scholarly journals Combinatorial screen of dynamic mechanical stimuli for predictive control of MSC mechano-responsiveness

2021 ◽  
Vol 7 (19) ◽  
pp. eabe7204
Author(s):  
Haijiao Liu ◽  
Jenna F. Usprech ◽  
Prabu Karthick Parameshwar ◽  
Yu Sun ◽  
Craig A. Simmons
Keyword(s):  
Mechanical Stimulation ◽  
Interactive Effect ◽  
Three Dimensional ◽  
Mechanical Stimuli ◽  
Dynamic Mechanical ◽  
Response Data ◽  
Deformable Membrane ◽  
Matrix Production ◽  
Strain Magnitude ◽  
The Individual

Mechanobiological-based control of mesenchymal stromal cells (MSCs) to facilitate engineering and regeneration of load-bearing tissues requires systematic investigations of specific dynamic mechanical stimulation protocols. Using deformable membrane microdevice arrays paired with combinatorial experimental design and modeling, we probed the individual and integrative effects of mechanical stimulation parameters (strain magnitude, rate at which strain is changed, and duty period) on myofibrogenesis and matrix production of MSCs in three-dimensional hydrogels. These functions were found to be dominantly influenced by a previously unidentified, higher-order interactive effect between strain magnitude and duty period. Empirical models based on our combinatorial cue-response data predicted an optimal loading regime in which strain magnitude and duty period were increased synchronously over time, which was validated to most effectively promote MSC matrix production. These findings inform the design of loading regimes for MSC-based engineered tissues and validate a broadly applicable approach to probe multifactorial regulating effects of mechanobiological cues.

scholarly journals Combinatorial Screen of Dynamic Mechanical Stimuli for Predictive Control of MSC Mechano-Responsiveness

2020 ◽  
Author(s):  
Haijiao Liu ◽  
Jenna F. Usprech ◽  
Prabu Karthick Parameshwar ◽  
Yu Sun ◽  
Craig A. Simmons
Keyword(s):  
Predictive Control ◽  
Mechanical Stimulation ◽  
Interactive Effect ◽  
Mechanical Stimuli ◽  
Dynamic Mechanical ◽  
Response Data ◽  
Stimulation Parameters ◽  
Deformable Membrane ◽  
Matrix Production ◽  
The Individual

AbstractMechanobiological-based control of mesenchymal stromal cells (MSCs) to aid in the engineering and regeneration of load-bearing tissues requires systematic investigations of specific dynamic mechanical stimulation protocols. Using deformable membrane microdevice arrays paired with combinatorial experimental design and modeling, we systematically probed the individual and integrative effects of mechanical stimulation parameters (strain magnitude (STRAIN), rate at which strain is changed (RATE) and duty period (DUTY)) on myofibrogenesis and matrix production of MSCs in 3D hydrogels. These functions were found to be dominantly influenced by a novel and higher-order interactive effect between STRAIN and DUTY. Empirical models based on our combinatorial cue-response data predicted an optimal loading regime in which STRAIN and DUTY were increased synchronously over time, which was validated to most effectively promote MSC matrix production. These findings inform the design of loading regimes for MSC-based engineered tissues and validate a broadly applicable approach to probe multifactorial regulating effects of microenvironmental and mechanobiological cues.

scholarly journals Design, Implementation, and Validation of a Piezoelectric Device to Study the Effects of Dynamic Mechanical Stimulation on Cell Proliferation, Migration and Morphology

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2155 ◽  
Author(s):  
Dahiana Mojena-Medina ◽  
Marina Martínez-Hernández ◽  
Miguel de la Fuente ◽  
Guadalupe García-Isla ◽  
Julio Posada ◽  
...  
Keyword(s):  
Mechanical Stimulation ◽  
Cell Monolayer ◽  
Mechanical Stimuli ◽  
Mechanical Parameters ◽  
Dynamic Stimuli ◽  
New Device ◽  
Dynamic Mechanical ◽  
Cell Functions ◽  
Biochemical Signals

Cell functions and behavior are regulated not only by soluble (biochemical) signals but also by biophysical and mechanical cues within the cells’ microenvironment. Thanks to the dynamical and complex cell machinery, cells are genuine and effective mechanotransducers translating mechanical stimuli into biochemical signals, which eventually alter multiple aspects of their own homeostasis. Given the dominant and classic biochemical-based views to explain biological processes, it could be challenging to elucidate the key role that mechanical parameters such as vibration, frequency, and force play in biology. Gaining a better understanding of how mechanical stimuli (and their mechanical parameters associated) affect biological outcomes relies partially on the availability of experimental tools that may allow researchers to alter mechanically the cell’s microenvironment and observe cell responses. Here, we introduce a new device to study in vitro responses of cells to dynamic mechanical stimulation using a piezoelectric membrane. Using this device, we can flexibly change the parameters of the dynamic mechanical stimulation (frequency, amplitude, and duration of the stimuli), which increases the possibility to study the cell behavior under different mechanical excitations. We report on the design and implementation of such device and the characterization of its dynamic mechanical properties. By using this device, we have performed a preliminary study on the effect of dynamic mechanical stimulation in a cell monolayer of an epidermal cell line (HaCaT) studying the effects of 1 Hz and 80 Hz excitation frequencies (in the dynamic stimuli) on HaCaT cell migration, proliferation, and morphology. Our preliminary results indicate that the response of HaCaT is dependent on the frequency of stimulation. The device is economic, easily replicated in other laboratories and can support research for a better understanding of mechanisms mediating cellular mechanotransduction.

scholarly journals A Role for Acid-sensing Ion Channel 3, but Not Acid-sensing Ion Channel 2, in Sensing Dynamic Mechanical Stimuli

2010 ◽  
Vol 113 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Jasenka Borzan ◽  
Chengshui Zhao ◽  
Richard A. Meyer ◽  
Srinivasa N. Raja
Keyword(s):  
Ion Channel ◽  
Nerve Injury ◽  
Mechanical Stimulation ◽  
Knockout Mice ◽  
Spinal Nerve ◽  
Spinal Nerve Ligation ◽  
Mechanical Stimuli ◽  
Baseline Sensitivity ◽  
Male And Female ◽  
Dynamic Mechanical

Background Acid-sensing ion channels 2 and 3 (ASIC2 and ASIC3, respectively) have been implicated as putative mechanotransducers. Because mechanical hyperalgesia is a prominent consequence of nerve injury, we tested whether male and female ASIC2 or ASIC3 knockout mice have altered responses to mechanical and heat stimuli at baseline and during the 5 weeks after spinal nerve ligation. Methods Age-matched, adult male and female ASIC2 knockout (n=21) and wild-type (WT; n=24) mice or ASIC3 knockout (n=20) and WT (n=19) mice were tested for sensitivity to natural stimuli before and after spinal nerve ligation surgery. All animals were first tested for baseline sensitivity to mechanical and heat stimuli and in a novel dynamic mechanical stimulation test. The same testing procedures were then repeated weekly after spinal nerve injury. Results Compared with their respective WT counterparts, ASIC2 and ASIC3 knockout mice had normal baseline sensitivity to standard mechanical and heat stimuli. However, when exposed to a novel stroking stimulus to test sensitivity to dynamic mechanical stimulation, ASIC3 knockout mice were significantly more sensitive than were WT mice. After spinal nerve ligation, ASIC2 and ASIC3 knockout mice developed mechanical and heat hyperalgesia comparable with that of their respective WT controls. In addition, in both experiments, female mice were more sensitive than male mice to heat at baseline and after the nerve injury. Conclusions We conclude that ASIC2 and ASIC3 channels are not directly involved in the development or maintenance of neuropathic pain after spinal nerve ligation. However, the ASIC3 channel significantly modulates the sensing of dynamic mechanical stimuli in physiologic condition.

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

Phonetic iconicity in the evaluative morphology of a sample of Indo-European, Niger-Congo and Austronesian languages

2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann
Keyword(s):  
Three Dimensional ◽  
Sound Symbolism ◽  
Three Dimensional Model ◽  
Austronesian Languages ◽  
Place Of Articulation ◽  
European Languages ◽  
Phonetic Symbolism ◽  
The Individual ◽  
Core Vocabulary

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.

scholarly journals A Novel Bioreactor for the Mechanical Stimulation of Clinically Relevant Scaffolds for Muscle Tissue Engineering Purposes

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 474
Author(s):  
Silvia Todros ◽  
Silvia Spadoni ◽  
Edoardo Maghin ◽  
Martina Piccoli ◽  
Piero G. Pavan
Keyword(s):  
Mechanical Stimulation ◽  
Strain Range ◽  
Tensile Tests ◽  
Muscular Tissue ◽  
Fe Model ◽  
Mechanical Stimuli ◽  
Physiological Strain ◽  
Cellular Alignment ◽  
Stimulation Of

Muscular tissue regeneration may be enhanced in vitro by means of mechanical stimulation, inducing cellular alignment and the growth of functional fibers. In this work, a novel bioreactor is designed for the radial stimulation of porcine-derived diaphragmatic scaffolds aiming at the development of clinically relevant tissue patches. A Finite Element (FE) model of the bioreactor membrane is developed, considering two different methods for gripping muscular tissue patch during the stimulation, i.e., suturing and clamping with pliers. Tensile tests are carried out on fresh and decellularized samples of porcine diaphragmatic tissue, and a fiber-reinforced hyperelastic constitutive model is assumed to describe the mechanical behavior of tissue patches. Numerical analyses are carried out by applying pressure to the bioreactor membrane and evaluating tissue strain during the stimulation phase. The bioreactor designed in this work allows one to mechanically stimulate tissue patches in a radial direction by uniformly applying up to 30% strain. This can be achieved by adopting pliers for tissue clamping. Contrarily, the use of sutures is not advisable, since high strain levels are reached in suturing points, exceeding the physiological strain range and possibly leading to tissue laceration. FE analysis allows the optimization of the bioreactor configuration in order to ensure an efficient transduction of mechanical stimuli while preventing tissue damage.

scholarly journals Modelling Polycrystalline Materials: An Overview of Three-Dimensional Grain-Scale Mechanical Models

2013 ◽  
Vol 05 (01) ◽  
pp. 1350002 ◽  
Author(s):  
I. Benedetti ◽  
F. Barbe
Keyword(s):  
Three Dimensional ◽  
Constitutive Modelling ◽  
Polycrystalline Materials ◽  
High Fidelity ◽  
Computational Capability ◽  
Mechanical Models ◽  
Three Dimensional Models ◽  
The Individual ◽  
Individual Grains ◽  
Micro Structures

A survey of recent contributions on three-dimensional grain-scale mechanical modelling of polycrystalline materials is given in this work. The analysis of material micro-structures requires the generation of reliable micro-morphologies and affordable computational meshes as well as the description of the mechanical behavior of the elementary constituents and their interactions. The polycrystalline microstructure is characterized by the topology, morphology and crystallographic orientations of the individual grains and by the grain interfaces and microstructural defects, within the bulk grains and at the inter-granular interfaces. Their analysis has been until recently restricted to two-dimensional cases, due to high computational requirements. In the last decade, however, the wider affordability of increased computational capability has promoted the development of fully three-dimensional models. In this work, different aspects involved in the grain-scale analysis of polycrystalline materials are considered. Different techniques for generating artificial micro-structures, ranging from highly idealized to experimentally based high-fidelity representations, are briefly reviewed. Structured and unstructured meshes are discussed. The main strategies for constitutive modelling of individual bulk grains and inter-granular interfaces are introduced. Some attention has also been devoted to three-dimensional multiscale approaches and some established and emerging applications have been discussed.

Research on Generation Rules of Chest Width Point Curve Based on 3D Female Mannequin

2013 ◽  
Vol 796 ◽  
pp. 513-518
Author(s):  
Rong Jin ◽  
Bing Fei Gu ◽  
Guo Lian Liu
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Upper Body ◽  
Secondary Development ◽  
Linear Regression Method ◽  
Point Cloud Data ◽  
Body Type ◽  
Cloud Data ◽  
Engineering Software ◽  
The Individual

In this paper 110 female undergraduates in Soochow University are measured by using 3D non-contact measurement system and manual measurement. 3D point cloud data of human body is taken as research objects by using anti-engineering software, and secondary development of point cloud data is done on the basis of optimizing point cloud data. In accordance with the definition of the human chest width points and other feature points, and in the operability of the three-dimensional point cloud data, the width, thickness, and length dimensions of the curve through the chest width point are measured. Classification of body type is done by choosing the ratio values as classification index which is the ratio between thickness and width of the curve. The generation rules of the chest curve are determined for each type by using linear regression method. Human arm model could be established by the computer automatically. Thereby the individual model of the female upper body mannequin modeling can be improved effectively.

A Numerically Efficient Method for Analysis of Very Large Articulated Floating Structures

1998 ◽  
Vol 42 (03) ◽  
pp. 174-186
Author(s):  
C. J. Garrison
Keyword(s):  
Hydrodynamic Interaction ◽  
Near Field ◽  
Three Dimensional ◽  
Computational Effort ◽  
Floating Structure ◽  
Complete Structure ◽  
Field Interaction ◽  
Floating Structures ◽  
Computing Effort ◽  
The Individual

A method is presented for evaluation of the motion of long structures composed of interconnected barges, or modules, of arbitrary shape. Such structures are being proposed in the construction of offshore airports or other large offshore floating structures. It is known that the evaluation of the motion of jointed or otherwise interconnected modules which make up a long floating structure may be evaluated by three dimensional radiation/diffraction analysis. However, the computing effort increases rapidly as the complexity of the geometric shape of the individual modules and the total number of modules increases. This paper describes an approximate method which drastically reduces the computational effort without major effects on accuracy. The method relies on accounting for hydrodynamic interaction effects between only adjacent modules within the structure rather than between all of the modules since the near-field interaction is by far the more important. This approximation reduces the computational effort to that of solving the two-module problem regardless of the total number of modules in the complete structure.

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