"While nanotechnology-based products and nanoparticle mediated solution for a wide range of applications are constantly surface the market, there is increased interest and concern, around the benefits and risks of this technology. As nanoparticles size crosses the barrier of 100 nm, many of the traditional laws break down and other effects and properties start dominating (quantum size effects, extremely high surface energy etc). This raises questions regarding the suitability of traditional methods, such as in-vitro test kits and in-vivo animal models used to evaluate their potential toxicity. It is therefore essential to understand the cell - nanoparticle interaction at a fundamental molecular level in complex or simplified biological environments in order to asses their potential toxicity. Further on this foundation the modulation of the nanoparticle properties will allow for optimal performance in drug delivery, bioimaging, medical device coatings, bio-sensors, biochip development, biofouling protection and mitigate nanotoxicology.The major aim of this research endeavor is to study and understand the interactions that take place at the nano-bio interface, as a function of the particle size and the proteins from the biological environment that have been adsorbed on the surface of the particle. To achieve that we propose the utilization of two state of the art surface sensitive techniques; ie the Atomic Force Microscope and the Acoustic Biosensors, that will be used either separately or in combination for the study of the the interaction force and the structural changes that occur. Initially these interactions will be studied on a simplified membrane model, to avoid complex interactions, a supported lipid bilayer, in order to understand the foundation of these interactions, and later transition to an in-vitro model, an actual cell, to study the interaction in a natural, more realistic environment."