Fibrin glues of human origin.

Wound healing is the response to injury and the process of tissue repair. Recent advances in cellular and molecular biology have greatly expanded our understanding of this process, which includes chemotaxis, production of matrix protein, cell replication, neovascularization and tissue remodelling. Tissue injury causes the disruption of blood vessels that is responsible for extravasation or haemorrhage of blood constituents and the first step of process in the platelet activation after exposure of collagen. Platelets initiate clotting through the coagulation system. When thrombin is formed, fibrinogen is transformed into fibrin; this is the real first step of wound healing. Fibrin glues reproduce this process and have been widely used in surgery to obtain haemostasis and expedite the process of wound healing. Immunogenicity of xenogenic products and risks of viral or prion disease transmission through commercial products have generated new interest in home-made autologous glues whose complexity was increased when platelets were added to coagulation proteins as a source of cytokines and growth factors. For the preparation of these products, the blood bankers took advantage of their usual technologies and several automated apparatuses are currently employed for the preparation of fibrinogen and thrombin concentrates. The machines for sequestration and multicomponent collection have been adapted for the concurrent procurement of plasma and platelets. A further level of complexity was introduced by the addition to glues of peripheral, bone marrow and cord-blood-derived stem cells to help or determine tissue regeneration. Instead of more new technologies, larger studies are now needed to quantify the benefits and clarify the optimal application for these products.