Poisson's ratio of collagen fibrils measured by small angle X-ray scattering of strained bovine pericardium

Wells, Hannah C.; Sizeland, Katie H.; Kayed, Hanan R.; Kirby, Nigel; Hawley, Adrian; Mudie, Stephen; Haverkamp, Richard G.

doi:10.1063/1.4906325

Cited by 37 publications

(44 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ANOVA testing was performed using MATLAB function anovan. Cells and collagen were assumed to be incompressible at the length scale of AFM indentation ( ) 51 52 , however experiments performed on both bulk collagen 75 and single ECM fibrils 76 demonstrate ν col. > 0.5, presumably due to water flux, thus some systematic errors may arise from this choice. AFM force-indentation curves are fit assuming a sphero-conical tip geometry.…”

Section: Methodsmentioning

confidence: 99%

Correlating confocal microscopy and atomic force indentation reveals metastatic cancer cells stiffen during invasion into collagen I matrices

Staunton

Doss

Lindsay

et al. 2016

Sci Rep

135

102

View full text Add to dashboard Cite

Mechanical interactions between cells and their microenvironment dictate cell phenotype and behavior, calling for cell mechanics measurements in three-dimensional (3D) extracellular matrices (ECM). Here we describe a novel technique for quantitative mechanical characterization of soft, heterogeneous samples in 3D. The technique is based on the integration of atomic force microscopy (AFM) based deep indentation, confocal fluorescence microscopy, finite element (FE) simulations and analytical modeling. With this method, the force response of a cell embedded in 3D ECM can be decoupled from that of its surroundings, enabling quantitative determination of the elastic properties of both the cell and the matrix. We applied the technique to the quantification of the elastic properties of metastatic breast adenocarcinoma cells invading into collagen hydrogels. We found that actively invading and fully embedded cells are significantly stiffer than cells remaining on top of the collagen, a clear example of phenotypical change in response to the 3D environment. Treatment with Rho-associated protein kinase (ROCK) inhibitor significantly reduces this stiffening, indicating that actomyosin contractility plays a major role in the initial steps of metastatic invasion.

show abstract

Section: Methodsmentioning

confidence: 99%

Correlating confocal microscopy and atomic force indentation reveals metastatic cancer cells stiffen during invasion into collagen I matrices

Staunton

Doss

Lindsay

et al. 2016

Sci Rep

135

102

View full text Add to dashboard Cite

show abstract

“…The prominent peak appearing in the equatorial intensity distribution at q = 1.38 nm À1 is ascribed to the presence of triacylglycerols (TAGs), which are the major constituents of lipids. This peak is absent in the scattering patterns of pure collagen reported elsewhere [32]. The lipid molecules are composed of hydrocarbon chains, which are packed in a hexagonal lattice forming lamellar structures [29,33,34].…”

Section: Small Angle X-ray Scattering Of Collagen Fibresmentioning

confidence: 67%

High pressure Raman study of type‐I collagen

et al. 2018

View full text Add to dashboard Cite

The high pressure response of type-I collagen from bovine Achilles tendon is investigated with micro-Raman spectroscopy. Fluorinert™ and methanol-ethanol mixtures were used as pressure transmitting media (PTM) in a diamond anvil cell. The Raman spectrum of collagen is dominated by three bands centred at approximately 1450, 1660 and 2930 cm , attributed to C-H deformation, C=O stretching of the peptide bond (amide-I band) and C-H stretching modes respectively. Upon pressure increase, using Fluorinert™ as PTM, a shift towards higher frequencies of the C-H stretching and deformation peaks is observed. Contrary, the amide-I band peaks are shifted to lower frequencies with moderate pressure slopes. On the other hand, when using the alcohol mixture as PTM, the amide-I band exhibits more pronounced C=O bond softening, deduced from the shift to lower frequencies, suggesting a strengthening of the hydrogen bonds between glycine and proline residues of different collagen chains due to the presence of the polar alcohol molecules. Furthermore, some of the peaks exhibit abrupt changes in their pressure slopes at approximately 2 GPa, implying a variation in the compressibility of the collagen fibres. This could be attributed to a pitch change from 10/3 to 7/2, sliding of the tropocollagen molecules, twisting variation at the molecular level and/or elimination of the D-gaps induced by kink compression. All spectral changes are reversible upon pressure release, which indicates that denaturation has not taken place. Finally, a minor lipid phase contamination was detected in some sample spots. Its pressure response is also monitored.

show abstract

“…5B). Large Poisson's ratio in tension (~2) have been reported for individual fibrils (Wells et al, 2015), which is greater than the 360 isotropic limit of = 0.5. Anisotropy of the isolated fibril material might need to be incorporated in the future to further investigate the effect of Poisson's ratio in the interfibrillar load transfer.…”

Section: Finite Element Simulations Of the Helical Fibrilsmentioning

confidence: 88%

3D Microstructure of Tendon Collagen Fibrils using Serial Block-Face SEM and a Mechanical Model for Load Transfer

Peloquin

Natriello

et al. 2019

Preprint

View full text Add to dashboard Cite

Tendon's hierarchical structure allows for load transfer between its fibrillar elements at multiple length scales. Tendon microstructure is particularly 35 important, because it includes the cells and their surrounding collagen fibrils, where mechanical interactions can have potentially important physiological and pathological contributions. However, the three-dimensional microstructure and the mechanisms of load transfer in that length scale are not known. It has been postulated that interfibrillar matrix shear or direct load transfer via the 40 fusion/branching of small fibrils are responsible for load transfer, but the significance of these mechanisms is still unclear. Alternatively, the helical fibrils that occur at the microstructural scale in tendon may also mediate load transfer, however, these structures are not well studied due to the lack of a threedimensional visualization of tendon microstructure. In this study, we used serial 45 block-face scanning electron microscopy (SBF-SEM) to investigate the threedimensional microstructure of fibrils in rat tail tendon. We found that tendon fibrils have a complex architecture with many helically wrapped fibrils. We studied the mechanical implications of these helical structures using finite element modeling and found that frictional contact between helical fibrils can 50 induce load transfer even in the absence of matrix bonding or fibril fusion/branching. This study is significant in that it provides a three-dimensional view of the tendon microstructure and suggests friction between helically wrapped fibrils as a mechanism for load transfer, which is an important aspect of tendon biomechanics. [Word count 232/250] 55

show abstract

Poisson's ratio of collagen fibrils measured by small angle X-ray scattering of strained bovine pericardium

Cited by 37 publications

References 32 publications

Correlating confocal microscopy and atomic force indentation reveals metastatic cancer cells stiffen during invasion into collagen I matrices

Correlating confocal microscopy and atomic force indentation reveals metastatic cancer cells stiffen during invasion into collagen I matrices

High pressure Raman study of type‐I collagen

3D Microstructure of Tendon Collagen Fibrils using Serial Block-Face SEM and a Mechanical Model for Load Transfer

Contact Info

Product

Resources

About