- to 12-hr studies. Perfusate consisted of Krebs-Ringer bicarbonate buffer (pH 7.4) containing albumin and glucose. Viability was assessed by glucose utilization, lactate production, an absence of significant concentrations of the intracellular enzyme lactate dehydrogenase in the perfusate, and light and electron microscopy. A mean lactate to glucose ratio of 1.6 for flaps harvested 2 days after surgery and 1.8 for flaps taken 6 days after surgery suggested primarily anaerobic glycolysis. This preparation would be a humane alternative animal model for studies in cutaneous toxicology, physiology, oncology, and percutaneous drug absorption and metabolism.