The rapid development of nanomaterials has led to an increase in the number and variety of engineered nanomaterials (ENMs) in the environment. We are continuously exposed to products containing ENMs such as batteries, catalysts, chemical coatings, biomedicines and cosmetics. The expanding production of ENMs has led to serious concerns regarding their impact on human health and the environment (for example the considerable investment made by the EU in nanosafety research in the H2020 programme). Given this degree of exposure, it is striking that implications for environmental and human health remain mostly unknown or poorly understood. Identifying ENMs hazardous to natural organisms is difficult, given the wide variety of NPs, their diverse properties (e.g. particle material, size, shape, surface, charge, corona) and the complexity of biological entities (e.g. membrane and media composition, type of cell, cell cycle). The interaction of inorganic NPs with biological systems can lead to severe cytotoxic effects. Although there is a vast literature that highlight the biological impact of the NP exposure, a detailed physicochemical description of nanoparticle and cell interactions and adverse outcomes relevant to predict in vivo behaviour does not exist. In fact, most of the published studies offer no conclusive nanotoxicological data for in vitro models which might make it possible to predict an in vivo response. In order to be able to distinguish between harmless and harmful nanomaterials significant progress must be made in understanding the relevant interactions or key initiating events at nano bio interfaces and determining the NM properties relevant for these interactions.
One route to being able to predict nanotoxicological responses is through in silico approaches that, based on a detailed understanding of toxicity pathways and nano biomolecular structure and dynamics, correlate materials descriptors (physical properties such as size, shape, electronic energy levels, lipid adsorption energies) with toxicological outcomes. Such a model is only possible if there exist reliable physical property data either from experiment and nanoscale simulation. Since one of the first steps in a toxicological response will be the nanoparticle meeting the cell membrane, it is clear that, prominent amongst the materials descriptors, will be the nanomaterial and lipid interaction characterised by its heat of adsorption. In this work, we will present the first experimental quantification data and thermodynamic properties of NP and lipid interaction obtained via calorimetry, coupled with TEM and DLS physical chemical analysis. Studies that could be used for the construction of an in silico model able to predict potential membrane perturbations and consequently, cytotoxic effects. For the experiments, NPs made with different inorganic materials, surface charge and size have been used, while the lipid considered were both in free and assembled (liposome) state.