scholarly journals Nanomechanics of hard films on compliant substrates.

2009 ◽  
Author(s):  
Earl David, Jr. Reedy ◽  
John Allen Emerson ◽  
David F. Bahr ◽  
Neville Reid Moody ◽  
Xiao Wang Zhou ◽  
...  
Keyword(s):  
Compliant Substrates

scholarly journals Substrate stiffness modulates integrin α5 expression and ECM-associated gene expression in fibroblasts

2021 ◽  
Author(s):  
Brijesh Kumar Verma ◽  
Aritra Chatterjee ◽  
Paturu Kondaiah ◽  
Namrata Gundiah
Keyword(s):  
Gene Expression ◽  
Gelatin Zymography ◽  
Confocal Imaging ◽  
Substrate Stiffness ◽  
Specific Substrate ◽  
Tgf Beta ◽  
Cell Nuclei ◽  
Compliant Substrates ◽  
Collagen Iii ◽  
Activated State

Biomaterials, like polydimethylsiloxane (PDMS), are soft, biocompatible, and tuneable, which makes them useful to delineate specific substrate factors that regulate the complex landscape of cell-substrate interactions. We used a commercial formulation of PDMS to fabricate substrates with moduli 40 kPa, 300 kPa, and 1.5 MPa, and cultured HMF3S fibroblasts on them. Gene expression analysis was performed by RT-PCR and Western blotting. Cellular and nuclear morphologies were analyzed using confocal imaging, and MMP-2 and MMP-9 activities were determined with gelatin zymography. Results, comparing mechanotransduction on PDMS substrates with control petridishes, show that substrate stiffness modulates cell morphologies and proliferations. Cell nuclei were rounded on compliant substrates and correlated with increased tubulin expression. Proliferations were higher on stiffer substrates with cell cycle arrest on softer substrates. Integrin alpha5 expression decreased on lower stiffness substrates, and correlated with inefficient TGF-beta; activation. Changes to the activated state of the fibroblast on higher stiffness substrates were linked to altered TGF-beta; secretion. Collagen I, collagen III, and MMP-2 expression levels were lower on compliant PDMS substrates as compared to stiffer ones; there was little MMP-9 activity on substrates. These results demonstrate critical feedback mechanisms between substrate stiffness and ECM regulation by fibroblasts which is highly relevant in diseases like tissue fibrosis.

scholarly journals Tissue pressure and cell traction compensate to drive robust aggregate spreading

2020 ◽  
Author(s):  
M. S. Yousafzai ◽  
V. Yadav ◽  
S. Amiri ◽  
M.F. Staddon ◽  
A. P. Tabatabai ◽  
...  
Keyword(s):  
Surface Tension ◽  
Cell Aggregates ◽  
Liquid Droplets ◽  
Compensatory Mechanisms ◽  
Tissue Pressure ◽  
Comparable Rate ◽  
Compliant Substrates ◽  
Interfacial Energies ◽  
Active Liquid ◽  
Context Specific

AbstractIn liquid droplets, the balance of interfacial energies and substrate elasticity determines the shape of the droplet and the dynamics of wetting. In living cells, interfacial energies are not constant, but adapt to the mechanics of their environment. As a result, the forces driving the dynamics of wetting for cells and tissues are unclear and may be context specific. In this work, using a combination of experimental measurements and modeling, we show the surface tension of cell aggregates, as models of active liquid droplets, depends upon the size of the aggregate and the magnitude of applied load, which alters the wetting dynamics. Upon wetting rigid substrates, traction stresses are elevated at the boundary, and tension drives forward motion. By contrast, upon wetting compliant substrates, traction forces are attenuated, yet wetting occurs at a comparable rate. In this case, capillary forces at the contact line are elevated and aggregate surface tension contributes to strong outward, pressure-driven cellular flows. Thus, cell aggregates adapt to the mechanics of their environments, using pressure and traction as compensatory mechanisms to drive robust wetting.

Modeling of contact-induced radial cracking in ceramic bilayer coatings on compliant substrates

2003 ◽  
Vol 18 (5) ◽  
pp. 1275-1283 ◽  
Author(s):  
Chun-Hway Hsueh ◽  
Pedro Miranda
Keyword(s):  
Flexural Rigidity ◽  
Ceramic Coatings ◽  
Analytical Expression ◽  
Bilayer Coating ◽  
Compliant Substrates ◽  
Dental Crowns ◽  
Plates On Elastic Foundation ◽  
Radial Cracks ◽  
Good Agreement ◽  
Bilayer Coatings

Contact-induced radial cracking in ceramic coatings on compliant substrates was analyzed recently. Radial cracks initiate at the coating/substrate interface beneath the contact where maximum flexural tension occurs, and an analytical expression for the onset of radial cracking in monolayer coatings was formulated on the basis of the classical solution for flexing plates on elastic foundation. In the present study, the analytical expression was derived for the case of ceramic bilayer coatings on compliant substrates, which have significant applications in the structure of dental crowns. It was found that the analytical solution for bilayer-coating/substrate systems can be obtained from that of monolayer-coating/substrate systems by replacing the neutral surface position and the flexural rigidity of monolayer coating with those of bilayer coating. The predicted critical loads for initiating radial cracking were found to be in good agreement with existing measurements and finite element results for glass/alumina, glass/glass-ceramic, and glass/Y2O3-stabilized ZrO2polycrystal bilayers on polycarbonate substrates. Limitations of the present analysis are discussed.

scholarly journals Cell-Cell Mechanical Communication through Compliant Substrates

2008 ◽  
Vol 95 (12) ◽  
pp. 6044-6051 ◽  
Author(s):  
Cynthia A. Reinhart-King ◽  
Micah Dembo ◽  
Daniel A. Hammer
Keyword(s):  
Compliant Substrates ◽  
Cell Cell

scholarly journals Wetting transitions in droplet drying on soft materials

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Julia Gerber ◽  
Tobias Lendenmann ◽  
Hadi Eghlidi ◽  
Thomas M. Schutzius ◽  
Dimos Poulikakos
Keyword(s):  
Contact Line ◽  
Traction Force ◽  
Soft Materials ◽  
Wetting Transition ◽  
Surface Design ◽  
Complex Processes ◽  
Compliant Substrates ◽  
Rate Dependent ◽  
Liquid Removal ◽  
Droplet Drying

Abstract Droplet interactions with compliant materials are familiar, but surprisingly complex processes of importance to the manufacturing, chemical, and garment industries. Despite progress—previous research indicates that mesoscopic substrate deformations can enhance droplet drying or slow down spreading dynamics—our understanding of how the intertwined effects of transient wetting phenomena and substrate deformation affect drying remains incomplete. Here we show that above a critical receding contact line speed during drying, a previously not observed wetting transition occurs. We employ 4D confocal reference-free traction force microscopy (cTFM) to quantify the transient displacement and stress fields with the needed resolution, revealing high and asymmetric local substrate deformations leading to contact line pinning, illustrating a rate-dependent wettability on viscoelastic solids. Our study has significance for understanding the liquid removal mechanism on compliant substrates and for the associated surface design considerations. The developed methodology paves the way to study complex dynamic compliant substrate phenomena.

Structural-spectroscopic study of epitaxial GaAs layers grown on compliant substrates based on a superstructural layer and protoporous silicon

2021 ◽  
Vol 537 ◽  
pp. 147985
Author(s):  
P.V. Seredin ◽  
D.L. Goloshchapov ◽  
I.N. Arsentyev ◽  
D.N. Nikolayev ◽  
N.A. Pikhtin ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Epitaxial Gaas ◽  
Compliant Substrates

Facile Fabrication of Ordered Crystalline-Semiconductor Microstructures on Compliant Substrates

2013 ◽  
Vol 24 (12) ◽  
pp. 1730-1737 ◽  
Author(s):  
Francesca Cavallo ◽  
Kevin T. Turner ◽  
Max G. Lagally
Keyword(s):  
Compliant Substrates ◽  
Crystalline Semiconductor ◽  
Facile Fabrication
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