Inhibition of cell proliferation by chronic wound fluid

It has been proposed that occlusive wound dressings may enhance chronic wound repair by the stimulatory action of the fluid accumulating beneath the dressings. In this report, we investigated the in vitro proliferative effects of chronic wound fluid obtained from under a polyurethane membrane applied for 24 hours to venous ulcers in the ambulatory setting. By measuring cell counts and DNA synthesis, we found that chronic wound fluid inhibited the proliferation of human dermal fibroblasts (p = 0.008) and failed to stimulate the proliferation of microvascular endothelial cells (p = 0.03) and keratinocytes (p = 0.03). The inhibitory activity of chronic wound fluid on fibroblast proliferation was blocked after the fluid was heated to 100 degrees C, but not 56 degrees C, and was mainly restricted to a fraction of chronic wound fluid enriched in components less than 30 kd in molecular weight (p = 0.028). At concentrations ranging from 1% to 4% and in the presence of serum, chronic wound fluid decreased the viability of fibroblasts, as shown by a decreased ability of the cells to exclude trypan blue (p = 0.02), and the viability of endothelial cells, as shown by an increased release of tritiated adenine (p = 0.03). We conclude that the wound fluid obtained from beneath occlusive dressings applied to chronic wounds inhibits cell proliferation.