THE ENHANCEMENT OF CELLULAR INFILTRATION AND VASCULARIZATION OF A COLLAGENOUS DERMAL IMPLANT IN THE RAT BY PLATELET-DERIVED GROWTH-FACTOR BB

The implantation of collagen-based dermal substitutes offers one means of management of full-thickness skin lesions, We have examined the ef fect of the recombinant BE homodimer of platelet-derived growth factor (rPDGF-BB) on the extent of cellular infiltration and vascularisation of collagen sponges implanted into full-thickness excision wounds in rats. Histological examination of sponges excised 14 and 21 days post- implantation in dose-response studies in which 0-4 mu g rPDGF-BB were applied to the undersurface of each sponge, immediately prior to its i mplantation, demonstrated a progressively increased infiltration of ho st cells, especially fibroblasts, and enhanced capillary formation. Wi th 4 mu g rPDGF-BB, an enhanced infiltration of fibroblasts into spong es was already apparent 3 days postimplantation, and enhanced capillar y formation was noticeable after 7 days. This neovascularisation was n oted to be associated with improved survival of autologous split-thick ness skin grafts applied to the sponges immediately following their im plantation.