Posts by Yachong Guo published at ITN SNAL - Marie Curie Initial Training Network

Bactericidal activity of self-assembled palmitic and stearic fatty acid crystals on highly ordered pyrolytic graphite

Yachong Guo — Mon, 04 Sep 2017 14:01:32 +0000

Acta Biomaterialia, 59, 148-157 (2017). Elena P. Ivanova, Song Ha Nguyen, Yachong Guo, Vladimir A. Baulin, Hayden K. Webb, Vi Khanh Truong, Jason V. Wandiyanto, Christopher J. Garvey, Peter J. Mahon, David E. Mainwaring, Russell J. Crawford The wings of insects such as cicadas and dragonflies have been found to exhibit nanostructure arrays that are assembled from fatty acids, and that physically interact with and significantly disrupt bacterial cell membranes. Such mechanobactericidal surfaces are of significant interest, as they can kill bacteria without the need for antibacterial chemicals. Here, we report on the bactericidal effect of two main lipid components of

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Apatite nanoparticles strongly improve red blood cell cryopreservation by mediating trehalose delivery via enhanced membrane permeation

Yachong Guo — Mon, 26 Jun 2017 11:51:52 +0000

Biomaterials, 140, 138-149 (2017). Martin Stefanic, Kevin Ward, Harvey Tawfik, Ralf Seemann, Vladimir Baulin, Yachong Guo, Jean-Baptiste Fleury, Christophe Drouet Cryopreservation of red blood cells (RBC) is an important method for maintaining an inventory of rare RBC units and managing special transfusion circumstances. Currently, in a clinical setting, glycerol is used as cryoprotectant against freezing damage. After thawing and before transfusion, glycerol must however be removed to avoid intravascular hemolysis, via a complex and time-consuming deglycerolization process which requires specialized equipment. Improved cryopreservation methods using non-toxic agents are required to increase biocompatibility and decrease processing time. Biocompatible cryoprotectants (e.g. trehalose)

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Peroxidised phospholipid bilayers: insight from Coarse-Grained Molecular Dynamics simulations

Yachong Guo — Wed, 06 Jan 2016 08:46:42 +0000

Soft Matter, 12, 263-271 (2016) Yachong Guo, Vladimir Baulin and Fabrice Thalmann An original coarse-grained model for peroxidised phospholipids is presented, based on the MARTINI lipid force field. This model results from a combination of thermodynamic modelling and structural information on the area per lipid, which have been made available recently. The resulting coarse-grained lipid molecules form stable bilayers, and a set of elastic coefficients (compressibility and bending moduli) is obtained. We compare the compressibility coefficient to the experimental values . Predictions for mechanical properties, membrane thickness and lateral distribution of hydroperoxide groups in the

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Graphene Induces Formation of Pores That Kill Spherical and Rod-Shaped Bacteria

Yachong Guo — Mon, 07 Sep 2015 11:35:57 +0000

ACS Nano, DOI: 10.1021/acsnano.5b03368 (2015) Vy T. H. Pham, Vi Khanh Truong, Matthew D. J. Quinn, Shannon M. Notley, Yachong Guo, Vladimir A. Baulin, Mohammad Al Kobaisi, Russell J. Crawford, and Elena P. Ivanova Pristine graphene, its derivatives, and composites have been widely reported to possess antibacterial properties. Most of the studies simulating the interaction between bacterial cell membranes and the surface of graphene have proposed that the graphene-induced bacterial cell death is caused either by (1) the insertion of blade-like graphene-based nanosheets or (2) the destructive extraction of lipid molecules by the presence of the lipophilic graphene. These simulation studies

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SCMF – Single Chain Mean Field Theory

Yachong Guo — Sun, 26 Oct 2014 22:08:00 +0000

Basics The Single Chain Mean Field (SCMF) theory was originally proposed by Ben-Shaul, Szleifer and Gelbart to describe micellization of block copolymers. This method has further been developed to describe the structure of phospholipid membranes at the molecular level. SCMF is one of the theoretical tools exploited in the Molecular Simulation group in Tarragona. The SCMF theory describes a single molecule surrounded by the mean fields. It takes explicitly into account the structure of an individual molecule at a coarse-grained level similar to coarse-grained MC or MD simulations. However, as distinct from simulations, the interactions of the molecule with the environment are described

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Association of polymers and small solute molecules with phospholipid membranes

Yachong Guo — Mon, 13 Oct 2014 12:48:32 +0000

Theoretical physics, theory in soft matter, computer simulations Objectives In many cases the properties of cell membranes are modified through biopolymers and small solute molecules such as anesthetics or neurotransmitters. They can associate to membranes and significantly alter their structure, either thermodynamic state or induce reorganization in form of pores. The project aims to describe the fundamental controls of these processes that trigger such membrane modification or structural reorganization using the Single Chain Mean Field (SCMF) theory. Tasks and methodology Implementation of a hybrid Single Chain Mean Field theory with Monte Carlo simulations Construction of the models for polymer – bilayer

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General model of phospholipid bilayers in fluid phase within the single chain mean field theory

Yachong Guo — Wed, 07 May 2014 21:57:24 +0000

J. Chem. Phys. 140, 174903 (2014) Yachong Guo, Sergey Pogodin and Vladimir A. Baulin Coarse-grained model for saturated phospholipids: 1,2-didecanoyl-sn-glycero-3-phosphocholine (DCPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and unsaturated phospholipids: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2- dioleoyl-sn-glycero-3-phosphocholine (DOPC) is introduced within the single chain mean field theory. A single set of parameters adjusted for DMPC bilayers gives an adequate description of equilibrium and mechanical properties of a range of saturated lipid molecules that differ only in length of their hydrophobic tails and unsaturated (POPC, DOPC) phospholipids which have double bonds in the tails. A double bond is modeled with a fixed angle of

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Nanotopography as a trigger for the microscale, autogenous and passive lysis of erythrocytes

Yachong Guo — Thu, 20 Mar 2014 17:39:48 +0000

J. Mater. Chem. B, 2 (19), 2785-2948 (2014) Vy T. H. Pham, Vi Khanh Truong, David E. Mainwaring, Yachong Guo, Vladimir Baulin, Mohammad Al Kobaisi, Gediminas Gervinskas, Saulius Juodkazis, Wendy R. Zeng, Pauline Doran, Russell J Crawford and Elena P. Ivanova Microscale devices are increasingly being developed for diagnostic analysis although conventional lysis as an initial step presents limitations due to scale or complexity. Here, we detail the physical response of erythrocytes to surface nanoarchitecture of black Si (bSi) and foreshadow its potential in microanalysis. The physical interaction brought about by the spatial convergence of the two topologies: (a) the nanopillar

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Lipid oxidation induces structural changes in biomimetic membranes

Yachong Guo — Wed, 01 Jan 2014 12:21:40 +0000

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 life with oxygen under light, is also a salient oxidation reaction in photomedecine treatments. However, the effect of peroxidation on the fate of lipid membranes remains elusive. Here we use a new photosensitizer that anchors and disperses in the membrane to achieve spatial

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