Modeling the Formation of Liposomes with Vinpocetine from Soy Lecithin Phospholipids by Molecular Dynamics

Introduction. Liposomal preparations have the following advantages: they protect body cells from the toxic effects of drugs; prolong the action of the drug introduced into the body; protect medicinal substances from degradation; promote the manifestation of targeted specificity due to selective penetration from blood into tissues; change the pharmacokinetics of drugs, increasing their pharmacological effectiveness; allow you to create a water-soluble form of a number of medicinal substances, thereby increasing their bioavailability. The development of liposomal forms of vinpocetine is highly relevant. Currently, when developing the composition of liposomal forms, molecular modeling methods are widely used, which are a convenient method for predicting both the properties of the membranes themselves and aspects of the interaction of membranes with small molecules or proteins.Aim. The aim of this study is to model the process of liposome assembly from soy lecithin phospholipids in the presence of vinpocetine by the molecular dynamics method; as well as predicting the distribution of vinpocetine between the internal cavity of the liposome, the phospholipid membrane, and the dispersion medium based on the simulation results.Materials and methods. To simulate the process of liposome formation, the method of coarse-grained molecular dynamics in a Martini 2.2 force field was used using the Gromacs 2016.4 program. The assembly of the simulated system - a solution of soy lecithin phospholipids in water was performed using the Internet service Charmm-GUI-> Inputgenerator-> Martinimaker-> Randombuilder.Results and discussion. The results of molecular modeling showed that the vinpocetine molecules did not penetrate into the liposome, but were adsorbed on its surface. This is due to the low solubility of vipocetin in the hydrophobic medium of the soy lecithin liposome membrane.Conclusion. It was shown that the minimum diameter of a liposome formed from purified soy lecithin is 15.3 nm. Vinpocetine does not penetrate into liposomes from purified soy lecithin, but is adsorbed on the outer surface of their membrane. The surface excess in this case, according to the results of modeling coarse-grained molecular dynamics at a temperature of 298 K in an alcohol-water medium, is 1.2 • 10-7 mol/m2.

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Investigation of the Microscopic Viscoelastic Property for Cross-linked Polymer Network by Molecular Dynamics Simulation

Tire Science and Technology ◽

10.2346/1.3555178 ◽

2011 ◽

Vol 39 (1) ◽

pp. 44-58 ◽

Cited By ~ 3

Author(s):

Y. Masumoto ◽

Y. Iida

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Analytical Method ◽

Viscoelastic Properties ◽

Polymer Network ◽

Dynamics Simulation ◽

Coarse Grained ◽

The Cross ◽

Microscopic Dynamic ◽

Coarse Grained Molecular Dynamics

Abstract The purpose of this work is to develop a new analytical method for simulating the microscopic mechanical property of the cross-linked polymer system using the coarse-grained molecular dynamics simulation. This new analytical method will be utilized for the molecular designing of the tire rubber compound to improve the tire performances such as rolling resistance and wet traction. First, we evaluate the microscopic dynamic viscoelastic properties of the cross-linked polymer using coarse-grained molecular dynamics simulation. This simulation has been conducted by the coarse-grained molecular dynamics program in the OCTA) (http://octa.jp/). To simplify the problem, we employ the bead-spring model, in which a sequence of beads connected by springs denotes a polymer chain. The linear polymer chains that are cross-linked by the cross-linking agents express the three-dimensional cross-linked polymer network. In order to obtain the microscopic dynamic viscoelastic properties, oscillatory deformation is applied to the simulation cell. By applying the time-temperature reduction law to this simulation result, we can evaluate the dynamic viscoelastic properties in the wide deformational frequency range including the rubbery state. Then, the stress is separated into the nonbonding stress and the bonding stress. We confirm that the contribution of the nonbonding stress is larger at lower temperatures. On the other hand, the contribution of the bonding stress is larger at higher temperatures. Finally, analyzing a change of microscopic structure in dynamic oscillatory deformation, we determine that the temperature/frequency dependence of bond stress response to a dynamic oscillatory deformation depends on the temperature dependence of the average bond length in the equilibrium structure and the temperature/frequency dependence of bond orientation. We show that our simulation is a useful tool for studying the microscopic properties of a cross-linked polymer.

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Understanding the mechanical and viscoelastic properties of graphene reinforced polycarbonate nanocomposites using coarse-grained molecular dynamics simulations

Computational Materials Science ◽

10.1016/j.commatsci.2021.110339 ◽

2021 ◽

Vol 191 ◽

pp. 110339

Author(s):

Jie Yang ◽

Daniel Custer ◽

Cho Chun Chiang ◽

Zhaoxu Meng ◽

X.H. Yao

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Viscoelastic Properties ◽

Coarse Grained ◽

Dynamics Simulations ◽

Coarse Grained Molecular Dynamics

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Coarse-grained simulation of the self-assembly of lipid vesicles concomitantly with novel block copolymers with multiple tails

Soft Matter ◽

10.1039/d0sm01898h ◽

2021 ◽

Author(s):

Alexander Kantardjiev

Keyword(s):

Molecular Dynamics ◽

Block Copolymers ◽

Self Assembly ◽

Lipid Vesicles ◽

The Self ◽

Coarse Grained ◽

Copolymer Concentration ◽

Copolymer Structure ◽

Coarse Grained Molecular Dynamics

We carried out a series of coarse-grained molecular dynamics liposome-copolymer simulations with varying extent of copolymer concentration in an attempt to understand the effect of copolymer structure and concentration on vesicle self-assembly and stability.

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