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Cardiovascular medical devices are used to treat a number of life-threatening diseases. However, the intervention can have severe complications, such as thrombosis and stent migration, which can be linked to mechanical interaction between blood vessel and medical device. Being located at the surface of blood vessels, the endothelial cells are both at the interface of the frictional interaction and responsible for suppressing factors leading to some of the complications. Therefore, a damaged endothelium can have severe implications. The interaction between medical devices and blood vessels has still not been understood to a satisfactory degree. This work aimed to study the influence of load (normal force) and material choice on friction, to quantify damage to the monolayer, and lays a foundation for meaningful experiments to find more suitable materials causing less, or less severe, complications in the future. The tribological methodology developed in the context of this work overcomes issues with previous studies and constitutes a way of testing how much friction and damage different probe materials generate under more physiologically-relevant conditions by deploying a soft substrate populated with an endothelial monolayer. A way has been developed to account for a well-known issue in low-friction experiments due to misalignments in the set-up. Furthermore, a new way of quantifying the extent of the induced damage in terms of live, dead and removed cells has been deployed. A key feature of the methodology is that it works without expensive microtribometers and achieves extremely low pressures in the two digit kPa range with a standard tribometer (UMT2 by Bruker), making it adaptable by other research institutions without much cost. This set-up could be used, however, to achieve higher pressures too, either by choosing a harder substrate, or by simply increasing the normal load. The results quantify the damage induced by three different probe materials (glass, stent-grade stainless steel and PTFE) due to friction and indentation and show differences between the materials. These data are analysed and discussed in depth to explain the apparent mechanisms at a cell level. As a conclusion, friction was successfully measured and damage assessed on endothelial cell monolayers which can be employed without great costs and quickly yield results that could have significant implications. Even after only testing glass, stainless steel and PTFE in this work, it became clear that there are materials in some medical devices - which are in contact with the endothelium - that induce severe damage. As such, techniques and tools developed in the context of this work could be used to test existing materials and to develop new ones that could reduce the risk of complications for many people.