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

Abstract

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 10(6) 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.