IN-VITRO EFFECTS OF EXTRACELLULAR-MATRIX AND GROWTH-FACTORS ON ENDOTHELIAL-CELL MIGRATION AND VESSEL FORMATION

Specific extracellular matrix and growth factors appear to control cap illary endothelial cell behavior. In addition, fibrin clot that occurs after injuries is the primary matrix for endothelial cells. In the pr esent in vitro study, endothelial cell growth supplement (EGGS) and va rious concentrations of fibronectin (FN) or hyaluronic acid (HA) were combined to a fibrin matrix model in which capillary endothelial cells were seeded. Growth factor distribution was controlled by autohistora diography that demonstrated uniform distribution. Sensitivity of fibri n matrices to fibrinolysis was assayed using plasmin. Low and moderate concentrations of HA or FN significantly increased migration of cells , at a higher degree in the presence of EGGS, and decreased the length and diameter of tubes. Migration distance was particularly increased in the presence of moderate concentrations of FN and EGGS, while a hig h concentration of FN reduced migration distance. In the presence of b oth EGGS and a high concentration of FN or HA, tubes observed were lar ger than those at lower concentration. The presence of these biologica l molecules can modify endothelial cell migration and capillary format ion in a fibrin clot. The fibrinolytic characteristics of the fibrin n etwork could participate in the formation of microvessels.