Surface Structures


Johanna Clauser


Johanna Clauser

Group Leader Hemocompatibility & Blood Experiments


+49 241 80 89356




When a foreign material gets into contact with the human blood a foreign body reaction is initiated which leads amongst others to the activation of the platelets. In the course of the coagulation cascade these activated platelets adhere onto the material’s surface which can for example lead to the failure of the medical device or thromboembolism. In order to reduce the risk of thrombosis of such devices there is the need for improving the hemocompatibility. Therefore, several attempts on surface modification were made including inorganic coatings of the surfaces, structural changes or variations of the chemical properties. As a result, micro structuring turned out to be a successful method for improving the hemocompatibility of medical devices because this method does not affect the original properties of the used material.

  Lasercanning microscopy image of microstructured PCU samples AME Figure 1: Lasercanning microscopy image of microstructured PCU samples


Previous investigations showed that micro structuring of polymer biomaterials is a suitable method for reducing platelet activation and adhesion and thus contributes to an improved hemocompatibility. Up to now, the relationship between such a structure and its impact on the hemocompatibility cannot be explained in detail because the particular correlations are still unknown. Therefore, the aim of this study is to investigate the interaction between surface structures and platelets considering different structure geometries (see Figure 1) and flow conditions on Polycarbonate-Urethane surfaces (PCU). This is the first step towards future applications of microstructured surfaces in the course of medical product development and hemocompatibility improvement.

  In-vitro blood experiment in flow chambers AME Figure 2: In-vitro blood experiment in flow chambers


In order to observe the platelets‘ reaction on microstructured surfaces dynamic in-vitro studies with porcine blood will be carried out (Figure 2). Different flow conditions will be applied to investigate their influence on the structure-platelet interaction. The analysis of activated and adherent platelets on the surfaces is done by means of coagulation parameters and optical fluorescence microscopy (Figure 3).

  Fluorescence microscopy of activated platelets AME Figure 3: Fluorescence microscopy of activated platelets  
Funding: This research project is supported by the START-Program of the Faculty of Medicine, RWTH Aachen