Fibrinnetzwerk

Fibrinnetzwerk, or fibrin network, is the insoluble protein mesh that forms during blood coagulation. It provides the structural basis of a clot, traps blood cells, and seals a damaged vessel while supporting the early stages of wound healing. The network arises when thrombin cleaves fibrinogen to create fibrin monomers, which polymerize into fibrin strands. Factor XIIIa cross-links these polymers, stabilizing the mesh. Calcium ions and the surface of activated platelets promote polymerization and network formation, and platelets become embedded in the matrix to contribute to clot strength.

Structure and properties: The fibrin network is a three-dimensional, heterogeneous mesh with varying pore sizes and fiber thicknesses. These architectural features influence clot stability, permeability, and resistance to fibrinolysis. Clot architecture can differ between arterial and venous thrombi and is affected by fibrinogen concentration, thrombin generation, and the presence of platelets and red blood cells.

Function and dynamics: The fibrin mesh ensnares erythrocytes and leukocytes to form a hemostatic plug and serves as a provisional matrix for tissue repair. It also modulates local inflammation. Fibrinolysis, driven by plasmin generated after activation of plasminogen by tissue-type plasminogen activator, degrades the network to restore blood flow once healing progresses.

Clinical relevance: Abnormal fibrin network properties are linked to bleeding disorders, thrombosis, and coagulation abnormalities. Diagnostic methods such as thromboelastography assess clot formation dynamics influenced by the fibrin network. In research and medicine, fibrin networks are studied with microscopy and used as biomaterials in tissue engineering.