Fibrin plays a critical role in prevention of bleeding and restoration of wounded tissue by providing a matrix for cellular and macromolecular interaction. The complex structure of fibrin provides for unique interactions with blood-derived and interstitial-tissue derived macromolecular components which play critical roles in supporting fibrin's overall biological functions. The integrated role of fibronectin, thrombospondin, and other matrix adhesive glycoproteins as well as transglutaminases with fibrin in prevention of bleeding and wound healing will be presented.