Berlin 2018 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
BP: Fachverband Biologische Physik
BP 22: Computational Biophysics II
BP 22.1: Talk
Wednesday, March 14, 2018, 15:00–15:15, H 1058
anionic and cationic gold nanoparticles in model lipid membranes: experiments and simulations — ester canepa2, •sebastian salassi1, federica simonelli1, riccardo ferrando2, ranieri rolandi1, chiara lambruschini2, annalisa relini2, and giulia rossi1 — 1Physics department — 2Chemistry department, University of Genoa, Genoa, Italy
Designing metal nanoparticles (NPs) with biomedical applications requires the molecular understanding of their interaction with cell membranes. We use fluorescence spectroscopy measurements and molecular dynamics (MD) simulations to study the interaction between charged monolayer-protected AuNPs and model POPC lipid bilayer[1-2]. We consider cationic (NP+) and anionic (NP-) NPs. The anionic ligands differ from the cationic ones for their terminal group, which is a carboxylate or a quaternary ammonium ion. We use fluorescence leakage assays to quantify the damage induced by NP- and NP+ to liposomes, and find that NP+ are more disruptive. MD simulations offer a molecular interpretation of this result. Assuming no changes of the charge of NP+ and NP- they interact with the bilayer with the same mechanism[3] and bilayer deformation. Our simulations, though, show that anionic ligands can be protonated when interacting with the lipid head. Once protonated, the NP- interact with the bilayer in a less disruptive way, without deforming or damaging it. This change of the pKa of the anionic ligands can explain the smaller leakage induced by NP-.
1.Tatur, S et all. Langmuir 2013. 2. Van Lehn,R. C. et all. Nano Lett. 2013. 3. Salassi, S. et all. JPCC 2017.