scholarly journals Mechanical plasticity of the ECM directs invasive branching morphogenesis in human mammary gland organoids

2019 ◽  
Author(s):  
B. Buchmann ◽  
L.K. Meixner ◽  
P. Fernandez ◽  
F.P. Hutterer ◽  
M.K. Raich ◽  
...  
Keyword(s):  
Feedback Loop ◽  
Mechanical Response ◽  
Collective Motion ◽  
Branching Morphogenesis ◽  
Feedback Mechanism ◽  
Direct Organogenesis ◽  
Collagen Network ◽  
The Matrix ◽  
Tension Generation ◽  
Organizing Principles

Although branching morphogenesis is central for organogenesis in diverse organs, the underlying self-organizing principles have yet to be identified. Here, we show that invasive branching morphogenesis in human mammary organoids relies on an intricate tension-driven feedback mechanism, which is based on the nonlinear and plastic mechanical response of the surrounding collagen network. Specifically, we demonstrate that collective motion of cells within organoid branches generates tension that is strong enough to induce a plastic reorganization of the surrounding collagen network which results in the formation of mechanically stable collagen cages. Such matrix encasing in turn directs further tension generation, branch outgrowth and plastic deformation of the matrix. The identified mechanical feedback-loop sets a framework to understand how mechanical cues direct organogenesis.

scholarly journals Mechanical plasticity of collagen directs branch elongation in human mammary gland organoids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
B. Buchmann ◽  
L. K. Engelbrecht ◽  
P. Fernandez ◽  
F. P. Hutterer ◽  
M. K. Raich ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Developmental Process ◽  
Branching Morphogenesis ◽  
Collagen Network ◽  
Mechanical Tension ◽  
Structural Reorganization ◽  
Linear Response Regime ◽  
Human Mammary Gland ◽  
The Matrix ◽  
Tension Generation

AbstractEpithelial branch elongation is a central developmental process during branching morphogenesis in diverse organs. This fundamental growth process into large arborized epithelial networks is accompanied by structural reorganization of the surrounding extracellular matrix (ECM), well beyond its mechanical linear response regime. Here, we report that epithelial ductal elongation within human mammary organoid branches relies on the non-linear and plastic mechanical response of the surrounding collagen. Specifically, we demonstrate that collective back-and-forth motion of cells within the branches generates tension that is strong enough to induce a plastic reorganization of the surrounding collagen network which results in the formation of mechanically stable collagen cages. Such matrix encasing in turn directs further tension generation, branch outgrowth and plastic deformation of the matrix. The identified mechanical tension equilibrium sets a framework to understand how mechanical cues can direct ductal branch elongation.

Architectural changes of trabecular bone caused by the remodeling process

2005 ◽  
Vol 874 ◽  
Author(s):  
Richard Weinkamer ◽  
Markus A. Hartmann ◽  
Yves Brechet ◽  
Peter Fratzl
Keyword(s):  
Trabecular Bone ◽  
Feedback Loop ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Bone Volume ◽  
Bone Architecture ◽  
Mechanical Problem ◽  
Bone Volume Fraction ◽  
Obvious Effect ◽  
Trabecular Bone Architecture

AbstractUsing a stochastic lattice model we have studied the architectural changes of trabecular bone occurring while the structure is remodeled. Our model considers the mechanical feedback loop, which control the remodeling process. A fast algorithm was employed to solve approximately the mechanical problem. A general feature of the model is that a networklike structure emerges, which further coarsens while the bone volume fraction remains unchanged. Decreasing the mechanical response of the system by either lowering the external load or the internal mechano-sensitivity leads not only to a reduction of the bone volume fraction, but results in topological changes of the trabecular bone architecture, where the loss of horizontal trabeculae is the most obvious effect.

Modeling the Matrix of Articular Cartilage Using a Continuous Fiber Angular Distribution Predicts Many Observed Phenomena

2009 ◽  
Author(s):  
Gerard A. Ateshian ◽  
Vikram Rajan ◽  
Nadeen O. Chahine ◽  
Clare Canal Guterl ◽  
Clark T. Hung
Keyword(s):  
Angular Distribution ◽  
Mechanical Response ◽  
Strain Curve ◽  
Collagen Matrix ◽  
Compressive Properties ◽  
Continuous Fiber ◽  
Stress Strain Curve ◽  
Theoretical Frameworks ◽  
The Matrix ◽  
Discrete Fiber

A number of theoretical frameworks embodying the disparity between tensile and compressive properties of cartilage have been proposed, accounting for the collagen fibers implicitly [1,2] or explicitly [3–5]. These models generally propose discrete fiber families to describe the collagen matrix. They are able to capture the most salient features of the cartilage mechanical response, namely, the tension-compression nonlinearity of the stress-strain curve [6].

Flexural Behavior of a Layer-to-Layer Orthogonal Interlocked Three-Dimensional Textile Composite

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
D. Zhang ◽  
A. M. Waas ◽  
M. Pankow ◽  
C. F. Yen ◽  
S. Ghiorse
Keyword(s):  
Mechanical Response ◽  
Peak Load ◽  
Three Dimensional ◽  
Peak Stress ◽  
Surface Strain ◽  
Image Correlation ◽  
Flexural Behavior ◽  
Fe Model ◽  
Textile Composite ◽  
The Matrix

The flexural response of a three-dimensional (3D) layer-to-layer orthogonal interlocked textile composite has been investigated under quasi-static three-point bending. Fiber tow kinking on the compressive side of the flexed specimens has been found to be a strength limiting mechanism for both warp and weft panels. The digital image correlation (DIC) technique has been utilized to map the deformation and identify the matrix microcracking on the tensile side prior to the peak load in the warp direction loaded panels. It has been shown that the geometrical characteristics of textile reinforcement play a key role in the mechanical response of this class of material. A 3D local–global finite element (FE) model that reflects the textile architectures has been proposed to successfully capture the surface strain localizations in the predamage region. To analyze the kink banding event, the fiber tow is modeled as an inelastic degrading homogenized orthotropic solid in a state of plane stress based on Schapery Theory (ST). The predicted peak stress is in agreement with the tow kinking stress obtained from the 3D FE model.

The Role of Agarose Mechanical Response on the Matrix Synthesis of Nucleus Pulposus Cells: A Pilot Study

2009 ◽  
Author(s):  
Arzu Tasci ◽  
Ladina Ettinger ◽  
Stephen Ferguson ◽  
Philippe Büchler
Keyword(s):  
Cyclic Loading ◽  
Mechanical Response ◽  
Low Back ◽  
Limited Capacity ◽  
Nucleus Pulposus Cells ◽  
Matrix Synthesis ◽  
Biosynthetic Activity ◽  
The Matrix ◽  
Ivd Degeneration

Low back pain is the most common spinal disorder and its main cause is intervertebral disc (IVD) degeneration. IVD has a major role of withstanding loads generated in the spine during daily activities. However, it has a limited capacity for self-repair. Since it has an avascular structure, the pathways it uses for regeneration is quite complex and not yet well understood. The mechanical stimulation studies on the cell seeded constructs revealed that cells regulate their biosynthetic activity with cyclic loading [1,2]. The mechanical properties of the scaffold might play an important role in the transmission of mechanical signals to the embedded cells. The objective of this study is to investigate the effect of agarose concentration on the amount of extracellular matrix synthesis in IVD cell seeded constructs under static culture and cyclic loading conditions.

Elucidation of Microstructural Interactions Between Collagen and Non-Fibrillar Matrix in Soft Tissue Using a Coupled Fiber-Matrix Model

2012 ◽  
Author(s):  
Lijuan Zhang ◽  
Spencer P. Lake ◽  
Victor K. Lai ◽  
Victor H. Barocas ◽  
Mark S. Shephard
Keyword(s):  
Soft Tissues ◽  
Mechanical Response ◽  
Tensile Load ◽  
Matrix Composites ◽  
Collagen Network ◽  
Fiber Network ◽  
Matrix Modeling ◽  
Microscale Model ◽  
Fiber Matrix

The mechanical properties of soft connective tissues are governed by their collagen fiber network and surrounding non-fibrillar matrix (e.g., proteoglycans, cells, elastin, etc.). In order to understand how healthy tissues function, and how properties change in injury and disease, it is necessary to quantify the mechanical response of both the collagen network and the non-fibrillar matrix (NFM), as well as the nature of the interaction between these tissue constituents. Using collagen-agarose co-gels as a simple experimental tissue analog system, we have demonstrated how NFM contributes to the mechanical and organizational properties of soft tissues in indentation and tension [1–2]. Furthermore, we used a network-based microscale model to examine how specific NFM properties alter the response of fiber-matrix composites under load [3]. This model fit our experimental data well and provided insight into the role of NFM in tensile mechanics. Since it was constructed according to the conventional approach of superposition of the two constituents (collagen network and NFM), however, the model could not specifically examine local interactions between collagen fibers and the surrounding NFM, which could be critical in assessing tissue damage or cell-matrix interactions. Therefore, we developed and evaluated a fiber-matrix modeling scheme to characterize the microstructural interactions between tissue constituents, as well as to quantify the role of individual tissue components in the behavior of soft tissues under tensile load. For validation, the new model (‘coupled’) was compared to our previous model (‘parallel’) and to experimental co-gel data.

Nano-additive reinforcement of mixture epoxy syntactic foams

2019 ◽  
Vol 33 (12) ◽  
pp. 1674-1691 ◽  
Author(s):  
Kerrick R Dando ◽  
David R Salem
Keyword(s):  
Impact Analysis ◽  
Mechanical Response ◽  
Analysis Data ◽  
Halloysite Nanotubes ◽  
Peak Force ◽  
Syntactic Foams ◽  
Response Properties ◽  
Weight Percentage ◽  
Time To Peak ◽  
The Matrix

Carbon nanofibers (CNFs) and halloysite nanotubes (HNTs) were incorporated in syntactic foams containing a 90% by volume homogeneous mixture of (20/80 wt%) glass/thermoplastic microballoons to enhance the mechanical and impact response properties. Tensile, compressive, and impact tests were employed to comparatively characterize the effect of nano-additive reinforcement on mechanical response properties. Compressive strength and modulus enhancements as large as 39% and 18%, respectively, were achieved with a 0.125 wt% addition of CNF and increases of 61% and 7%, respectively, were achieved with a 0.125 wt% addition of HNT. Tensile strength and modulus enhancements as large as 107% and 68%, respectively, were achieved with a 0.125 wt% addition of CNF and increases of 104% and 70%, respectively, were achieved with a 0.125 wt% addition of HNT. Impact analysis data were used to show that measured peak force increased and build-up time to peak force decreased with increasing CNF or HNT weight percentage due to stiffening of the matrix. The smallest increase observed in peak force was 20% for a 0.125 wt% addition of CNF and 17% for a 0.125 wt% addition of HNT.

scholarly journals Finite Element Simulation of the Thermo-mechanical Response of Graphene Reinforced Nanocomposites

2018 ◽  
Vol 188 ◽  
pp. 01016
Author(s):  
Androniki S. Tsiamaki ◽  
Nick K. Anifantis
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Matrix Material ◽  
Continuum Theory ◽  
Element Model ◽  
Multilayer Graphene ◽  
Temperature Changes ◽  
The Matrix

The research for new materials that can withstand extreme temperatures and present good mechanical behavior is of great importance. The interest is highly focused on the utilization of composites reinforced by nanomaterials. To cope with this goal the present work studies the mechanical response of graphene reinforced nanocomposite structures subjected to temperature changes. A computational finite element model has been developed that accounts for both the reinforcement and the matrix material phases. The model developed is based on both the continuum theory and the molecular mechanics theory, for the simulation of the three different material phases of the composite, respectively, i.e. the matrix, the intermediate transition phase and the reinforcement. Considering this model, the mechanical response of an appropriate representative volume element of the nanocomposite is simulated under various temperature changes. The study involves different types of reinforcement composed from either monolayer or multilayer graphene sheets. Apart from the investigation of the behavior of a nanocomposite with each particular type of the reinforcement, comparisons are also presented between them in order to reveal optimized material combinations. The principal parameters taken into consideration, which contribute also to the mechanical behavior of the nanocomposite, are its size, the sheet multiplicity as well as the volume fraction.

scholarly journals 685 Study of functional fibrillary collagen network from the cell level to the matrix maturation

2016 ◽  
Vol 136 (5) ◽  
pp. S121
Author(s):  
D. Rival ◽  
S. Pain ◽  
M. Chavan ◽  
S. Cadau ◽  
D. Gauché ◽  
...  
Keyword(s):  
Collagen Network ◽  
Cell Level ◽  
The Matrix ◽  
Matrix Maturation

Progress in the Development of a Mechanical Properties Microprobe

MRS Bulletin ◽  
1986 ◽  
Vol 11 (5) ◽  
pp. 15-21 ◽  
Author(s):  
W. C. Oliver
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Quantitative Information ◽  
General Term ◽  
Strength Properties ◽  
Physical Measurements ◽  
Wide Range ◽  
The Matrix ◽  
Recent Developments ◽  
Skilled Practitioner

A mechanical properties microprobe is an exciting concept. A system with the ability to evaluate the mechanical response of a sample with submicron spacial resolution would have an extremely wide range of applications. Recent developments in hardware and understanding have placed this goal within our grasp.In 1971, J.J.Gilman wrote the following in his article, “Hardness—A Strength Microprobe”:“Hardness measurements are at once among the most maligned and the most magnificent of physical measurements. Maligned because they are often misinterpreted by the uninitiated, and magnificent because they are so efficient in generating information for the skilled practitioner. They can quickly yield quantitative information about the elastic, anelastic, plastic, viscous, and fracture properties of a great variety of both isotropic and anisotropic solids. The tools that are used are simple and the sample sizes that are needed are typically small, sometimes submicroscopic. This makes it unnecessary to have large specimens in order to measure strength properties and makes it possible to measure the properties of various microscopic particles within the matrix phase of a polyphase metal, mineral, or ceramic material. This is why hardness may be considered to be a strength microprobe.”These statements are worth repeating for two reasons. First, they point out the largely untapped potential for microin-dentation tests to improve our understanding of the mechanical properties of materials. Second, it is the first mention of hardness tests in the context of a strength microprobe. In this article the more general term of microindentation tests will be used, since hardness is only one of many properties that can be measured with such tests. In addition, the term mechanical properties microprobe (MPM) will be used rather than strength microprobe-again, to note the wide variety of properties that can be measured.

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