Lyophilized type-I collagen and chronic leg ulcers.

Lyophilized type I collagen (L.C.) can stimulate wound healing by recruiting a number of different cell types (i.e. platelets and macrophages) and proteins (i.e. fibronectin). Platelets and macrophages produce locally-acting growth factors that in turn induce fibroblast and epidermal migration, angiogenesis and increase matrix synthesis. Chronic leg ulcers (C.L.U.) are the end result of microvascular failure owing to ischemia and stasis. When L.C. has been used in the treatment of C.L.U. we have observed that: a) it is significantly more effective in stimulating the healing of chronic venous ulcers when compared to hydrocolloids (p less than .05), the two products being applied upon half of the same ulcer; b) in the treatment of C.L.U. due to arterial obstruction L.C. is more effective than hydrocolloids without achieving statistical significance; c) it is very effective in the treatment of C.L.U. in thalassaemic patients; d) telethermographic studies have demonstrated an increase of blood perfusion and histological studies have shown the stimulation of angiogenesis, fibropoiesis and epidermal growth; e) the application of L.C. determines the maximum obtainable increase also under conditions of proven cicatrization difficulty; and f) enzymatic degradation of L.C. has not promoted any bacterial infection and no local or generalized sensibilization phenomena have been observed. We can conclude that L.C. is a pharmacological approach to wound healing, directly interfering with cellular and non-cellular components, and significantly improves the reparative process when delayed.