Research

Shape and orientation matter for cellular uptake of non-spherical nanoparticles

Nano Lett., 2014, 14 (2), pp 687–693 DOI: 10.1021/nl403949h

Sabyasachi Dasgupta , Thorsten Auth , and Gerhard Gompper
Recent advances in nano-technology have made a whole zoo of particles of different shapes available for applications, but their interaction with biological cells and their toxicity is often not well understood. Experiments have shown that particle uptake by cells […]

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Lipid oxidation induces structural changes in biomimetic membranes

Soft Matter, 10, 4241-4247 (2014)
G. Weber, T. Charitat, M. S. Baptista, A. F. Uchoa, C. Pavani, H. C. Junqueira, Y. Guo, V. A. Baulin, R. Itri, C. M. Marques, A. P. Schroder

Oxidation can intimately influence and structurally compromise the levels of biological self-assembly embodied by intracellular and plasma membranes. Lipid peroxidation, a natural metabolic outcome of […]

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Phase coexistence and mechanical properties of biological membranes

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Nanoparticle functionalization and assembly and nano particle interface interactions

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Computer simulations of protein-bilayer interactions

Mutual adaptation of the structure in molecular motors and impact of structural changes in the thermodynamic efficiency of the molecular motor.

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Interaction of peptides and proteins with membranes

Cell membranes represent a serious protective barrier for external molecules, proteins, nanoparticles and drugs. This barrier is quite efficient in protecting the interior of the cells. Cell penetrating peptides, certain proteins, pore forming peptides can preferentially interact with lipid membranes and form different structures. Very little can be said about the pathway and the entry […]

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Dual modes of antitumor action of an amphiphilic peptide A9K

Hai Xu, Cui Xia Chen, Jing Hua, Peng Zhou, Ping Zeng, Chang Hai Cao, Jian Ren Lu
Biomaterials, 34, 2731-2737 (2013)
Following our recent report of attractive antibacterial properties of a designed amphiphilic peptide, A9K, we have investigated its antitumor activities by examining the modes of its action against different mammalian cell types. The peptide strongly inhibited […]

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Wrapping of ellipsoidal nano-particles by fluid membranes

Sabyasachi Dasgupta, Thorsten Autha, Gerhard Gompper

Soft Matter, 9, 5473-5482 (2013)

Membrane budding and wrapping of particles, such as viruses and nano-particles, play a key role in intracellular transport and have been studied for a variety of biological and soft matter systems. We study nano-particle wrapping by numerical minimization of bending, surface tension, and adhesion energies. We […]

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Mechanisms of Vesicle Spreading on Surfaces: Coarse-Grained Simulations

Marc Fuhrmans, Marcus Müller

Langmuir, 29 (13), pp 4335–4349 (2013)

Exposition of unilamellar vesicles to attractive surfaces is a frequently used way to create supported lipid bilayers. Although this approach is known to produce continuous supported bilayer coatings, the mechanism of their formation and its dependence on factors like surface interaction and roughness or membrane tension as […]

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Poly-ethylene glycol induced super-diffusivity in lipid bilayer membranes

Thibault Tabarin, Aaron Martin, Robert J. Forster and Tia E. Keyes

Soft Matter, 8, 8743-8751 (2012)

Fluorescence lifetime correlation spectroscopy (FLCS) has been used to probe the influence of PEG-8000 on the fluidity of fluorescently labeled planar supported lipid bilayers on ozone plasma treated glass. The lipid membrane compositions examined were; DOPC, DOPC/DOPS (80/20 mol/mol) […]

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Line-Tension Controlled Mechanism for Influenza Fusion

Herre Jelger Risselada, Giovanni Marelli, Marc Fuhrmans, Yuliya G. Smirnova, Helmut Grubmüller, Siewert Jan Marrink, Marcus Müller

PLoS ONE 7(6): e38302 (2012)

Our molecular simulations reveal that wild-type influenza fusion peptides are able to stabilize a highly fusogenic pre-fusion structure, i.e. a peptide bundle formed by four or more trans-membrane arranged fusion peptides. We rationalize that the […]

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Homo-polymers with balanced hydrophobicity translocate through lipid bilayers and enhance local solvent permeability

Marco Werner, Jens-Uwe Sommer and Vladimir A. Baulin

Soft Matter, 8, 11708-11716 (2012)

Recent experimental studies indicate that polymeric structures with a well-adjusted balance of amphiphilic parts may translocate through self-assembled phospholipid bilayers and enhance the passive trans-membrane transport of smaller molecules. Using a coarse grained lattice Monte Carlo model with explicit solvent we investigate self-assembled lipid […]

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Manipulation and sorting of membrane proteins using patterned diffusion-aided ratchets with AC fields in supported lipid bilayers

Matthew R. Cheetham, Jonathan P. Bramble, Duncan G. G. McMillan, Richard J. Bushby, Peter D. Olmsted, Lars J. C. Jeuken and Stephen D. Evans

Soft Matter, 2012,8, 5459-5465

We present ratchets capable of directing the movement of charged components within supported bilayer lipid membranes. These ratchets make use of asymmetrically patterned features […]

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Permeability of lipid bilayers induced by polymers

Lipid bilayers emerge by self-organization of amphiphilic molecules and are the essential component of membranes of living cells. An important task of them is the selective exchange of substances between the cell and its environment. This becomes particularly interesting for delivering foreign molecules and RNA into the cell. In the classical view of cell biology […]

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Critical adsorption controls translocation of polymer chain through lipid bilayers and permeation of solvent

J.-U. Sommer, M. Werner and V. A. Baulin

Europhysics Letters, 98, 18003 (2012)

Monte Carlo simulations using an explicit solvent model indicate a new pathway for translocation of a polymer chain through a lipid bilayer. We consider a polymer chain composed of repeat units with a given hydrophobicity and a coarse-grained model of a lipid bilayer in […]

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Biomolecule Surface Patterning May Enhance Membrane Association

S. Pogodin, N. K. H. Slater and V. A. Baulin

ACS Nano, 6(2), 1308-1313 (2012)

Under dehydration conditions, amphipathic late embryogenesis abundant proteins fold spontaneously from a random conformation into α-helical structures, and this transition is promoted by the presence of membranes. To gain insight into the thermodynamics of membrane association, we model the resulting α-helical structures […]

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Translocation of nanoparticles, carbon nanotubes and polymers through bilayers

Cell membranes represent a serious protective barrier for external molecules, proteins, nanoparticles and drugs. This barrier is quite efficient in protecting the interior of the cells. However, large nanoscale objects, single-walled carbon nanotubes (SWNTs) have been found inside the cells both in direct and indirect biological experiments. Such experiments suggest that carbon nanotubes can efficiently […]

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Coupled concentration polarization and electroosmotic circulation near micro/nanointerfaces: Taylor–Aris model of hydrodynamic dispersion and limits of its applicability

A. Yaroshchuk, E. Zholkovskiy, S. Pogodin and V.A. Baulin
Langmuir, 27(18), 11710-11721 (2011)

Mismatches in electrokinetic properties between micro- and nanochannels give rise to superposition of electroosmotic and pressure-driven flows in the microchannels. Parabolic or similar flow profiles are known to cause the so-called hydrodynamic dispersion, which under certain conditions can be formally assimilated to an […]

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Equilibrium insertion of nanoscale objects into phospholipid bilayers

S. Pogodin and V.A. Baulin
Current Nanoscience, 7 (5), 721-726 (2011)

Certain membrane proteins, peptides, nanoparticles and nanotubes have rigid structure and fixed shape. They are often viewed as spheres and cylinders with certain surface properties. Single Chain Mean Field theory is used to model the equilibrium insertion of nanoscale spheres and rods into the phospholipid bilayer. […]

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Surface patterning of carbon nanotubes can enhance their penetration through a phospholipid bilayer

S. Pogodin, N.K.H. Slater and V.A. Baulin
ACS Nano, 5 (2), 1141–1146 (2011)

Nanotube patterning may occur naturally upon the spontaneous self-assembly of biomolecules onto the surface of single-walled carbon nanotubes (SWNTs). It results in periodically alternating bands of surface properties, ranging from relatively hydrophilic to hydrophobic, along the axis of the nanotube. Single-chain mean field (SCMF) […]

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Coarse-grained models of phospholipid membranes within the single chain mean field theory

S. Pogodin and V.A. Baulin
Soft Matter, 6, 2216 – 2226 (2010)
The single chain mean field theory is used to simulate the equilibrium structure of phospholipid membranes at the molecular level. Three levels of coarse-graining of DMPC phospholipid surfactants are present: the detailed 44-beads double tails model, the 10-beads double tails model and the minimal 3-beads […]

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Can a carbon nanotube pierce through a phospholipid bilayer?

S. Pogodin and V.A. Baulin
ACS Nano, 4 (9), 5293–5300 (2010)
Great efficiency to penetrate into living cells is attributed to carbon nanotubes due to a number of direct and indirect observations of carbon nanotubes inside the cells. However, a direct evidence of physical translocation of nanotubes through phospholipid bilayers and the exact microscopic mechanism of their […]

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