Proteolytic activity in wound fluids and tissues derived from chronic venous leg ulcers

Venous leg ulcers affect approximately 1% of the general population and 3.6% of those over the age of 65. The goal of the research described herein is to shorten the time to healing by developing wound care alternatives that are based on a comprehensive understanding of the venous ulcer wound environment. The proteolytic and inflammatory components in wound fluids and tissue biopsy samples were characterized in subjects with documented long‐standing venous ulcers that had showed resistance to standard therapy. All wounds showed polymicrobial colonization with greater than 106 CFU/g. Myeloperoxidase, a measure of leukocyte infiltration, was also markedly elevated in these wounds. Zymography revealed the presence of both pro‐matrix metalloproteinase (MMP)‐2 and pro‐MMP‐9 in wound fluids and to a lesser extent in tissue biopsies. Using an immunocapture activity assay we reveal a sevenfold excess of MMP‐9 in wound fluid as compared to tissue, with 73% in the activated form. In contrast, MMP‐8 total protein levels were nearly equal in wound fluids and biopsies. Fibronectin, a critical component of the extracellular matrix, was shown to be degraded in both wound fluids and biopsy samples. Finally, the potential of a novel wound dressing to neutralize several constituents of this hostile wound environment is shown.