Interactions between synthetic nanomaterials and model biological membranes

Nanomaterials are more and more often synthesized for high-tech applications ranging from innovative material design to nanomedicine. On the other hand, undesired nanomaterials can be released in the environment. Independently of the mechanism of exposure, when nanomaterials interact with living organisms the first barrier they come in contact with is the cell membrane. In this talk we present a computational approach to the study of the molecular mechanisms that regulate the interaction of nanomaterials with cell membranes. We will consider both polymer nanoparticles and ligand-protected gold nanoparticles interacting with model lipid membranes of different compositions. Polymer nanoparticles can result from the degradation of common plastic materials and represent a hazard, especially for the marine wild life. We will show that polystyrene, polypropylene and polyethylene can severely perturb lipid membranes, especially in terms of mechanical properties and lateral heterogeneity [1,2,3]. Ligand-protected gold NPs, on the contrary, can be specifically designed to interact with cells, either for diagnostic or therapeutic, such as drug-delivery, applications. We will focus on the interaction between gold NPs, covered by a mixed shell of anionic and hydrophobic ligands, and zwitterionic lipid membranes, showing that the NP-membrane interaction is influenced by both the NP charge and the ligand surface arrangement [4].

[1] G. Rossi, J. Barnoud, and L. Monticelli, Polystyrene nanoparticles perturb lipid membranes, J. Phys. Chem. Lett. 2014, 5, 241−246
[2] G. Rossi and L. Monticelli, Modelling the effect of nano-sized polymer particles on the properties of lipid membranes, Topical Review, J. Phys.: Condens. Matter 2014, 26, 503101
[3] D. Bochicchio, E. Panizon, L. Monticelli and G. Rossi, The influence of three everyday-use hydrophobic polymers (polyethylene, polypropylene and polystyrene) on the properties of model lipid membranes, in preparation
[4] F. Simonelli, D. Bocchichio, R. Ferrando and G. Rossi, Monolayer-Protected Anionic Au Nanoparticles Walk into Lipid Membranes Step-by-Step, J. Phys. Chem. Lett., 2015, 6 (16), 3175-3179

Since 2013, Giulia Rossi has a Researcher position at the Physics Department of the University of Genoa. From 2011 to 2013, she worked at the Institut national de la santé et de la recherché médicale (INSERM) in Paris, with a Marie Curie IEF post-doc fellow. From 2008 to 2011, she was Post doc at the Department of Applied Physics at Aalto University School of Science in Helsinki. Giulia Rossi is a computational physicist, with a background in the physics of metals and alloys at the nanoscale. Nowadays her research interests span from metal nanoparticles, to polymers and biological membranes. In the last years she focused especially on the development of coarse-grained models of polymers and surfactants, to be applied to the study, at molecular level, of the interactions between synthetic nanomaterials and model biological membranes.