Stabilized autologous fibrin-chondrocyte constructs for cartilage repair in vivo

Stabilization of fibrin-chondrocyte constructs with fibrinolytical inhibitors has been shown to be a feasible method for the reconstruction of cartilage in vitro. In this study, the method was tested in vivo. Autologous cultures were used to form stabilized fibrin-chondrocyte constructs that were injected into auricular cartilage defects of rabbits. Stabilization was achieved by high doses of fibrinolytic inhibitors. Samples were prepared for magnetic resonance imaging, histology, and immunohistochemistry after 1, 2, 4, and 6 months. Defects of the contralateral ear, which were treated with stabilized fibrin without cells, were used for controlled comparisons. In all cell-fibrin samples, cartilage-like tissue was present. Immunohistochemistry revealed the presence of collagen II. This finding was similar for all observations. In the control samples, only minor new cartilage could be detected at the cut edges. The reconstruction of cartilage in vivo by injecting fibrin-chondrocyte constructs, stabilized with inhibitors of fibrinolysis, is thus possible.