CD41 Western blotting: a new method to detect platelet adhesion to artificial surfaces used in extracorporeal circulation procedures.

Cardiopulmonary bypass (CPB) surgery is associated with platelet activation and reduced platelet counts due to artificial surface activation of blood elements and non-physiological flow-patterns. As shown in former studies, coating of medical devices can improve hemocompatibility in extracorporeal circulation systems. In this study, we demonstrate a new method to determine platelet adhesion on 18 coated and non-coated membrane oxygenators in a simulated CPB model with CD41 Western blot. Platelet loss and the release of beta-TG (platelet activation marker) were determined during a 120 min recirculation phase. At the end of the run the membrane oxygenators (with tubing system) were rinsed and the amount of adsorbed proteins on the surface was analyzed by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting technique. Uncoated devices showed significantly higher concentrations of CD41 and of fibrinogen adsorption compared to the coated membrane oxygenators. These results correspond with the release of beta-TG and platelet loss indicating less platelet adhesion on the coated oxygenators compared with the uncoated group. This new method may be useful in choosing less platelet activating materials for all kind of blood contacting devices to improve thrombogenicity including platelet functionality.