Interaction of Particles with the Pulmonary Interface: Effects on Surface Elasticity

2014 ◽  
Vol 658 ◽  
pp. 459-464
Author(s):  
Bogdan Munteanu ◽  
Yves Berthier ◽  
Jean Paul Rieu ◽  
Ana Maria Trunfio-Sfarghiu

We present an experimental study of the interactions of negative and positive model particles and their influence on the surface elasticity of biomimetic pulmonary surfactant. In this purpose we have measured the adhesion force between negative (G) and positive (GS) particles and supported lipid bilayer by Atomic Force Spectroscopy. In addition, the modification in surface elasticity of lipid monolayer under quasistatic compression when interacting with negative and positive particles was investigated on a Langmuir trough. We found that, positive particles interact poorly with biomimetic pulmonary surfactant, therefore no modifications in surface elasticity were observed. Conversely, negative charged particles interact strongly with the biomimetic pulmonary surfactant, decreasing the surface elasticity. The results are directly relevant for understanding the interactions and the effects of particulate matter on pulmonary structures which could lead to pulmonary surfactant inhibition or deficiency causing severe respiratory distress or pathologies.

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 900
Author(s):  
Maria Vardaki ◽  
Aida Pantazi ◽  
Ioana Demetrescu ◽  
Marius Enachescu

In this work we present the results of a functional properties assessment via Atomic Force Microscopy (AFM)-based surface morphology, surface roughness, nano-scratch tests and adhesion force maps of TiZr-based nanotubular structures. The nanostructures have been electrochemically prepared in a glycerin + 15 vol.% H2O + 0.2 M NH4F electrolyte. The AFM topography images confirmed the successful preparation of the nanotubular coatings. The Root Mean Square (RMS) and average (Ra) roughness parameters increased after anodizing, while the mean adhesion force value decreased. The prepared nanocoatings exhibited a smaller mean scratch hardness value compared to the un-coated TiZr. However, the mean hardness (H) values of the coatings highlight their potential in having reliable mechanical resistances, which along with the significant increase of the surface roughness parameters, which could help in improving the osseointegration, and also with the important decrease of the mean adhesion force, which could lead to a reduction in bacterial adhesion, are providing the nanostructures with a great potential to be used as a better alternative for Ti implants in dentistry.


2000 ◽  
Vol 40 (supplement) ◽  
pp. S80
Author(s):  
H. Kim ◽  
T. Osada ◽  
A. Ikai

2010 ◽  
Vol 13 (3) ◽  
pp. 1029-1037 ◽  
Author(s):  
Lijin Xia ◽  
Scott C. Lenaghan ◽  
Mingjun Zhang ◽  
Yu Wu ◽  
Xiaopeng Zhao ◽  
...  

2004 ◽  
Vol 49 (2) ◽  
pp. 183-190 ◽  
Author(s):  
S. Dunn ◽  
S. Impey ◽  
C. Kimpton ◽  
S.A. Parsons ◽  
J. Doyle ◽  
...  

Stainless steel, polymethylmethacrylate and polytetrafluoroethylene coupons were analysed for surface topographical and adhesion force characteristics using tapping mode atomic force microscopy and force-distance microscopy techniques. The two polymer materials were surface modified by polishing with silicon carbide papers of known grade. The struvite scaling rate was determined for each coupon and related to the data gained from the surface analysis. The scaling rate correlated well with adhesion force measurements indicating that lower energy materials scale at a lower rate. The techniques outlined in the paper provide a method for the rapid screening of materials in potential scaling applications.


2019 ◽  
Vol 36 (4) ◽  
pp. 160-164
Author(s):  
Yidong Zhang

Purpose The purpose of this paper is to investigate the nanoscale electric performance of NiO thin films in grain boundary and grain face. Design/methodology/approach PeakForce tunnel atomic force is applied to visualize the nanoscale current imaging of the NiO thin film on fluorine tin oxide substrate. Findings The results show that the grain boundary has a significant impact on the nanoscale current of the NiO film. The electronic conductivity and in grain boundary is higher than that of the NiO film in grain face. The width of the conductive zone in the NiO film over grain boundaries is ∼ 60 nm. The tunnel current between the tip and the NiO film is consistent with the Fowler–Nordheim tunnel model. Originality/value The higher tunnel current in grain boundary is probably attributed to the enhanced energy band bending and adhesion force.


RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 25789-25798 ◽  
Author(s):  
Sumit Arora ◽  
Michael Kappl ◽  
Mehra Haghi ◽  
Paul M. Young ◽  
Daniela Traini ◽  
...  

l-Leucine modified voriconazole spray dried micropartcles.


2016 ◽  
Vol 3 (10) ◽  
pp. 160248 ◽  
Author(s):  
X. Jin ◽  
B. Kasal

This study attempts to address the interpretation of atomic force microscopy (AFM) adhesion force measurements conducted on the heterogeneous rough surface of wood and natural fibre materials. The influences of wood surface roughness, tip geometry and wear on the adhesion force distribution are examined by cyclic measurements conducted on wood surface under dry inert conditions. It was found that both the variation of tip and surface roughness of wood can widen the distribution of adhesion forces, which are essential for data interpretation. When a common Si AFM tip with nanometre size is used, the influence of tip wear can be significant. Therefore, control experiments should take the sequence of measurements into consideration, e.g. repeated experiments with used tip. In comparison, colloidal tips provide highly reproducible results. Similar average values but different distributions are shown for the adhesion measured on two major components of wood surface (cell wall and lumen). Evidence supports the hypothesis that the difference of the adhesion force distribution on these two locations was mainly induced by their surface roughness.


Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 358
Author(s):  
Hongling Zhang ◽  
Jinshao Ye ◽  
Huaming Qin ◽  
Xujun Liang ◽  
Yan Long

Triphenyltin (TPT) has severely polluted the environment, and it often coexists with metal ions, such as Cu2+. This paper describes the cell’s molecular recognition of TPT, the interaction between TPT recognition and Cu2+ biosorption, and their effect on cell permeability. We studied the recognition of TPT by Bacillus thuringiensis cells and the effect of TPT recognition on Cu2+ biosorption by using atomic force microscopy to observe changes in cell surface mechanical properties and cellular morphology and by using flow cytometry to determine the cell growth status and cell permeability. The results show that B. thuringiensis can quickly recognize different media. The adhesion force of cells in contact with Tween 80 was significantly reduced to levels that were much lower than that of cells in contact with PBS. Conversely, the cell surface adhesion force increased as TPT became more degraded. B. thuringiensis cells maintained their original morphology after 48 h of TPT treatment. The amount of Cu2+ adsorption by TPT-treated cells was positively correlated with the surface adhesion force (r = 0.966, P = 0.01). The cell adhesion force significantly decreased after Cu2+ adsorption, and cell recognition of TPT and/or Cu2+ hindered the entrance of 2’,7’-dichlorodihydrofluorescein diacetate (DCFH-DA) into the cell. The initial diffusion time of DCFH-DA into cells treated by PBS, Cu2+, TPT, and TPT+Cu2+ was 4, 10, 30, and 30 min, respectively, and the order of the fluorescence intensity was PBS >> Cu2+ > TPT > TPT+Cu2+. We conclude that changes in the cell surface properties of the microbe during recognition of pollutants depend on the contaminant’s properties. B. thuringiensis recognized TPT and secreted intracellular substances that not only enhanced the adsorption of Cu2+, but also formed a “barrier” on the cell surface that reduced permeability. These findings provide a novel insight into the mechanism of microbial removal of pollutants.


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