The SIS Wound Matrix (SISWM)* has recently been shown to improve healing of chronic leg ulcers over standard of care in a randomized clinical trial enrolling 120 patients.1 In a related investigation, we tested the hypothesis that chronic venous ulcers responsive to treatment with this biomaterial would more closely mimic an acute wound state as opposed to unresponsive ulcers. In a series of 12 patients randomized to the SISWM group during the clinical trial, serum and wound exudate were collected at baseline and at weekly intervals for up to 12 weeks. All patients received weekly applications of SISWM, and seven of the 12 patients eventually healed their wounds. Samples from all 12 patients were analyzed. Serum was examined for antibodies (total immunoglobulins) to the biomaterial, and wound exudates were analyzed for changes in matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP-9, and MMP-12), pro-inflammatory cytokines (IL-1beta, TNF-alpha, IL-8), and transforming growth factor beta (TGF-beta1). A variety of Th1/Th2 cytokines were also assayed. Results showed significant decreases in MMP-1, MMP-2, MMP-3, and MMP-9, significant decreases in TNF-alpha and IL-8, and significant increases in TGF-beta1 over time in wounds responding to SISWM treatment versus wounds refractive to treatment as verified using t-tests. None of the 12 patients formed a measurable serum antibody response to the SISWM. These data show that SISWM does not lead to immune system recognition when used to stimulate wound healing, and SISWM causes a shift to a more acute wound state for those wounds that do heal.

*Oasis Wound Matrix, Healthpoint, Ltd., Fort Worth TX.

Reference

1Mostow EN, Haraway GD, Dalsing M, Hodde JP, King D. Effectiveness of an extracellular matrix graft (OASIS Wound Matrix) in the treatment of chronic leg ulcers: A randomized clinical trial. J Vasc Surg 2005;41:856-862.