Thrombin-fibrinogen solution

This is a dry sponge of human fibrin prepared by elotting a foam of human fibrinogen solution with human thrombin. It is then freeze-dried, cut into shapes and sterilized by dry heat at 130°C for 3 hours. Before use, it is saturated with thrombin solution. Blood coagulation occurs in contact with the thrombin in the interstices of the foam. 

When thrombin is added to fibrinogen in an appropriate buffer the fibrinogen solution is converted to a fairly rigid gel, the fibrin clot. The reaction of interest may be written, for the moment, as... 

Fig. 92. Electron micrograph of bovine fibrin, clotted by the addition of thrombin to a fibrinogen solution, and stained with phosphotungstic acid. Ma ification 80,000 (Hall, 1949).

Fabrication of the new 3 dimensional scaffold was by mixing the two materials in different compositions (Table 1). The Fibrin gel was formed by injecting a mixture of 50 mg/ml of HAM and 50 mg/ml of fibrinogen suspension with 10 U of thrombin-CaCli solution simultaneously into a 70 mm x 50 mm custom made 316L mold (Figure 2). The mold was incubated for 45 minutes in the incubator (37° C, 5% CO2) before the transfer of the formed construct to a 24-weU plate (Figure 3). 

The standard method for seeding cells was followed by mixing the cells into the optimized fibrinogen-HAM ( ) suspension with Thrombin-CaCli solution. The cells were seeded at a density of 3-5 x 10 cells per mold construct. The construct was observed and analysed at day 7 and 14. 

In this chapter, we study the ability of water-soluble dihydroquercetin derivative to inhibit ozone oxidative modification of fibrinogen. Assessment of functional activity of fibrinogen both before and after oxidation with ozone was conducted by determining the time of formation of a fibrin clot after addition of thrombin to fibrinogen solution. Recently, we have evaluated the ability of native dihydroquercetin to inhibit ozone oxidation of fibrinogen. In this chapter, we found that the new water-soluble dihydroquercetin derivative is more potent in preventing the oxidative modification of fibrinogen in comparison with native dihydroquercetin. 

PLASMA. The portion of the blood remaining after removal of the white and red cells and the platelets it differs from serum in that it contains fibrinogen, which induces clotting by conversion into fibrin by activity of the enzyme thrombin. Plasma is made up of more than 40 proteins and also contains acids, lipids, and metal ions. It is an amber, opalescent solution in which the proteins are in colloidal suspension and the solutes (electrolytes and nonelectrolytes) are either emulsified or in true solution. The proteins can be separated from each other and from the other solutes by nltrafiltration, nltracentrifugation, electrophoresis, and immuno-chemical techniques. See also Blood. 

It is noteworthy that a qualitatively similar dependence was observed for heparin in solution116>. The complexes of immobilized heparin with fibrinogen and thrombin are rather stable (the corresponding association constants for the complexes with fibrinogen and thrombin are (1.4 0.5) x 105 M and (8 2) x 10s A/-1) and are not subjected to dissociation in physiological solution. 

Hence, concerning the interaction with plasma proteins, covalently immobilized heparin performs identically to heparin in solution, and this results in the enrichment of the HCP surface with the most thrombogenic plasma components fibrinogen and thrombin. 

Place syringe with fibrinogen/thrombin solution in a shaker for 30 min. 

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