Biological molecule-impregnated polyester: an in vivo angiogenesis study

Specific extracellular matrix molecules and growth factors (GFs) with angiogenic properties could be combined with biomaterials to enhance angiogenesis and subsequently tissue ingrowth through the wall of the porous structure. In this study, composite fibrin matrices containing hyaluronic acid (HA), fibronectin (FN) and/or fibroblast growth factor-1 (FGF-1), FGF-2 and an endothelial cell growth supplement (ECGS) were adsorbed onto Dacron meshes which were then implanted subcutaneously in mice. The release from the implants and the tissue distribution of implanted GFs were determined in vivo using radiolabelled FGF-2. Angiogenesis was quantified by counting the number of capillaries present in each Dacron histological serial section. Radiolabelled GF was rapidly released from matrices and was absent from them by day 28. A very low percentage of the implanted radiolabelled GFs was found in the kidneys and livers of the animals. The number of microvessels formed within fibrin-impregnated samples was increased in the presence of HA and ECGS at 14 d and of FN and ECGS or FGF-2 at 28 d. FGF-1 had no direct effect on angiogenesis in our model. These results indicate that enhancement of vascularization within prosthesis mesh may be achieved by using fibrin as a support for angiogenic molecules such as HA, FN and FGFs.