The microclimate chamber: morphological aspects of experimental deep burns treated topically with continuous humidified oxygen.

Scanning electron and transmission electron micrographs of tissue biopsies from experimental third-degree burns treated topically with 96% oxygen for twenty-five days, without modifying the environment of the whole animal, revealed a marked promotion of collagen maturation. The O2-treated wounds showed a high ratio of collagen-ground substance; assembling of distinct fibers to form bundles with individual fibers of 1,360 +/- 95 A in diameter and an organized orientation; a highly aggregated rough endoplasmic reticulum of the fibroblasts, consisting of large cisternae and abundant ribosomes. The control burn wounds exposed to ambient air exhibited a low ratio of collagen-ground substance; a loose, rough endoplasmic reticulum; fiber diameter of 700 +/- 70 A, with haphazard orientation of the fibers; and a poor tendency to form bundles. These findings suggest that topical treatment of experimental deep burns with 96% O2 promoted collagen maturation and organization as well as collagen synthesis.