Extracellular matrix analogs as carriers for growth factors: in vitro fibroblast behavior

Repair of connective tissue involves interactions between growth factors (GFs) and extracellular matrix (ECM) molecules. On the other hand, biological biomaterials could be used to carry and deliver GFs to stimulate wound healing. In the present study, fibroblasts were cultivated in a serum-free culture medium onto collagen (type I), hyaluronic acid, chondroitin sulfate, fibronectin, or fibrin. FGF, EGF, or PDGF was incorporated within those substrates. Using immuno- and radiolabeling assays, the distribution of GFs within the ECM analogs was relatively uniform and GFs retained in substrates were dependent on the substrates. Fibroblast replication was determined by the incorporation of [3H]-thymidine and compared to control groups. On collagen or chondroitin sulfate, the incorporation of GFs did not significantly improve cell proliferation. On hyaluronic acid, the incorporation of FGF and PDGF enhanced cell replication at 48 h. The incorporation of PDGF in fibronectin enhanced cell replication. On fibrin, the incorporation of PDGF, EGF, and FGF significantly enhanced cell replication. However, cell replication on FGF-incorporated fibrin was higher by 48 h than that on fibrin in the presence of FGF-supplemented culture medium. Fibrin sustains the biological activity of GFs, FGF in particular, and can be a carrier for GF that stimulates cell replication.