Cell-nanoparticle interactions are complex, involving several specific and non-specific intermolecular forces between a wide range of particulate and molecular species . There is growing evidence that the cellular uptake mechanism of a range of inorganic nanoparticles is highly variable, with uptake via endocytosis or a more direct penetration occurring for different nanoparticles with, for example, different surface charges , or small differences in ligand structure . A key factor in any uptake mechanism is how the cell membrane structure changes in response to nanoparticle adsorption, and the degree of binding of the particles to the cell surface prior to mooted uptake. In this proposal we seek to complement our studies of cell-nanoparticle interactions and XRR results, by varying measuring the effect of NP adsorption on monolayer integrity and structure, using contrast variation