Inflammatory response to a porcine membrane composed of fibrous collagen and elastin as dermal substitute

The inflammatory response to a collagen/elastin membrane was studied by mea suring the expression of cytokines and function associated antigens in huma n macrophages. Additionally the angiogenic and inflammatory activity in the chorioallantoic membrane of the chick embryo (CAM-assay) was investigated. Macrophages cultured on the membrane expressed IL-1 beta mRNA as early as after 4 hours. During prolonged culturing IL-1 beta mRNA levels decreased. Messenger RNA for IL-8 was detectable over the whole culture period. The an ti-inflammatory cytokine IL-10 was expressed up to one day only. Phenotypic analysis revealed a decrease in the number of chronic inflammatory 25F9 po sitive macrophages not migrating into the membrane but a presence of these cells together with the acute inflammatory 27E10 macrophages within the mem brane whereas the anti-inflammatory subtype RM3/1 was absent. In the CAM-as say the membrane stimulated angiogenesis and induced the formation of granu lation tissue. Histological analysis showed that the membrane was infiltrat ed with macrophages, fibroblasts and endothelial cells and locally with gra nulocytes. These data show that the collagen/elastin membrane causes activa tion of macrophages, angiogenesis and the formation of inflammatory tissue. Although these processes are essential for wound healing the type of infla mmation points to a chronic process which might counteract an efficient sca r formation. (C) 2001 Kluwer Academic Publishers.