Polymers are commonly used in drug delivery to create dosage forms that enable delivery of the active ingredient to the site of action within the body. Towards controlled drug delivery polymers enable the development of systems that help to minimise side effects. There are a variety of ways in which polymers can interact with cell membranes, via specific receptors and also via disruption of the lipid membrane itself. We have been investigating the role of different properties of polymers on their ability to interact with lipid membranes. PAMAM is a highly branched polymer with either cationic (G5) or anionic (G4.5) end groups. In this proposal we ask for neutron reflectometry INTER beam time to investigate the interfacial structure of lipid layers in the presence of PAMAM G4.5 and G5.