In this project, biomimetic surfaces functionalized with heparin are developed and characterized and their therapeutic application potential is investigated. These surfaces are called "biomimetic" because heparin is an analogue of heparan sulphate, a strongly negatively charged substance which, as a "glycocalyx", covers various cells of the human organism, especially the surface of the endothelium (inner surface of blood vessels; interface between tissue and blood). This glycocalyx has anticoagulant properties and prevents cells from attaching to the endothelial surface under physiological conditions. In the context of chronic or acute inflammation, the glycocalyx is shed, and the endothelium is damaged and loses its anticoagulant properties and its barrier function between blood and tissue. The surfaces developed and characterized in this project can be used both to investigate and elucidate the mechanisms of systemic inflammatory reactions (sepsis, COVID-19) and for therapeutic purposes in the context of extracorporeal blood purification procedures.