scholarly journals Influence of Potassium Ions on Act of Amphotericin B to the DPPC/Chol Mixed Monolayer at Different Surface Pressures

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Juan Wang
Keyword(s):  
Amphotericin B ◽  
Mammalian Cell ◽  
Surface Pressure ◽  
High Pressures ◽  
High Surface ◽  
Potassium Ions ◽  
Molecular Area ◽  
Mixed Monolayer ◽  
Langmuir Blodgett Films ◽  
And Function

Amphotericin B (AmB) is an antifungal drug that rarely develops resistance. It has an affinity with the cholesterol on mammalian cell membranes, disrupting the structure and function of the membranes, which are also affected by potassium ions. However, the mechanism is unclear. In this paper, the Langmuir monolayer method was used to study the effects of potassium ions on the surface pressure–mean molecular area of isotherms, elastic modulus and the surface pressure–time curves of a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol (DPPC/Chol) monolayer and a DPPC/Chol/AmB monolayer. The morphology and thickness of the Langmuir–Blodgett films were studied via atomic force microscopy. The results showed that AmB can increase the mean molecular area of the DPPC/Chol mixed monolayer at low pressures (15 mN/m) but reduces it at high pressures (30 mN/m). The potassium ions may interfere with the effect of AmB in different ways. The potassium ions can enhance the influence of AmB on the stability of monolayer at low surface pressures, but weaken it at high surface pressures. The potassium ions showed significant interference with the interaction between AmB and the cholesterol-enriched region. The results are helpful for us to understand how the effect of amphotericin B on the phospholipid membrane is interfered with by potassium ions when amphotericin B enters mammalian cell membrane.

scholarly journals Effects of Carboxyl or Amino Group Modified InP/ZnS Nanoparticles Toward Simulated Lung Surfactant Membrane

2021 ◽  
Vol 9 ◽  
Author(s):  
Juan Wang ◽  
Shun Feng ◽  
Jie Liu ◽  
Rui-Lin Liu
Keyword(s):  
Elastic Modulus ◽  
Surface Pressure ◽  
Early Stage ◽  
Lung Surfactant ◽  
Optical Probe ◽  
Molecular Area ◽  
Mixed Monolayer ◽  
Toxicological Effects ◽  
Lung Health

Quantum dots (QDs) as a promising optical probe have been widely used for in vivo biomedical imaging; especially enormous efforts recently have focused on the potential toxicity of QDs to the human body. The toxicological effects of the representative InP/ZnS QDs as a cadmium-free emitter are still in the early stage and have not been fully unveiled. In this study, the DPPC/DPPG mixed monolayer was used to simulate the lung surfactant monolayer. The InP/ZnS-COOH QDs and InP/ZnS-NH2 QDs were introduced to simulate the lung surfactant membrane’s environment in the presence of InP/ZnS QDs. The effects of InP/ZnS QDs on the surface behavior, elastic modulus, and stability of DPPC/DPPG mixed monolayer were explored by the surface pressure-mean molecular area isotherms and surface pressure-time curves. The images observed by Brewster angle microscope and atomic force microscope showed that the InP/ZnS QDs affected the morphology of the monolayer. The results further demonstrated that the InP/ZnS QDs coated with different surface groups can obviously adjust the mean molecular area, elastic modulus, stability, and microstructure of DPPC/DPPG mixed monolayer. Overall, this work provided useful information for in-depth understanding of the effects of the −COOH or −NH2 group coated InP/ZnS QDs on the surface of lung surfactant membrane, which will help scientists to further study the physiological toxicity of InP/ZnS QDs to lung health.

scholarly journals Langmuir-Blodgett Films of Supported Polyester Dendrimers

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Rocío Redón ◽  
M. Pilar Carreón-Castro ◽  
F. J. Mendoza-Martínez
Keyword(s):  
Surface Pressure ◽  
Dendritic Structure ◽  
The Self ◽  
Langmuir Films ◽  
Interfacial Behavior ◽  
Brewster Angle Microscopy ◽  
Molecular Area ◽  
Langmuir Blodgett ◽  
Self Assembling ◽  
Langmuir Blodgett Films

Amphiphiles with a dendritic structure are attractive materials as they combine the features of dendrimers with the self-assembling properties and interfacial behavior of water-air affinities. We have synthesized three generations of polyester dendrimers and studied their interfacial properties on the Langmuir films. The behavior obtained was, as a rule, the lowest generation dendrimers behaving like traditional amphiphiles and the larger molecules presenting complicated isotherms. The Langmuir films of these compounds have been characterized by their surface pressure versus molecular area (π/A) and Brewster angle microscopy (BAM) observations.

Nanoporous activated biocarbons with high surface areas from alligator weed and their excellent performance for CO2 capture at both low and high pressures

2021 ◽  
Vol 406 ◽  
pp. 126787
Author(s):  
Gurwinder Singh ◽  
Rohan Bahadur ◽  
Jang Mee Lee ◽  
In Young Kim ◽  
Ajanya M. Ruban ◽  
...  
Keyword(s):  
Co2 Capture ◽  
High Pressures ◽  
High Surface ◽  
Excellent Performance ◽  
Alligator Weed ◽  
Surface Areas

Langmuir−Blodgett Films Formed by Continuously Varying Surface Pressure. Characterization by IR Spectroscopy and Epifluorescence Microscopy

Langmuir ◽  
2007 ◽  
Vol 23 (9) ◽  
pp. 4950-4958 ◽  
Author(s):  
Lin Wang ◽  
Antonio Cruz ◽  
Carol R. Flach ◽  
Jesús Pérez-Gil ◽  
Richard Mendelsohn
Keyword(s):  
Ir Spectroscopy ◽  
Surface Pressure ◽  
Epifluorescence Microscopy ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films

Conditions affecting the amphotericin B mediated inhibition of Candida albicans attachment to cell cultures

1989 ◽  
Vol 35 (2) ◽  
pp. 260-264 ◽  
Author(s):  
Glenn J. Merkel ◽  
Charles L. Phelps
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Mammalian Cell ◽  
Cell Cultures ◽  
Growth Phase ◽  
Mammalian Cells ◽  
Exponential Phase ◽  
Cell Interactions ◽  
Germ Tubes

Sublethal amounts of amphotericin B inhibited the attachment of Candida albicans to cultured mammalian cells. The extent of inhibition was influenced by the concentration of serum and the growth phase of the yeasts used to inoculate the cell cultures. Yeasts which were in their exponential phase of growth or had formed germ tubes were the most sensitive to amphotericin B. Equivalent amounts of amphotericin B inhibited yeast – mammalian cell interactions to different degrees depending upon the culture's tissue origin.Key words: Candida, amphotericin, polyenes, attachment, yeasts.

scholarly journals Surface pressure retrieval from SCIAMACHY measurements in the O<sub>2</sub> A Band: validation of the measurements and sensitivity on aerosols

2005 ◽  
Vol 5 (8) ◽  
pp. 2109-2120 ◽  
Author(s):  
B. van Diedenhoven ◽  
O. P. Hasekamp ◽  
I. Aben
Keyword(s):  
Surface Pressure ◽  
Radiation Transport ◽  
High Surface ◽  
Transport Processes ◽  
Calibration Error ◽  
Systematic Bias ◽  
Free Oxygen ◽  
Meteorological Models ◽  
Insight Into

Abstract. We perform surface pressure retrievals from cloud-free Oxygen A band measurements of SCIAMACHY. These retrievals can be well validated because surface pressure is a quantity that is, in general, accurately known from meteorological models. Therefore, surface pressure retrievals and their validation provide important insight into the quality of the instrument calibration. Furthermore, they can provide insight into retrievals which are affected by similar radiation transport processes, for example the retrieval of total columns of H2O, CO, CO2 and CH4. In our retrieval aerosols are neglected. Using synthetic measurements, it is shown that for low to moderate surface albedos this leads to an underestimation of the retrieved surface pressures. For high surface albedos this generally leads to an overestimation of the retrieved surface pressures. The surface pressures retrieved from the SCIAMACHY measurements indeed show this dependence on surface albedo, when compared to the corresponding pressures from a meteorological database. However, an offset of about 20 hPa was found, which can not be caused by neglecting aerosols in the retrieval. The same offset was found when comparing the retrieved surface pressures to those retrieved from co-located GOME Oxygen A band measurements. This implies a calibration error in the SCIAMACHY measurements. By adding an offset of 0.86% of the continuum reflectance at 756 nm to the SCIAMACHY reflectance measurements, this systematic bias vanishes.

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