Author, as appears in the article.: Ramadurai S, Werner M, Slater NKH, Martin A, Baulin VA, Keyes TE.
Department: Enginyeria Química
e-ISSN: 1744-6848
URV's Author/s: Baulin, Vladimir
Keywords: Poly(l-lysine iso-phthalamide) Peptides Model membranes Lifetime correlation spectroscopy Lateral diffusion Hydrophobic mismatch Fluorescence correlation spectroscopy Cell-membrane Blood-cells Bilayer-membranes
Abstract: Deeper understanding of the molecular interactions between polymeric materials and the lipid membrane is important across a range of applications from permeation for drug delivery to encapsulation for immuno-evasion. Using highly fluidic microcavity supported lipid bilayers, we studied the interactions between amphiphilic polymer PP50 and a DOPC lipid bilayer. As the PP50 polymer is pH responsive the studies were carried out at pH 6.5, 7.05 and 7.5, corresponding to fully, partly protonated (pH = pKa = 7.05) and fully ionized states of the polymer, respectively. Fluorescence correlation spectroscopy (FCS) using both labelled lipid and polymer revealed the PP50 associates with the bilayer interface across all pHs where its diffusion along the interface is impeded. Both FCS and electrochemical impedance spectroscopy (EIS) data indicate that the PP50 does not penetrate fully into the bilayer core but rather forms a layer at the bilayer aqueous interface reflected in increased resistance and decreased capacitance of the bilayer on PP50 binding. The extent of these effects and the dynamics of binding are influenced by pH, increasing with decreasing pH. These experimental trends concurred with coarse grained Monte Carlo simulations of polymer-bilayer interactions wherein a model hydrophilic polymer backbone grafted with side chains of varying hydrophobicity, to mimic the effect of varying pH, was simulated based on the bond fluctuation model with explicit solvent. Simulation results showed that with increasing hydrophobicity, the polymer penetrated deeper into the contacting bilayer leaflet of the membrane suppressing, consistent with EIS data, solvent permeation and that a full insertion of the polymer into the bilayer core is not necessary for suppression of permeability.
Thematic Areas: Química Polymer science Physics, multidisciplinary Materials science, multidisciplinary Materiais Interdisciplinar General chemistry Farmacia Engenharias iv Engenharias iii Engenharias ii Condensed matter physics Ciências biológicas ii Ciências biológicas i Ciências agrárias i Chemistry, physical Chemistry (miscellaneous) Chemistry (all) Biotecnología Astronomia / física
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 1744-683X
Author's mail: vladimir.baulin@urv.cat
Author identifier: 0000-0003-2086-4271
Record's date: 2024-09-07
Papper version: info:eu-repo/semantics/publishedVersion
Link to the original source: https://pubs.rsc.org/en/content/articlelanding/2017/sm/c6sm02645a#!divAbstract
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: Soft Matter. 13 (20): 3690-3700
APA: Ramadurai S, Werner M, Slater NKH, Martin A, Baulin VA, Keyes TE. (2017). Dynamic studies of the interaction of a pH responsive, amphiphilic polymer with a DOPC lipid membrane. Soft Matter, 13(20), 3690-3700. DOI: 10.1039/C6SM02645A
Article's DOI: 10.1039/c6sm02645a
Entity: Universitat Rovira i Virgili
Journal publication year: 2017
Publication Type: Journal Publications