Regulating blood cell adhesion via surface modification of polyurethanes

Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, 

RWTH Aachen University, PauwelsstraBe 20, Aachen, Germany 

Copyright 2016 Johanna Qauser. Published by Elsevier Ltd, All rights reserved. 

The following sections focus on both the chemical and the physical modification of PUs, summarize the different approaches, and highlight similarities as well as differences. Therefore, a short overview regarding blood-material interactions and the impact on medical devices is given first, followed by an explanation of surface-liquid interactions. 

The extrinsic path is a direct consequence of the endothelium injury and is thus initiated by the so-called tissue factor (Factor HI). This is followed by the activation of other coagulation factors, such as Factor Vn and Factor IX, which are additionally triggered and intensified by calcium (Ca +), leading to the activation of Factor X. The activated Factor X (Xa), Ca +, and phospholipids transform prothrombin to thrombin, which initiates the synthesis of fibrinogen to fibrin, amplifies the activation of Factors V, Vin, XI, and XII and furthermore triggers platelet activation and aggregation. Finally, fibrin strengthens the clot of the activated and adhered platelets. 

---

Regulating blood cell adhesion via surface modification of polyurethanes... 

---