Molecular Structure of Cefuroxime Axetil Complexes with α-, β-, γ-, and 2-Hydroxypropyl-β-Cyclodextrins: Molecular Simulations and Raman Spectroscopic and Imaging Studies

The formation of cefuroxime axetil+cyclodextrin (CA+CD) complexes increases the aqueous solubility of CA, improves its physico-chemical properties, and facilitates a biomembrane-mediated drug delivery process. In CD-based tablet formulations, it is crucial to investigate the molecular details of complexes in final pharmaceutical preparation. In this study, Raman spectroscopy and mapping were applied for the detection and identification of chemical groups involved in α-, β-, γ-, and 2-hydroxypropyl-β-CD (2-HP- β-CD)+CA complexation process. The experimental studies have been complemented by molecular dynamics-based investigations, providing additional molecular details of CA+CD interactions. It has been demonstrated that CA forms the guest–host type inclusion complexes with all studied CDs; however, the nature of the interactions is slightly different. It seems that both α- and β-CD interact with furanyl and methoxy moieties of CA, γ-CD forms a more diverse pattern of interactions with CA, which are not observed in other CDs, whereas 2HP-β-CD binds CA with the contribution of hydrogen bonding. Apart from supporting this interpretation of the experimental data, molecular dynamics simulations allowed for ordering the CA+CD binding affinities. The obtained results proved that the molecular details of the host–guest complexation can be successfully predicted from the combination of Raman spectroscopy and molecular modeling.

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Effects of fluoride salt addition to the physico-chemical properties of the MgCl2-NaCl-KCl heat transfer fluid : a molecular dynamics study

10.26434/chemrxiv-2021-kjqcx ◽

2021 ◽

Author(s):

Weiguang Zhou ◽

Yanping Zhang ◽

Mathieu Salanne

Keyword(s):

Heat Transfer ◽

Molecular Dynamics ◽

Experimental Studies ◽

Chemical Properties ◽

Heat Transfer Fluid ◽

Electricity Production ◽

Fluoride Ions ◽

Heat Transfer Fluids ◽

Physico Chemical ◽

Dynamics Simulations

Concentrated solar plants are promising solutions for electricity production. In these plants, the heat transfer fluid plays an important role, and finding systems with good thermal properties is very important. In this regard, molten salts, and more particularly molten chlorides, are currently investigated. Experimental studies of these melts are difficult and expensive, so complementing them with simulations would allow to test a wider range of compositions. In this work, we show that classical molecular dynamics simulations are suitable for predicting the properties of a ternary salt composed of MgCl2, KCl and NaCl by extensive comparisons with experimental data (and previous simulations) on the density, heat capacity, viscosity and thermal conductivity. We then study the effect of adding fluoride ions in the melt on these properties in order to investigate the suitability of mixed chlorides-fluorides for future heat transfer fluids studies.

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Molecular dynamics simulations and experimental studies reveal differential permeability of withaferin-A and withanone across the model cell membrane

Scientific Reports ◽

10.1038/s41598-021-81729-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Renu Wadhwa ◽

Neetu Singh Yadav ◽

Shashank P. Katiyar ◽

Tomoko Yaguchi ◽

Chohee Lee ◽

...

Keyword(s):

Molecular Dynamics ◽

Cell Membrane ◽

Molecular Dynamics Simulations ◽

Experimental Studies ◽

Bilayer Membrane ◽

Withaferin A ◽

Head Group ◽

Polar Head Group ◽

Natural Drugs ◽

Dynamics Simulations

AbstractPoor bioavailability due to the inability to cross the cell membrane is one of the major reasons for the failure of a drug in clinical trials. We have used molecular dynamics simulations to predict the membrane permeability of natural drugs—withanolides (withaferin-A and withanone) that have similar structures but remarkably differ in their cytotoxicity. We found that whereas withaferin-A, could proficiently transverse through the model membrane, withanone showed weak permeability. The free energy profiles for the interaction of withanolides with the model bilayer membrane revealed that whereas the polar head group of the membrane caused high resistance for the passage of withanone, the interior of the membrane behaves similarly for both withanolides. The solvation analysis further revealed that the high solvation of terminal O5 oxygen of withaferin-A was the major driving force for its high permeability; it interacted with the phosphate group of the membrane that led to its smooth passage across the bilayer. The computational predictions were tested by raising and recruiting unique antibodies that react to withaferin-A and withanone. The time-lapsed analyses of control and treated cells demonstrated higher permeation of withaferin-A as compared to withanone. The concurrence between the computation and experimental results thus re-emphasised the use of computational methods for predicting permeability and hence bioavailability of natural drug compounds in the drug development process.

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Nanoformulation-by-design: an experimental and molecular dynamics study for polymer coated drug nanoparticles

RSC Advances ◽

10.1039/d0ra00408a ◽

2020 ◽

Vol 10 (33) ◽

pp. 19521-19533 ◽

Cited By ~ 3

Author(s):

Ioanna Danai Styliari ◽

Vincenzo Taresco ◽

Andrew Theophilus ◽

Cameron Alexander ◽

Martin Garnett ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Experimental Studies ◽

High Drug ◽

Nanoparticle Formation ◽

Polymer Nanoparticle ◽

Drug Nanoparticles ◽

Dynamics Simulations

Experimental studies of drug–polymer nanoparticle formation combined with molecular dynamics simulations provide atomistic explanations for the high drug loadings obtained.

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The study of aqueous isopropanol solutions at various concentrations: low frequency Raman spectroscopy and molecular dynamics simulations

Journal of Molecular Structure ◽

10.1016/s0022-2860(03)00107-8 ◽

2003 ◽

Vol 651-653 ◽

pp. 271-275 ◽

Cited By ~ 20

Author(s):

A. Idrissi ◽

S. Longelin

Keyword(s):

Molecular Dynamics ◽

Raman Spectroscopy ◽

Molecular Dynamics Simulations ◽

Low Frequency ◽

Dynamics Simulations ◽

Aqueous Isopropanol

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Effect of Chain Conformational Change on Micelle Structures: Experimental Studies and Molecular Dynamics Simulations

The Journal of Physical Chemistry B ◽

10.1021/jp076939p ◽

2008 ◽

Vol 112 (3) ◽

pp. 776-783 ◽

Cited By ~ 46

Author(s):

Weiwei Ding ◽

Shaoliang Lin ◽

Jiaping Lin ◽

Liangshun Zhang

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Conformational Change ◽

Experimental Studies ◽

Dynamics Simulations

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Experimental Studies and Molecular Dynamics Simulations of the Sliding Contact of Metallic Glass

MRS Proceedings ◽

10.1557/proc-644-l1.8 ◽

2000 ◽

Vol 644 ◽

Cited By ~ 1

Author(s):

Xi-Yong Fu ◽

Michael L. Falk ◽

David A. Rigney

Keyword(s):

Molecular Dynamics ◽

Metallic Glass ◽

Molecular Dynamics Simulations ◽

Bulk Metallic Glass ◽

Amorphous Material ◽

Experimental Studies ◽

Sliding Contact ◽

Atomic Scale ◽

Sliding Interface ◽

Dynamics Simulations

AbstractTribological properties of bulk metallic glass Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 were studied experimentally using a pin/disk geometry without lubrication. Experimental observations were compared with 2D molecular dynamics simulations of amorphous material in sliding contact. The friction coefficient and the wear rate of bulk metallic glass (BMG) depend on normal load and test environment. The sliding of annealed BMG re-amorphizes devitrified material. A mechanically mixed layer is generated during sliding; this layer has enhanced oxygen content if the sliding is in air. The MD simulations show that atomic scale mixing occurs across the sliding interface. The growth kinetics of the mixing process scales with the square root of time. In the simulations, a low density region is generated near the sliding interface; it corresponds spatially to the softer layer detected in experiments. Subsurface displacement profiles produced by sliding and by simulation are very similar and are consistent with the flow patterns expected from a simple Navier-Stokes analysis when the stress state involves both compression and shear.

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