HEPARIN-FIBROBLAST GROWTH FACTOR-FIBRIN COMPLEX - IN-VITRO AND IN-VIVO APPLICATIONS TO COLLAGEN-BASED MATERIALS

Biological molecules such as fibrin and growth factors could have inte resting features to design bioactive biomaterials and particularly col lagen-based materials used as connective tissue replacement. Different combinations of fibroblast growth factor (FGF) and heparin complexed to fibrin were analysed. In vitro, FGF bound to matrix was rapidly, bu t partially released, specifically with heparin. Heparin concentration s were progressively equilibrated between matrix and medium. DNA repli cation of fibroblasts grown either on or within fibrin matrices was in creased in the presence of both FGF and high doses of heparin incorpor ated in fibrin. Subcutaneous implantations of collagen sponges impregn ated with composite fibrin matrices showed qualitative and quantitativ e tissue ingrowth within the sponges. The uncross-linked collagen of f ibrin-impregnated sponges swelled after implantation. The resulting fi broblast-infiltrated tissue resembled a normal dense connective tissue that was observed particularly in the presence of high doses of hepar in and FGF incorporated in fibrin.