Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Shear-induced microstructures and dynamics processes of phospholipid cylinders in solutions.

ABSTRACT: Shear-induced microstructures and their corresponding dynamic processes are investigated for phospholipid cylinders in aqueous solution by dissipative particle dynamic simulation. Various phospholipid cylinders with cross-sections, which are formed under shear-free flow, are selected to examine the effects of shear flow on their structures and dynamic processes. Shear flow induces the transition from cylinders into vesicles at weak rate and the transition into vesicle-lamella mixtures with increased shear rate and lamella structures at the strong shear rate. Then, the average radius of gyration and shape factors of the polymer chains in the dynamic processes are discussed in detail. Results show that shear flow causes the structure of the polymer chains to be elongated along the shear direction, and the configuration of the polymer chain can be rapidly transformed into an ellipsoid structure under strong shear.

SUBMITTER: Shan Y

PROVIDER: S-EPMC6817888 | biostudies-other | 2019 Oct

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Shear-induced microstructures and dynamics processes of phospholipid cylinders in solutions.

Shan Yue Y Qiang Xiaowei X Ye Jianzhu J Wang Xianghong X He Linli L Li Shiben S

Scientific reports 20191028 1

Shear-induced microstructures and their corresponding dynamic processes are investigated for phospholipid cylinders in aqueous solution by dissipative particle dynamic simulation. Various phospholipid cylinders with cross-sections, which are formed under shear-free flow, are selected to examine the effects of shear flow on their structures and dynamic processes. Shear flow induces the transition from cylinders into vesicles at weak rate and the transition into vesicle-lamella mixtures with incre ...[more]

PMID: 31659204

Similar Datasets

Predicting asymmetric phospholipid microstructures in solutions.

Project description:Asymmetric phospholipid microstructures, such as asymmetric phospholipid membranes, have potential applications in biological and medicinal processes. Here, we used the dissipative particle dynamics simulation method to predict the asymmetric phospholipid microstructures in aqueous solutions. The asymmetric phospholipid membranes, tubes and vesicles are determined and characterized by the chain density distributions and order parameters. The phase diagrams are constructed to evaluate the effects of the chain length on the asymmetric structure formations at equilibrium states, while the average radius of gyration and shape factors are calculated to analyze the asymmetric structure formations in the non-equilibrium processes. Meanwhile, we predicted the mechanical properties of the asymmetric membranes by analyzing the spatial distributions of the interface tensions and osmotic pressures in solutions.

| S-EPMC9055179 | biostudies-literature

MONOMIALS AND BASIN CYLINDERS FOR NETWORK DYNAMICS.

Project description:We describe methods to identify cylinder sets inside a basin of attraction for Boolean dynamics of biological networks. Such sets are used for designing regulatory interventions that make the system evolve towards a chosen attractor, for example initiating apoptosis in a cancer cell. We describe two algebraic methods for identifying cylinders inside a basin of attraction, one based on the Groebner fan that finds monomials that define cylinders and the other on primary decomposition. Both methods are applied to current examples of gene networks.

| S-EPMC4299671 | biostudies-literature

Interaction of Macromolecular Chain with Phospholipid Membranes in Solutions: A Dissipative Particle Dynamics Simulation Study.

Project description:The interaction between macromolecular chains and phospholipid membranes in aqueous solution was investigated using dissipative particle dynamics simulations. Two cases were considered, one in which the macromolecular chains were pulled along parallel to the membrane surfaces and another in which they were pulled vertical to the membrane surfaces. Several parameters, including the radius of gyration, shape factor, particle number, and order parameter, were used to investigate the interaction mechanisms during the dynamics processes by adjusting the pulling force strength of the chains. In both cases, the results showed that the macromolecular chains undergo conformational transitions from a coiled to a rod-like structure. Furthermore, the simulations revealed that the membranes can be damaged and repaired during the dynamic processes. The role of the pulling forces and the adsorption interactions between the chains and membranes differed in the parallel and perpendicular pulling cases. These findings contribute to our understanding of the interaction mechanisms between macromolecules and membranes, and they may have potential applications in biology and medicine.

| S-EPMC10420874 | biostudies-literature

Cylinders vs. spheres: biofluid shear thinning in driven nanoparticle transport.

Project description:Increasingly, the research community applies magnetophoresis to micro and nanoscale particles for drug delivery applications and the nanoscale rheological characterization of complex biological materials. Of particular interest is the design and transport of these magnetic particles through entangled polymeric fluids commonly found in biological systems. We report the magnetophoretic transport of spherical and rod-shaped particles through viscoelastic, entangled solutions using lambda-phage DNA (?-DNA) as a model system. In order to understand and predict the observed phenomena, we fully characterize three fundamental components: the magnetic field and field gradient, the shape and magnetic properties of the probe particles, and the macroscopic rheology of the solution. Particle velocities obtained in Newtonian solutions correspond to macroscale rheology, with forces calculated via Stokes Law. In ?-DNA solutions, nanorod velocities are 100 times larger than predicted by measured zero-shear viscosity. These results are consistent with particles experiencing transport through a shear thinning fluid, indicating magnetically driven transport in shear thinning may be especially effective and favor narrow diameter, high aspect ratio particles. A complete framework for designing single-particle magnetic-based delivery systems results when we combine a quantified magnetic system with qualified particles embedded in a characterized viscoelastic medium.

| S-EPMC3858002 | biostudies-other

Shear induced carboplatin binding within the cavity of a phospholipid mimic for increased anticancer efficacy.

Project description:Vesicles 107 ± 19 nm in diameter, based on the self-assembly of tetra-para-phosphonomethyl calix[4]- arene bearing n-hexyl moieties attached to the phenolic oxygen centres, are effective in binding carboplatin within the cavity of the macrocycle under shear induced within a dynamic thin film in a continuous flow vortex fluidic device. Post shearing the vesicles maintain similar diameters and retain carboplatin within the cavity of the calixarene in a hierarchical structure, with their size and morphology investigated using DLS, TEM, SEM and AFM. Location of the carboplatin was confirmed using NMR, FTIR, ESI-MS and EFTEM, with molecular modelling favouring the polar groups of carboplatin hydrogen bonded to phosphonic acid moieties and the four member cyclobutane ring directed into the cavity of the calixarene. The loading efficiency and release profile of carboplatin was investigated using LC-TOF/MS, with the high loading of the drug achieved under shear and preferential released at pH 5.5, offering scope for anti-cancer drug delivery. The hierarchical structured vesicles increase the efficacy of carboplatin by 4.5 fold on ovarian cancer cells, lowered the IC50 concentration by 10 fold, and markedly increased the percent of cells in the S-phase (DNA replication) of the cell cycle.

| S-EPMC5386247 | biostudies-literature

Multiple Dynamic Processes Contribute to the Complex Steady Shear Behavior of Cross-Linked Supramolecular Networks of Semidilute Entangled Polymer Solutions.

Project description:Molecular theories of shear thickening and shear thinning in associative polymer networks are typically united in that they involve a single kinetic parameter that describes the network -- a relaxation time that is related to the lifetime of the associative bonds. Here we report the steady-shear behavior of two structurally identical metallo-supramolecular polymer networks, for which single-relaxation parameter models break down in dramatic fashion. The networks are formed by the addition of reversible cross-linkers to semidilute entangled solutions of PVP in DMSO, and they differ only in the lifetime of the reversible cross-links. Shear thickening is observed for cross-linkers that have a slower dissociation rate (17 s(-1)), while shear thinning is observed for samples that have a faster dissociation rate (ca. 1400 s(-1)). The difference in the steady shear behavior of the unentangled vs. entangled regime reveals an unexpected, additional competing relaxation, ascribed to topological disentanglement in the semidilute entangled regime that contributes to the rheological properties.

| S-EPMC2894477 | biostudies-literature

Shear-Induced Amyloid Formation in the Brain: I. Potential Vascular and Parenchymal Processes.

Project description:Shear distortion of amyloid-beta (A?) solutions accelerates amyloid cascade reactions that may yield different toxic oligomers than those formed in quiescent solutions. Recent experiments indicate that cerebrospinal fluid (CSF) and interstitial fluid (ISF) containing A? flow through narrow brain perivascular pathways and brain parenchyma. This paper suggests that such flow causes shear distortion of A? molecules involving conformation changes that may be one of the initiating events in the etiology of Alzheimer's disease. A? shearing can occur in or around brain arteries and arterioles and is suggested as the origin of cerebral amyloid angiopathy deposits in cerebrovascular walls. Comparatively low flow rates of ISF within the narrow extracellular spaces (ECS) of the brain parenchyma are suggested as a possible initiating factor in both the formation of neurotoxic A?42 oligomers and amyloid fibrils. A?42 in slow-flowing ISF can gain significant shear energy at or near the walls of tortuous brain ECS flow paths, promoting the formation of a shear-distorted, excited state hydrophobic A?42* conformation. This A?42* molecule could possibly be involved in one of two paths, one involving rapid adsorption to a brain membrane surface, ultimately forming neurotoxic oligomers on membranes, and the other ultimately forming plaque within the ECS flow pathways. Rising A? concentrations combined with shear at or near critical brain membranes are proposed as contributing factors to Alzheimer's disease neurotoxicity. These hypotheses may be applicable in other neurodegenerative diseases, including tauopathies and alpha-synucleinopathies, in which shear-distorted proteins also may form in the brain ECS.

| S-EPMC5026135 | biostudies-literature

Dynamics of shear-induced ATP release from red blood cells.

Project description:Adenosine triphosphate (ATP) is a regulatory molecule for many cell functions, both for intracellular and, perhaps less well known, extracellular functions. An important example of the latter involves red blood cells (RBCs), which help regulate blood pressure by releasing ATP as a vasodilatory signaling molecule in response to the increased shear stress inside arterial constrictions. Although shear-induced ATP release has been observed widely and is believed to be triggered by deformation of the cell membrane, the underlying mechanosensing mechanism inside RBCs is still controversial. Here, we use an in vitro microfluidic approach to investigate the dynamics of shear-induced ATP release from human RBCs with millisecond resolution. We demonstrate that there is a sizable delay time between the onset of increased shear stress and the release of ATP. This response time decreases with shear stress, but surprisingly does not depend significantly on membrane rigidity. Furthermore, we show that even though the RBCs deform significantly in short constrictions (duration of increased stress <3 ms), no measurable ATP is released. This critical timescale is commensurate with a characteristic membrane relaxation time determined from observations of the cell deformation by using high-speed video. Taken together our results suggest a model wherein the retraction of the spectrin-actin cytoskeleton network triggers the mechanosensitive ATP release and a shear-dependent membrane viscosity controls the rate of release.

| S-EPMC2575437 | biostudies-literature

Electric Field Enhances Shear Resistance of Polymer Melts via Orientational Polarization in Microstructures.

Project description:In this paper, we studied the alteration of viscoelastic properties of a neat poly(methyl methacrylate) (PMMA), induced by an applied external electric field. The rheological properties of PMMA are measured using a rotational rheometer at elevated temperatures. The electric field effect on the shear resistance of the polymer was studied by examining rheological responses under difference experimental scenarios. We find that the external electric field can remarkably enhance shear resistance and prevent flow of PMMA melt, enabling it to behave more predictably at high temperatures. Dynamic rheological analysis illustrates that the external electric field speeds up the recovery of mechanical properties of the PMMA melt after large deformations, whereas the PMMA melt exhibits thixotropic behaviors. The recovery velocity is influenced by the strength of the electric field, specifically, and is found to be proportional to the electric field strength. Our experimental characterization may provide new evidence on the tuning mechanical properties of polymer melts via controlling segmental polarization.

| S-EPMC7077492 | biostudies-literature

Shear-Induced Amyloid Formation in the Brain: II. An Experimental System for Monitoring Amyloid Shear Processes and Investigating Potential Spinal Tap Problems.

Project description:Liquid sheared amyloid-β (Aβ) initiates amyloid cascade reactions, producing unstable, potentially toxic oligomers. There is a need for new analytical tools with which to study these oligomers. A very small bore capillary flow system is proposed as a tool for studying the effects of liquid shear in amyloid research. This simple system consists of injecting a short cylindrical liquid sample plug containing dissolved amyloid into a liquid mobile phase flowing through an empty, very small internal diameter capillary tube. For liquid samples containing a single protein sample, under conditions in which there is laminar flow and limited sample protein molecular diffusion, chromatograms monitoring the optical protein absorbance of capillary effluent contain either one or two peaks, depending on the mobile phase flow rate. By controlling the sample diffusion times through changes in flow rate and/or capillary diameter, this tool can be used to generate aliquot samples with precise, reproducible amounts of shear for exploring the effects of variable shear on amyloid systems. The tool can be used for producing in-capillary stopped flow spectra of shear-stressed Aβ monomers as well as for kinetic studies of Aβ dimer- and oligomer-forming reactions between shear stressed Aβ monomers. Many other experiments are suggested using this experimental tool for studying the effects of shear on different Aβ and other amyloid systems, including testing for potentially serious amyloid sampling errors in spinal tap quantitative analysis. The technique has potential as both a laboratory research and a clinical tool.

| S-EPMC5523842 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data