scholarly journals Influence of Laser-Designed Microstructure Density on Interface Characteristics and on Preliminary Responses of Epithelial Cells

2020 ◽  
Vol 10 (18) ◽  
pp. 6299
Author(s):  
Anca Bonciu ◽  
Alixandra Wagner ◽  
Valentina Marascu ◽  
Antoniu Moldovan ◽  
Cerasela Zoica Dinu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cellular Response ◽  
Force Microscopy ◽  
Cellular Effects ◽  
Atomic Force ◽  
Interface Characteristics ◽  
Topographical Distribution ◽  
Krf Excimer Laser ◽  
And Migration ◽  
Microstructure Density

Current trends in designing medical and tissue engineering systems rely on the incorporation of micro- and nano-topographies for inducing a specific cellular response within the context of an aimed application. As such, dedicated studies have recently focused on understanding the possible effects of high and low density packed topographies on the behavior of epithelial cells, especially when considering their long-term viability and functionality. We proposed to use stair-like designed topographies with three different degrees of distribution, all created in polydimethylsiloxane (PDMS) as active means to monitor cell behavior. Our model cellular system was human bronchial epithelial cells (BEAS-2B), a reference line in the quality control of mesenchymal stem cells (MSCs). PDMS microtextured substrates of 4 µm square unit topographies were created using a mold design implemented by a KrF Excimer laser. Varying the spacing between surface features and their multiscale level distribution led to irregular stairs/lines in low, medium and high densities, respectively. Profilometry, scanning electron and atomic force microscopy, contact angle and surface energy measurements were performed to evaluate the topographical and interface characteristics of the designed surfaces, while density-induced cellular effects were investigated using traditional cell-based assays. Our analysis showed that microstructure topographical distribution influences the adhesion profiles of epithelial cells. Our analysis hint that epithelial organoid formation might be initiated by the restriction of cell spreading and migration when using user-designed, controlled micro-topographies on engineered surfaces.

scholarly journals Localized elasticity measured in epithelial cells migrating at a wound edge using atomic force microscopy

2008 ◽  
Vol 295 (1) ◽  
pp. L54-L60 ◽  
Author(s):  
Ajay A. Wagh ◽  
Esra Roan ◽  
Kenneth E. Chapman ◽  
Leena P. Desai ◽  
David A. Rendon ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Wound Healing ◽  
Epithelial Cells ◽  
Cell Spreading ◽  
Dominant Negative ◽  
Cell Stiffness ◽  
Wound Edge ◽  
Force Microscopy ◽  
Atomic Force ◽  
And Migration

Restoration of lung homeostasis following injury requires efficient wound healing by the epithelium. The mechanisms of lung epithelial wound healing include cell spreading and migration into the wounded area and later cell proliferation. We hypothesized that mechanical properties of cells vary near the wound edge, and this may provide cues to direct cell migration. To investigate this hypothesis, we measured variations in the stiffness of migrating human bronchial epithelial cells (16HBE cells) ∼2 h after applying a scratch wound. We used atomic force microscopy (AFM) in contact mode to measure the cell stiffness in 1.5-μm square regions at different locations relative to the wound edge. In regions far from the wound edge (>2.75 mm), there was substantial variation in the elastic modulus in specific cellular regions, but the median values measured from multiple fields were consistently lower than 5 kPa. At the wound edge, cell stiffness was significantly lower within the first 5 μm but increased significantly between 10 and 15 μm before decreasing again below the median values away from the wound edge. When cells were infected with an adenovirus expressing a dominant negative form of RhoA, cell stiffness was significantly decreased compared with cells infected with a control adenovirus. In addition, expression of dominant negative RhoA abrogated the peak increase in stiffness near the wound edge. These results suggest that cells near the wound edge undergo localized changes in cellular stiffness that may provide signals for cell spreading and migration.

Fabrication of GaN Doped ZnO Nanocrystallines by Laser Ablation

2008 ◽  
Vol 8 (8) ◽  
pp. 4168-4171
Author(s):  
N. Gopalakrishnan ◽  
B. C. Shin ◽  
K. P. Bhuvana ◽  
J. Elanchezhiyan ◽  
T. Balasubramanian
Keyword(s):  
Deep Level ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Doped Zno ◽  
Krf Excimer Laser ◽  
Photoluminescence Studies

Here, we present the fabrication of pure and GaN doped ZnO nanocrystallines on Si(111) substrates by KrF excimer laser. The targets for the ablation have been prepared by conventional ceramic method. The fabricated nanocrystallines have been investigated by X-ray diffraction, photoluminescence and atomic force microscopy. The X-ray diffraction analysis shows that the crystalline size of pure ZnO is 36 nmand it is 41 nmwhile doped with 0.8 mol% of GaN due to best stoichiometry between Zn and O. Photoluminescence studies reveal that intense deep level emissions have been observed for pure ZnO and it has been suppressed for the GaN doped ZnO structures. The images of atomic force microscope show that the rms surface roughness is 27 nm for pure ZnO and the morphology is improved with decrease in rms roughness, 18 nm with fine crystallines while doped with 1 mol% GaN. The improved structural, optical and morphological properties of ZnO nanocrystalline due to GaN dopant have been discussed in detail.

Living Renal Epithelial Cells Imaged by Atomic Force Microscopy

Nephron ◽  
1994 ◽  
Vol 66 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Hans Oberleithner ◽  
Albrecht Schwab ◽  
Wenhui Wang ◽  
Gerhard Giebisch ◽  
Forest Hume ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Epithelial Cells ◽  
Renal Epithelial Cells ◽  
Force Microscopy ◽  
Atomic Force

Cellular effects of magnetic nanoparticles explored by atomic force microscopy

2015 ◽  
Vol 3 (9) ◽  
pp. 1284-1290 ◽  
Author(s):  
Hongli Mao ◽  
Jingchao Li ◽  
Ida Dulińska-Molak ◽  
Naoki Kawazoe ◽  
Yoshihiko Takeda ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Magnetic Nanoparticles ◽  
Force Microscopy ◽  
Cellular Effects ◽  
Atomic Force

Atomic force microscopy (AFM) was used to explore the cellular effects caused by magnetic nanoparticles.

Alkaline Stress-Induced Cell Transformation

Physiology ◽  
1994 ◽  
Vol 9 (3) ◽  
pp. 165-168
Author(s):  
H Oberleithner ◽  
A Schwab
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Migration ◽  
Epithelial Cells ◽  
Cell Transformation ◽  
Alkaline Stress ◽  
Membrane Turnover ◽  
Force Microscopy ◽  
Cells In Culture ◽  
Atomic Force

Sustained alkalosis transforms epithelial cells in culture. Genotypically altered cells express an endogenous Ca2+ oscillator that probably is the motor for restless locomotion of these cells. Atomic force microscopy discloses membrane turnover processes during cell migration at the nanometer level.

Alkaline Stress-Induced Cell Transformation

Physiology ◽  
1994 ◽  
Vol 9 (4) ◽  
pp. 165-168
Author(s):  
Hans Oberleithner ◽  
Albrecht Schwab
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Migration ◽  
Epithelial Cells ◽  
Cell Transformation ◽  
Alkaline Stress ◽  
Membrane Turnover ◽  
Force Microscopy ◽  
Cells In Culture ◽  
Atomic Force

Sustained alkalosis transforms epithelial cells in culture. Genotypically altered cells express an endogenous Ca2+ oscillator that probably is the motor for restless locomotion of these cells. Atomic force microscopy discloses membrane turnover processes during cell migration at the nanometer level.

scholarly journals Atomic Force Microscopy for the Characterisation of the Effects and Treatment of Infectious Parasites

2013 ◽  
Vol 19 (S4) ◽  
pp. 3-4
Author(s):  
P. Eaton ◽  
J.R.S.A. Leite ◽  
C. Bittencourt ◽  
M. Prudêncio ◽  
M.J. Feio ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Morphology ◽  
Low Income ◽  
Cellular Response ◽  
Parasitophorous Vacuole ◽  
Membrane Integrity ◽  
Liver Cells ◽  
Low Income Countries ◽  
Force Microscopy ◽  
Atomic Force

In this talk the utility of atomic force microscopy (AFM) for research into infectious parasites will be discussed. AFM has grown from relatively recent beginnings to become an extremely powerful technique in the life sciences, coupling high resolution imaging with a range of non-imaging experiments. Importantly, these experiments can be performed in situ, even on individual molecules or on live cells.The two examples discussed relate to the important diseases leishmaniasis and malaria. Leishmaniasis is a disease caused by the protozoan parasite of the Leishmania genera, and causes approximately 60,000 deaths per year. Despite the high death toll, the disease has been the subject of relatively little research and little treatment is available, probably because the most severe cases are confined to developing nations. The most severe form, visceral leishmaniasis is caused by the species known as Leishmania infantum (syn. L. chagasi). A promising new anti-leishmania drug, DS01 has been recently isolated from amphibian secretions and can kill L. infantum in low concentrations. We were able to culture and prepare for microscopy L. infantum promastigotes for the first time, as well as to study the effects of DS01 on cell morphology and membrane integrity. The results from both AFM and SEM are highly complementary and illustrate the possibility of membrane-focussed activity as well as the possibility of attack on the flagella (figure 1).Malaria is one of the most deadly diseases in the world, killing more than 600,000 people per year, mostly in low-income countries. It is caused by Plasmodium parasites, and the most commonly studied stage is that in which the parasite invades the blood. Prior to blood invasion, the parasites infect hepatocytes in the liver, with formation of a parasitophorous vacuole, where they develop into exoerythrocytic forms and multiply to generate thousands of merozoites, later released into the bloodstream and causing disease. However, infection of liver cells, which is clinically silent, is required for disease progression. We studied infection of liver cells by Plasmodium using combined epifluorescence and atomic force microscopy. We observed significant changes in cell morphology as infection progressed (figure 2). Furthermore we made nanoindentation measurements with the AFM, to determine cellular stiffness. We observed stiffening of the cells after 48 hours of infection compared to uninfected cells. This was a cellular response to the Plasmodium infection, rather than a result of the stiffness of the invading parasites themselves. This stiffening may be caused by reinforcement of cytoskeletal structures, and we believe this may reflect a self-defence mechanism by the cell itself.

Investigation of Surface Grooves from Migrating Grain Boundaries

2002 ◽  
Vol 750 ◽  
Author(s):  
Nicole E. Munoz ◽  
Shelley R. Gilliss ◽  
N. Ravishankar ◽  
C. Barry Carter
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Boundary ◽  
Light Microscopy ◽  
Grain Boundaries ◽  
High Purity ◽  
Moving Boundary ◽  
Migration Process ◽  
Force Microscopy ◽  
Atomic Force ◽  
And Migration

ABSTRACTVisible-light microscopy (VLM) and atomic-force microscopy (AFM) were used to study the progression of grain-boundary grooving and migration in high-purity alumina (Lucalox™). Groove profiles from the same grain boundaries were revisited using AFM following successive heat-treatments. The grooves measured from migrating grain boundaries were found to have asymmetric partial-angles compared to those measured from boundaries that did not migrate during the experiment. For a moving boundary, the grain with the larger partial-angle was consistently found to grow into the grain with the smaller partial-angle. Migrating boundaries were observed to leave behind remnant thermal grooves. The observations indicate that the boundary may be bowing out during the migration process.

Computational Studies of Droplet Motion Near a Rough Surface via 3D Spectral Boundary Elements

2019 ◽  
Author(s):  
Yechun Wang ◽  
Xinnan Wang
Keyword(s):  
Shear Flow ◽  
Rough Surface ◽  
Theoretical Foundation ◽  
Liquid Droplet ◽  
Droplet Motion ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sinusoidal Functions ◽  
Parabolic Flow ◽  
And Migration

Abstract A plethora of studies have investigated the motion of a liquid droplet in the vicinity of a smooth surface, incurred by shear flow, parabolic flow or gravity. However, there are few studies that consider the roughness of the surface that could affect the droplet motion. In this study, we employ a 3D spectral boundary element method for interfacial dynamics to examine the droplet translation, migration, and deformation in the vicinity of a rough surface due to shear flow. The roughness feature of the surface is comparable to the size of the droplet and is simulated with sinusoidal functions. Topologies of epoxy coating surfaces are also considered in the computations. The roughness and profile of the coating surface is obtained by atomic force microscopy. The computational results show that the surface roughness affects significantly the behavior of a deformable droplet near the surface, including its deformation and migration speed. In return, the dynamics of the droplet also influences the stress distribution on the rough surface. The results of this study could provide theoretical foundation in the prediction of particle induced erosion corrosion of organic coatings.

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