Methods: Normal human fibroblast were incorporated within a collagen gel and gradually formed a tissue, the dermal equivalent (DE). The dressings were applied on the DE, and the culture meium were analyzed. In particular MMP-2 and -9 (Gelatinases), MMP-3 (Stromelysin) or MMP-1 and -8 (collagenases) were detected using zymography techniques with gelatin, casein and collagen gels, respectively.
Results: The inhibitory effects of NOSF were time-dependent and dependent on the MMPs analyzed. In particular MMP-2 was clearly inhibited at day 4 by NOSF compared to results at days 2 and 8. On the contrary, for MMP-9 the inhibition by NOSF was progressive and reached a peak at day 8.
Conclusions: Application of a lipidocolloid dressing impregnated with NOSF on a dermal equivalent model made it possible to study in vitro, but the the tissue level, the mechanisms of action of this dressing on human cells, in a close in vivo situation. This characterization of the inhibitory effects of this wound dressing matrix on MMPs, contributes to to explain the efficient results onserved in vivo on wounds at risk of delayed healing.