Collagen types in early phases of wound healing in children.

Small silicone rubber tubes containing a standard size viscose cellulose sponge (Cellstic) were implanted in wounds of ten children at the end of surgery. The Cellstics were drawn out of the wound 24--120 hours after implantation and the cellulose sponges were sectioned and studied for collagen types. Immunologically detectable Type III collagen and procollagen was detected in the sponges 24--48 hours after implantation whereas Type I collagen was not found at that time. From hour 72 onwards a substantial increase in Type I collagen was noted, while the relatively low levels of Type I procollagen remained unchanged. The levels of Type III collagen and procollagen increased only slightly. Primary cultures from 9-day-old granulation tissue synthesized preferentially Type I collagen, on the basis of chromatographic analysis. We conclude that Type III collagen is produced at the earliest phases of wound healing by primitive mesenchymal cells followed by the production of Type I collagen after the appearance of mature wound fibroblasts.