Determining the mechanical properties of human corneal basement membranes with atomic force microscopy

Liliensiek, Sara J.; Nealey, Paul F.; Murphy, Christopher J.

doi:10.1016/j.jsb.2009.03.012

Cited by 187 publications

(160 citation statements)

References 50 publications

Supporting

Mentioning

141

Contrasting

Unclassified

Order By: Relevance

“…The physiological range of cell substrate stiffness in the body varies from ϳ1 kPa in the brain (18), ϳ5 kPa in the alveolar wall (45), and ϳ10 kPa in the corneal basement membrane (27) to ϳ30 kPa in precalcified bone (12,13,16). These values depend on tissue source and species, and in a given tissue, they can vary with location (12,13,59).…”

Section: C150 Substrate Stiffening and Endothelial Barrier Integritymentioning

confidence: 99%

Substrate stiffening promotes endothelial monolayer disruption through enhanced physical forces

Krishnan¹,

Klumpers²,

Park³

et al. 2011

American Journal of Physiology-Cell Physiology

215

237

View full text Add to dashboard Cite

GP. Substrate stiffening promotes endothelial monolayer disruption through enhanced physical forces. Am J Physiol Cell Physiol 300: C146 -C154, 2011. First published September 22, 2010; doi:10.1152/ajpcell.00195.2010.-A hallmark of many, sometimes life-threatening, inflammatory diseases and disorders is vascular leakage. The extent and severity of vascular leakage is broadly mediated by the integrity of the endothelial cell (EC) monolayer, which is in turn governed by three major interactions: cell-cell and cell-substrate contacts, soluble mediators, and biomechanical forces. A potentially critical but essentially uninvestigated component mediating these interactions is the stiffness of the substrate to which the endothelial monolayer is adherent. Accordingly, we investigated the extent to which substrate stiffening influences endothelial monolayer disruption and the role of cell-cell and cell-substrate contacts, soluble mediators, and physical forces in that process. Traction force microscopy showed that forces between cell and cell and between cell and substrate were greater on stiffer substrates. On stiffer substrates, these forces were substantially enhanced by a hyperpermeability stimulus (thrombin, 1 U/ml), and gaps formed between cells. On softer substrates, by contrast, these forces were increased far less by thrombin, and gaps did not form between cells. This stiffness-dependent force enhancement was associated with increased Rho kinase activity, whereas inhibition of Rho kinase attenuated baseline forces and lessened thrombin-induced inter-EC gap formation. Our findings demonstrate a central role of physical forces in EC gap formation and highlight a novel physiological mechanism. Integrity of the endothelial monolayer is governed by its physical microenvironment, which in normal circumstances is compliant but during pathology becomes stiffer. contraction; human umbilical vein endothelial cells; permeability; traction force; cell-cell contact; cell-substrate contact; substrate stiffness; Rho kinase; vascular endothelial cadherin; thrombin THE OVERALL INTEGRITY and barrier properties of the endothelial cell (EC) monolayer are governed by three main categories of inputs: cell-cell and cell-substrate contacts, soluble mediators (e.g., thrombin, histamine, spingosphine 1-phosphate, and nitric oxide), and biomechanics (e.g., innate monolayer forces, shear forces, and stretch) (33). In vivo, these inputs are integrated by the EC monolayer to regulate its overall integrity and responses to inflammatory stimuli. Characterizing these inputs and their interrelationships is thus of central importance for understanding vascular biology and inflammation as a whole.A potentially critical, but entirely ignored, component of the EC environment that may influence the aforementioned inputs and their interactions is stiffness of the substrate to which the EC monolayer is adherent. This substrate stiffness varies greatly among diverse physiological settings (12,13,32,59), is enhanced with aging (21, 40), and is exacerbate...

show abstract

Section: C150 Substrate Stiffening and Endothelial Barrier Integritymentioning

confidence: 99%

Substrate stiffening promotes endothelial monolayer disruption through enhanced physical forces

Krishnan¹,

Klumpers²,

Park³

et al. 2011

American Journal of Physiology-Cell Physiology

215

237

View full text Add to dashboard Cite

show abstract

“…Unfortunately, reported values of YM for a given tissue can span several orders of magnitude. The human cornea is a good example, with reported modulus values ranging from 2.9 kPa 36 to 19 MPa 37 when measured by atomic force microscopy (AFM) 38 tensile stretching, 39,40 tonometry, [41][42][43] or inflation/bulge testing, 36,37,[44][45][46][47] This wide variation in reported YM values is not limited to the cornea. Part of the variation in reported YM values stems from variation in controllable experimental variables.…”

Section: Introductionmentioning

confidence: 99%

Indentation Versus Tensile Measurements of Young's Modulus for Soft Biological Tissues

McKee

Russell

Murphy³

2011

Tissue Engineering Part B: Reviews

Self Cite

579

402

View full text Add to dashboard Cite

“…These results are, however, in decent conformity with the results of other respective works carried out on characterizing the human cells. 16,44 For such a mechanical/electrical engineering framework presented here, there are many interesting and promising applications such as biological engineering and medicine. For instance, this could revolutionize the domain of surgery by opening a new vision to the microsurgery demanding high stability, robustness, and precision.…”

Section: Resultsmentioning

confidence: 99%

Integrated automated nanomanipulation and real-time cellular surface imaging for mechanical properties characterization

Eslami

Zareian

Jalili

2012

Review of Scientific Instruments

View full text Add to dashboard Cite

Surface microscopy of individual biological cells is essential for determining the patterns of cell migration to study the tumor formation or metastasis. This paper presents a correlated and effective theoretical and experimental technique to automatically address the biophysical and mechanical properties and acquire live images of biological cells which are of interest in studying cancer. In the theoretical part, a distributed-parameters model as the comprehensive representation of the microcantilever is presented along with a model of the contact force as a function of the indentation depth and mechanical properties of the biological sample. Analysis of the transfer function of the whole system in the frequency domain is carried out to characterize the stiffness and damping coefficients of the sample. In the experimental section, unlike the conventional atomic force microscope techniques basically using the laser for determining the deflection of microcantilever's tip, a piezoresistive microcantilever serving as a force sensor is implemented to produce the appropriate voltage and measure the deflection of the microcantilever. A micromanipulator robotic system is integrated with the MATLAB(®) and programmed in such a way to automatically control the microcantilever mounted on the tip of the micromanipulator to achieve the topography of biological samples including the human corneal cells. For this purpose, the human primary corneal fibroblasts are extracted and adhered on a sterilized culture dish and prepared to attain their topographical image. The proposed methodology herein allows an approach to obtain 2D quality images of cells being comparatively cost effective and extendable to obtain 3D images of individual cells. The characterized mechanical properties of the human corneal cell are furthermore established by comparing and validating the phase shift of the theoretical and experimental results of the frequency response.

show abstract

Determining the mechanical properties of human corneal basement membranes with atomic force microscopy

Cited by 187 publications

References 50 publications

Substrate stiffening promotes endothelial monolayer disruption through enhanced physical forces

Substrate stiffening promotes endothelial monolayer disruption through enhanced physical forces

Indentation Versus Tensile Measurements of Young's Modulus for Soft Biological Tissues

Integrated automated nanomanipulation and real-time cellular surface imaging for mechanical properties characterization

Contact Info

Product

Resources

About