Translocation and Induced Permeability of Random Amphiphilic Copolymers Interacting with Lipid Bilayer Membranes

Werner, Marco; Sommer, Jens‐Uwe

doi:10.1021/bm501266x

Cited by 42 publications

(66 citation statements)

References 55 publications

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“…Here, Z is an average coordination number taken from the simulations (Z ≈ 4−7, depending on H B ), ϵ 0 = 0.8k B T the energy scale as before, and μ ins ≈ 0.9k B T 27,29,33. …”

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confidence: 99%

Interactions of Amphiphilic Triblock Copolymers with Lipid Membranes: Modes of Interaction and Effect on Permeability Examined by Generic Monte Carlo Simulations

2015

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We investigate interactions of linear amphiphilic ABA triblock copolymers with lipid bilayer membranes by means of Monte Carlo simulations in a generic coarse-grained model. The polymers have hydrophilic A-blocks and B-blocks of varying hydrophobicity. The effect of different conformational states of the polymer on the induced permeability for solvent molecules is examined. We demonstrate that the local permeability of the membrane can be strongly increased in the transmembrane state, in particular for a mismatch in the hydrophobicity between the middle block and the membrane core, while the hairpin state has almost no effect on this property, especially for growing hydrophobic mismatch. We have investigated the relative stability of the two states using thermodynamic integration and have shown that only in a range of intermediate hydrophobic block lengths N B and hydrophobicities H B the transmembrane state is stable. Increasing mismatch of the B-block in terms of relative hydrophobicity and block length not only causes stronger perturbations in the membrane if the polymer is in the transmembane state but also renders this state metastable. Our studies support in particular previous experimental studies suggesting a two-state model of PEO−PPO−PEO copolymers.

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“…Here, Z is an average coordination number taken from the simulations (Z ≈ 4−7, depending on H B ), ϵ 0 = 0.8k B T the energy scale as before, and μ ins ≈ 0.9k B T 27,29,33. …”

mentioning

confidence: 99%

Interactions of Amphiphilic Triblock Copolymers with Lipid Membranes: Modes of Interaction and Effect on Permeability Examined by Generic Monte Carlo Simulations

2015

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“…Previous simulation studies on linear homopolymers 45,46 and amphiphilic copolymers 56 showed that a polymer suppresses permeability when fully embedded in the bilayer's core in the limit large hydrophobicity. Experimental data on PP50, however, indicate that full insertion of amphiphilic branched polymer is not necessary for suppression of permeability, if anchoring side groups are sufficiently hydrophobic.…”

Section: Coarse Grained Monte Carlo Simulationmentioning

confidence: 99%

“…By decreasing the value of H to H = 0.8, the hydrophobicity of the side chains gets close to a point of balanced hydrophobicity, where a polymer-induced increase of permeability has been seen for homopolymers 45,46 as well as random amphiphilic copolymers. 56…”

Section: Coarse Grained Monte Carlo Simulationmentioning

confidence: 99%

Dynamic studies of the interaction of a pH responsive, amphiphilic polymer with a DOPC lipid membrane

et al. 2017

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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 = pK = 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.

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“…As the interior region of the phospholipid bilayer membrane is hydrophobic, hydrophilic molecules do not readily cross cell membranes [24][25][26]. Due to this property, an electron mediator must have sufficient hydrophobicity to permeate cell membranes [15,27].…”

Section: 1 Characterization Of Pmfcsmentioning

confidence: 99%

Molecular design of cytocompatible amphiphilic redox-active polymers for efficient extracellular electron transfer

Kaneko

Ishikawa

Hashimoto

et al. 2017

Bioelectrochemistry

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For electrochemical regulations of the intracellular metabolisms, lipophilic electron mediators with cell membrane permeability have been conventionally used. We have recently developed amphiphilic, cell-membrane permeable polymer composed of hydrophilic 2-methacryloyloxyethyl phosphorylcholine and hydrophobic redox-active units as a new category of electron mediator. The advantage of the redox active polymer is that we can obtain appropriate molecules in a synthetic bottom-up manner. Here we report that the rate of the extracellular electron transfer (EET) through the redox active polymer can be regulated by sophisticated molecular design of the polymers. It was also shown that the cellular metabolism of yeast Saccharomyces cerevisiae was regulated by using the polymer with the highest EET rate.

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Translocation and Induced Permeability of Random Amphiphilic Copolymers Interacting with Lipid Bilayer Membranes

Cited by 42 publications

References 55 publications

Interactions of Amphiphilic Triblock Copolymers with Lipid Membranes: Modes of Interaction and Effect on Permeability Examined by Generic Monte Carlo Simulations

Interactions of Amphiphilic Triblock Copolymers with Lipid Membranes: Modes of Interaction and Effect on Permeability Examined by Generic Monte Carlo Simulations

Dynamic studies of the interaction of a pH responsive, amphiphilic polymer with a DOPC lipid membrane

Molecular design of cytocompatible amphiphilic redox-active polymers for efficient extracellular electron transfer

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