Poloxamers and their interaction with lipid bilayers

J.M.R. ALBANO; I. WOOD; M. PICKHOLZ

RECIFE

Workshop; ASBioSIM; 2015

ASBioSIM

Poloxamers, also known as Pluronics, are non-ionic triblock co-polymers composed of a central hydrophobic poly(propyleneoxide) (PPO) chain capped by two hydrophilic chains of poly(ethylene oxide) (PEO). These amphiphilic co-polymers can interact strongly with the cell membranes and modify its mechanical properties [1]. In this work, we aim to investigate the interaction of the poloxamer L81 with POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine) phospholipid bilayers through Molecular Dynamics (MD) simulations at a Coarse Grain (CG) level. Firstly, in order to refine a parametrization of pluronic within a CHARMM forcefield, we carried out quantum chemical calculations of the polymers of PPO and PEO as function of the monomer numbers, as well as for short co-polymers. Lipid bilayers were build up using the packmol program [2] and the poloxamer was added in 3 different environments, water, interphase and bilayer core. MD-CG simulations were carried out and preliminar results show the affinity of the poloxamer for the interphase, with the PPO blocks anchored in the bilayer and the PEO tails solvated in water.Acknowledgements: ANPCyT, UBA, CONICET. References 1- Nawaz, S. et al. Soft Matter. 2012. 6744 2- Martínez, L. et al. J. Comput. Chem. 2009. 2157