Evaluation of matrix metalloproteinase inhibition by MI-Sorb Dressing for the treatment of chronic wounds
G.A. Skarja, R.K. Ho, A.L. Brown, M.H. May, M.V. Sefton, Rimon Therapeutics Ltd., Toronto, Ontario

Rimon Therapeutics develops synthetic therapeutic polymers (Theramers) that combine bioactivity with a broad range of desirable mechanical and physical properties. MI-Sorb Dressing is comprised of Rimon's novel MMP-binding MI Theramer beads contained within a medical-grade, porous nylon bag. The MI Theramer beads are designed to sequester matrix metalloproteinases (MMPs) from wound exudates, to promote healing of chronic wounds that exhibit elevated MMP levels. We have previously demonstrated that MI Theramer beads reduce model MMP solution activity in vitro and gelatin degradation in vivo.

We have conducted a series of pre-clinical quantitative assays for MMP activity in human chronic wound fluid using DQ gelatin-fluorescein. In addition, the reduction of specific MMPs relevant to chronic wounds (eg, MMP-8) was investigated using a variety of techniques (MMP colorimetric substrates and ELISA). Exposure to MI Theramer beads reduced gelatinolytic activity in human chronic wound fluid extracts by 80-90%. In addition, total MMP-8 concentration was reduced in wound fluid extracts. A pilot clinical study on MI-Sorb dressing is currently underway. The primary objective of the study is to evaluate the ablility of MI-Sorb Dressing to stimulate progress toward healing in chronic wounds. In addition, wound exudate MMP levels are quantified pre- and post-treatment to investigate the role of these tissue-destructive enzymes in non-healing wounds.