External surface structure of organoclays analyzed by transmission electron microscopy and X-ray photoelectron spectroscopy in combination with molecular dynamics simulations

2016 ◽  
Vol 478 ◽  
pp. 188-200 ◽  
Author(s):  
B. Schampera ◽  
D. Tunega ◽  
R. Šolc ◽  
S.K. Woche ◽  
R. Mikutta ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Dynamics ◽  
Transmission Electron Microscopy ◽  
Molecular Dynamics Simulations ◽  
Surface Structure ◽  
Photoelectron Spectroscopy ◽  
External Surface ◽  
X Ray ◽  
Transmission Electron ◽  
Dynamics Simulations

scholarly journals Abstract P-2: Multiscale Molecular Dynamics Simulations of the Skin Membranes as a Tool for the Interpretation of the Transmission Electron Microscopy Images

2021 ◽  
Vol 11 (Suppl_1) ◽  
pp. S11-S11
Author(s):  
Marine Bozdaganyan
Keyword(s):  
Electron Microscopy ◽  
Molecular Dynamics ◽  
Transmission Electron Microscopy ◽  
Linoleic Acid ◽  
Molecular Dynamics Simulations ◽  
Coarse Grained ◽  
Water Model ◽  
Active Ingredients ◽  
Transmission Electron ◽  
Dynamics Simulations

Background: Human skin can inhibit chemical penetration which limits the clinical applications of transdermal drug delivery. The stratum corneum (SC) is the primary barrier and organized in lamellar membranes containing the lipids of ceramides (CER), free fatty acids (FFA), and cholesterol (CHOL). One of the most widely used ways to overcome the SC is the addition of chemical penetration enhancers (CPEs) to active ingredients. There are various methods, which have been employed to explore the mechanisms by which CPEs with drugs can change the morphology of SC including transmission electron microscopy. Here, we propose to use multiscale coarse-grained (CG) molecular dynamics (MD) simulations for the interpretation of the images of the SC from the electron microscopy experiments. Methods: We utilized the MARTINI force field for the CG simulations. We employed the mixed-lipid bilayer model of SC consisting of CER, CHOL, and FFA in a 1:1:1 molar ratio assembled with CHARMM-GUI web-service. The systems of the SC model membrane and various enhancers were simulated in the NPT ensemble with the polarizable water model and the reaction field approach for the long-range electrostatics with the usage of Gromacs 2019.4 software. Results: The membrane model was validated with standard characteristics: thickness, diffusion of the lipids, order parameters, and density profiles. After, we have added CPEs and active ingredients to the systems: menthol and osthole as control simulations, ethanol with linoleic acid and lidocaine as test simulations. We have observed the membrane desegregation in the case of menthol and osthole formulations similar to the published results while the permeation of lidocaine with ethanol and linoleic acid did not cause the disruption of the membranes but increased its fluidity and permeability properties. Conclusion: The method of multiscale coarse-grained molecular dynamics simulations can be utilized for the prediction and interpretation of morphology change of SC in addition to various substances.

scholarly journals Quantitative interpretation of molecular dynamics simulations for X-ray photoelectron spectroscopy of aqueous solutions

2016 ◽  
Vol 144 (15) ◽  
pp. 154704 ◽  
Author(s):  
Giorgia Olivieri ◽  
Krista M. Parry ◽  
Cedric J. Powell ◽  
Douglas J. Tobias ◽  
Matthew A. Brown
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solutions ◽  
Molecular Dynamics Simulations ◽  
Photoelectron Spectroscopy ◽  
Quantitative Interpretation ◽  
X Ray ◽  
Dynamics Simulations

scholarly journals 3D Modeling of Silver Doped ZrO2 Coupled Graphene-Based Mesoporous Silica Quaternary Nanocomposite for a Nonenzymatic Glucose Sensing Effects

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 193
Author(s):  
Kamrun Nahar Fatema ◽  
Chang-Sung Lim ◽  
Yin Liu ◽  
Kwang-Youn Cho ◽  
Chong-Hun Jung ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mesoporous Silica ◽  
Photoelectron Spectroscopy ◽  
Glucose Sensor ◽  
Diffuse Reflectance Spectroscopy ◽  
Active Material ◽  
Glucose Sensing ◽  
X Ray ◽  
Transmission Electron

We described the novel nanocomposite of silver doped ZrO2 combined graphene-based mesoporous silica (ZrO2-Ag-G-SiO2,) in bases of low-cost and self-assembly strategy. Synthesized ZrO2-Ag-G-SiO2 were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Diffuse Reflectance Spectroscopy (DRS). The ZrO2-Ag-G-SiO2 as an enzyme-free glucose sensor active material toward coordinate electro-oxidation of glucose was considered through cyclic voltammetry in significant electrolytes, such as phosphate buffer (PBS) at pH 7.4 and commercial urine. Utilizing ZrO2-Ag-G-SiO2, glucose detecting may well be finished with effective electrocatalytic performance toward organically important concentrations with the current reaction of 9.0 × 10−3 mAcm−2 and 0.05 mmol/L at the lowest potential of +0.2 V, thus fulfilling the elemental prerequisites for glucose detecting within the urine. Likewise, the ZrO2-Ag-G-SiO2 electrode can be worked for glucose detecting within the interferometer substances (e.g., ascorbic corrosive, lactose, fructose, and starch) in urine at proper pH conditions. Our results highlight the potential usages for qualitative and quantitative electrochemical investigation of glucose through the ZrO2-Ag-G-SiO2 sensor for glucose detecting within the urine concentration.

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