In westernized societies, atherosclerosis and its clinical consequences such as heart disease and stroke constitute the leading cause of death, accounting for around 16.7 million deaths/year. Current knowledge recognizes a whole range of indicators associated with atherosclerosis, including concentrations of various lipoprotein particles (low density lipoprotein (LDL), oxidized LDL (oxLDL), high density lipoprotein (HDL), and the lipoprotein-like particle lp(a) or apolipoproteins among others). To date, we still do not know the impact that the apolipoprotein isoform, the apolipoprotein oxidation state, the lipid cargo and the presence of divalent ions have on the structure and stability of the lipoprotein particles, and therefore on the subsequent effects on interactions with blood vessel components. Neutron reflection can provide major insights into the exchange process occurring at mimics of biological interfaces. This project will thus provide unique information into the molecular mechanisms behind the importance of biological markers such as LDL, HDL total concentrations as well as the LDL/HDL ratio, advancing novel strategies in the fight against atherosclerosis.