With the dawn of nanosciences, the use of nanomaterials has become widespread in various scientific fields from cosmetics and electronics to medicines and their increasing use has led to the release of nanoparticles (NPs) in the environment. While NPs featuring gold cores (AuNPs) have been in use for decades for targeted drug delivery of cancer drugs, one important problem is that exposure to AuNPs from the environment is a potential health hazard. The lungs are easily exposed to these particles present in the atmosphere, making contact with the inner surface of the alveolus called the lung surfactant (LS). LS monolayer which consists of lipids, four types of proteins and other molecules, is the first barrier that these NPs encounters in order to enter the circulatory system. Despite exhaustive experimental studies, the molecular-level mechanism behind the translocation and permeation of environmental and engineered AuNPs into the LS is still poorly understood. Coarse-grained (CG) molecular dynamics (MD) will be carried out to study a model pulmonary surfactant (PS) film interacting with AuNPs of different sizes, shapes and concentration. Additionally, similar simulations will be carried out in presence of cholesterol and proteins SP-B and SP-C to investigate their effect on interactions with AuNPs at the air-water interface. A series of molecular-scale structural and dynamical properties of the surfactant film in the absence and presence of nanoparticle will be analysed, including phase behaviour, order parameter, pressure area isotherm, surface charge density, and area per lipid. Our preliminary results of CG system consisting DPPC: POPG lipids (7:3) and 3nm AuNPs show that AuNPs quickly interact with the lipid monolayer and create rupture in the monolayer. The nano-bio interactions impede the surface activity of the surfactant system during the normal breathing process and is in agreement with previously published experimental data by Bakshi et al. Our results will bring to the forefront the concern of the inhalation toxicity of AuNPs and their role in pulmonary disease. This PhD project will also provide guidelines for the future design of inhaled NPs with minimized side effects.