Thrombogenic surface

The cell layer lining blood vessels. It is now well established that endothelial cells not only maintain a non-thrombogenic surface in the blood vessels, but also... 

Thrombosis in stenosed human coronary arteries is one of the most common thrombotic diseases leading to unstable angina, acute myocardial infarction or sudden death. Treatment with angioplasty, thrombolysis, or bypass grafts can expose new thrombogenic surfaces and re-thrombosis may occur. The mechanisms responsible for this process include interactions of platelets with the damaged arterial wall and platelet aggregation. 

Ruggeri ZM. The role of von Willebrand Factor and fibrinogen in the initiation of platelet adhesion to thrombogenic surfaces. Thromb Haemost 1995 74 460-463. 

Using an arteriovenous shunt model of thrombosis in the rat, compounds 4 and 7 were evaluated for their ability to maintain patency of the extracorporeal circuit which serves as a thrombogenic surface [76]. Table 2 shows that on a gravimetric basis r-hirudin and inhibitor 4, were equipotent [r-hirudin EDis = 1.4 mg/kg 4 EDi5= 1.2 mg/kg i.v. bolus]. The thrombin inhibitor 7 was less effective in this assay having an EDi5= 6.3 mg/kg. 

In healthy blood vessels, resting platelets do not adhere to the non-thrombogenic surface of intact endothelium. However, platelets can adhere... 

Figure 9. Segmental surface experiments to test sensitization of blood due to contact with a thrombogenic surface (7). A, the apical section of the rod is coated with Silastic and the distal end is polypropylene and B, the apical section of the rod is polypropylene and the distal end is coated with Silastic.

Interest continues in the binding of heparin to polymers in an attempt to produce non-thrombogenic surfaces. This has been the aim in the use of glutaralde-hyde-protein complexes as coatings for latex rubber and polyurethanes. Glutaraldehyde has also been used to bind antibodies to partially hydrolysed polyamide surfaces for enzyme-linked radioassay techniques. One of the few examples of direct polymerization (as opposed to surface modification) in an attempt to produce polymers having improved compatibility involves the use of 2-methacryloyloxyethylphosphoryl choline in the formation of homopolymers and copolymers with methyl methacrylate. An isocyanato-urethane methacrylate has been synthesized from 2-hydroxyethyl methacrylate in connection with dental materials research in which the preparation of poly functional monomers for improvement of interfacial bonding with tooth tissue is a topic of some interest. 

Larm, O., Larsson, R., Olsson, R A new non-thrombogenic surface prepared by selective covalent binding of heparin via a modified reducing terminal residue. Biomater. Med. Devices Artif. Organs 11(2-3), 161-173 (1983)... 

Vascular grafts Nowadays, researchers are more interested in developing acceptable small-diameter vascular prostheses. The authors have designed small-diameter vascular prostheses, which include matrices with the ability to absorb growing anastomotic neointima. This property points out that a gelatin heparin complex, when adequately crosslinked, can simultaneously ftmction as a temporary anti-thrombogenic surface and as an excellent substructure for an anastomotic neointima... 

The findings shows that cultured endothelial cells can provide a non-thrombogenic surface, but only if problems of cell adherence to the substrate under flow conditions can be overcome. 

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