Wounds clotting process

Fibrin is the major protein component of blood clots and is formed by enzymatic cleavage and polymerization of fibrinogen. Because of its important role in natural wound healing process, fibrin is an attractive functional material for tissue engineering. Additional... 

Fibrin is a biopolymer similar to collagen. It is an important component of the namral blood clotting process. Fibrin has long been used as a biopolymer due to its excellent biocompatibility and rapid bioresorption. It is widely used as a sealant to induce thrombosis and prevent blood loss from wounds. Fibrin also facilitates cell adhesion and proliferation. 

Platelets are anucleate cell fragments that bind to damaged tissues where they are instrumental in the blood clotting and wound-healing processes. Megakaryoblasts and megakaryocytes are multinucleated... 

Debridement refers to the process of cleaning a wound by removal of foreign material and dead tissue. Cleansing of the wound facilitates rapid healing and minimizes the risk of infection due to the presence of bacteria at the wound surface. The formation of a clot, followed by a scab, on a... 

During platelet plug formation, the fibrinolytic pathway is locally activated. Plasminogen is enzymatically processed to plasmin (fibri-nolysin) by plasminogen activators present in the tissue. Plasmin interferes in clot propagation and dissolves the fibrin network as wounds heal. At present, a number of fibrinolytic enzymes are available for treatment of myocardial infarctions or pulmonary emboli (see p. 201). 

As a result of the contact of blood with none-ndothelial surfaces, several humoral and cellular systems can be activated. Exposure of blood proteins and cells to blood contacting medical devices can activate plasma proteolytic systems (coagulation (blood clotting system), fibrinolysis (process by which clot is broken down), complement cascade (a system of soluble proteins involved in microbiocidal activity and the release of inflammatory components), Kallekrein-kinin and contact systems) and at least three cellular elements (leukocytes, endothelial cells, and platelets). Contrary to the normal situations whereby these mechanisms are localized and intended to promote wound healing, activation of these systems by medical devices can result in nonlocalized systemic reactions. The preclinical and clinical assessments of hemocompatibility are designed to minimize modification of these systems. 

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