[SCREENING ASSESSMENT OF MATERIALS THROMBOGENICITY BY THE NUMBER OF PLATELETS ADHERED FROM THE FLOWING NATIVE BLOOD]

The materials used in the construction of implants contacting with blood should be resistant to thrombus formation. One of the stages of a thrombogenicity assessment of materials is to determine the number of platelets adhered to its surface during the exposure to flowing blood under ex viAvo conditions. The aim of this study was to develop a modified test for screening assessment of materials for their thrombogenicity in contact with native blood. For the purpose of the study, flow chambers of were developed, allowing to mountain simultaneously 16 material samples. The chamber was connected to the circulatory system of the experimental animal through arterial and venous ports in such a way that blood, passing through the chamber, returned to the animal. The exposure time was 1 min. After perfusion the samples were rinsed and stained. The number of platelets adhered per unit area was calculated automatically that allowed significant error diminution. A total of 9 experiments were carried out on pigs under ex vivo conditions. The method was validated using standard samples of pyrolytic carbon, VT-6 titanium, glass, and polytetrafluorethylene as reference materials. New materials for synthetic vascular prostheses have been investigated. The developed technique makes it possible to study the thrombogenicity of polymeric materials with sufficient reliability.