Thrombin and fibrinogen powders are the active components of advanced surgical

Thrombin and fibrinogen powders are the active components of advanced surgical hemostasis products including the EVARREST Fibrin Sealant Patch. PF 431396 inside a coagulometer to determine the thrombin activity of the original powder. Samples coated with powders comprising fibrinogen and varying amounts of thrombin were tested using the method explained herein. The results demonstrated that the method could consistently measure the activity of (alpha) thrombin in the presence of fibrinogen PF 431396 over a broad range of thrombin activity levels. The test was successfully validated relating to International Conference on Harmonization of Complex Requirements for Sign up of Pharmaceuticals for Human being Use Guidelines PF 431396 and thus is suitable for use as part of a commercial developing process. A method has been developed that enables thrombin activity to be measured in a mixture of fibrinogen and thrombin powders. Keywords: alpha thrombin analytical screening clotting assay EVARREST EVICEL fibrin sealant fibrin sealant patch fibrinogen haemostasis thrombin activity Intro Fibrinogen and thrombin are crucial proteins involved in achieving hemostasis after vascular injury and are essential for fibrin clot formation. In response to cells injury and disruption of the vascular endothelium thrombin a serine protease derived from its inactive precursor prothrombin is definitely generated. In addition to its main part in fibrin clot formation thrombin is definitely a PF 431396 central mediator in a wide range of biochemical processes including modulation of vasoconstriction coagulation and fibrinolysis platelet activation fibrin stabilization and cells restoration [1 2 Thrombin is used only or in combination with additional hemostasis products to induce local hemostasis and control bleeding during numerous surgical procedures. Fibrinogen and thrombin can be combined in dry form without initiating Rabbit Polyclonal to MCPH1. a typical clotting reaction. Products comprising these proteins in dry form have a variety of potential biomedical applications including topical hemostasis cells repair drug delivery etc. A significant benefit of these products is definitely that they can become stored at space temperature and don’t require thawing reconstitution or device loading so they are ready to use immediately when needed and well suited for use in emergent situations [3]. EVARREST Fibrin Sealant Patch is an example of such a product. EVARREST is composed of dried unreacted fibrinogen and thrombin powders coated onto a composite matrix consisting of polyglactin 910 (i.e. same natural material as found in VICRYL family of sutures and mesh products ETHICON Inc.) and oxidized regenerated cellulose (ORC). The structure of EVARREST is definitely illustrated in Fig. ?Fig.1 1 and an image of the biologic powder-coated part of the product is shown in Fig. ?Fig.2.2. EVARREST is definitely indicated for use with manual compression as an adjunct to hemostasis for control of bleeding during adult liver surgery and smooth cells bleeding during open retroperitoneal intra-abdominal pelvic and noncardiac thoracic surgery in adults when control of bleeding by standard surgical methods of hemostasis (e.g. suture ligature and cautery) is definitely ineffective or impractical [4]. Fig. 1 Structure of EVARREST Fibrin Sealant Patch. Fig. 2 EVARREST Fibrin Sealant Patch. When the product is definitely applied to a bleeding site the proteins are hydrated resulting in the conversion of fibrinogen to fibrin forming a fibrin clot which adheres the Fibrin Sealant Patch to the cells and promotes hemostasis. The fibrin clot is definitely integrated into the matrix which provides mechanical support and strength to the clot. EVARREST has been shown to be superior to the standard of care (SURGICEL Initial Absorbable Hemostat) in soft-tissue bleeding control and is safe and effective as an adjunct for rapidly and reliably achieving hemostasis for soft-tissue bleeding during surgery [5]. The ability to measure and control thrombin activity is critical to the features of EVARREST and additional products containing dry fibrinogen and thrombin. Typically measurement of thrombin activity is performed by a standard enzyme-substrate type reaction where conditions are carefully controlled such that the pace of conversion of substrate (fibrinogen) to product (fibrin) is dependent upon enzyme concentration [6]. In an aqueous medium thrombin will cleave fibrinopeptides A and B from fibrinogen resulting in fibrin monomers. These monomers will.