Wound fluids and the pathogenesis of chronic wounds

PURPOSE: To describe two areas of ongoing investigation into analysis of wound fluids that may eventually lead to better understanding of pathophysiology of chronic wounds and to improved care and treatment. METHODS: Studies used Lowry protein assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and zymography to analyze fluids from acute and chronic wounds and serum samples collected from healthy and affected volunteers. SUBJECTS: Thirty-one subjects with ages ranging from 32 to 79 years participated in the research; fluid was collected from chronic wounds in 10 patients (two female, four male, and four unrecorded), fluid was collected from acute mastectomy wounds in 15 patients (all female); blister fluid and blood were collected from two volunteers (one male, one female); and blood for serum preparation was collected from four volunteers (two female, two male). PRIMARY OUTCOME VARIABLES: (1) Fibronectin degradation and (2) expression of matrix metalloproteinases. RESULTS: Fibronectin can be degraded in fluid from chronic wounds but remains intact in blood-derived serum, plasma-derived serum, blister fluid, and mastectomy wound fluid. Matrix metalloproteinases are overexpressed in fluid from chronic wounds compared with mastectomy wound fluid, blood-derived serum, and plasma-derived serum. Matrix metalloproteinases are also expressed of somewhat higher levels in mastectomy fluid than in blood-derived and plasma-derived serum. CONCLUSIONS: These studies identified two factors that may contribute to delayed healing of chronic wound: fibronectin degradation and overexpression of matrix metalioproteinases.