Electrochemical Compaction of the Collagen: Effects on Matrix Mechanics and MSC Response

The molecules of the extracellular matrix in connective tissues are densely packed. Biofabrication methods to attain such molecular packing density are limited and electrochemical processing (EP) of monomeric collagen solutions is one of few means to attain molecular packing. During EP, the pH gradient between electrodes drives the electrophoretic mobility of collagen molecules toward the isoelectric point where molecules are compacted. Our earlier work used linear electrodes to fabricate highly aligned crosslinked collagen fibers for tendon tissue engineering [1–4]. Prior work compared electrocompacted-aligned matrices with uncompacted randomly oriented ones. Therefore, the effects of alignment and compaction were compounded in terms of assessing cell response. So as to take the matrix alignment variable out of the picture to investigate matrix compaction effects only, we employed disc shaped electrodes to obtain electrocompacted sheets which lack matrix alignment. The current study investigated: a) the degree of compaction, b) effect of compaction on the mechanical properties of the sheets, and, c) mesenchymal stem cell (MSC) proliferation and morphology on compacted sheets relative to uncompacted collagen gels.

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Fibrin Gels Exhibit Improved Biological, Structural, and Mechanical Properties Compared with Collagen Gels in Cell-Based Tendon Tissue-Engineered Constructs

Tissue Engineering Part A ◽

10.1089/ten.tea.2013.0768 ◽

2015 ◽

Vol 21 (3-4) ◽

pp. 438-450 ◽

Cited By ~ 30

Author(s):

Andrew P. Breidenbach ◽

Nathaniel A. Dyment ◽

Yinhui Lu ◽

Marepalli Rao ◽

Jason T. Shearn ◽

...

Keyword(s):

Mechanical Properties ◽

Collagen Gels ◽

Tendon Tissue ◽

Fibrin Gels

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Improving the Anisotropy of Collagen by Electric Field Increases Its Toughness by Two-Fold

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176705 ◽

2007 ◽

Author(s):

Xingguo Cheng ◽

Nicholas Wasserman ◽

Ozan Akkus

Keyword(s):

Mechanical Properties ◽

Tissue Regeneration ◽

Hierarchical Organization ◽

Great Promise ◽

Structural Protein ◽

Connective Tissues ◽

Major Structural Protein ◽

Collagen Molecules ◽

Specific Tissue

Collagen is the major structural protein in the connective tissues such as skin, bone, ligaments, and tendons. The specific hierarchical organization of collagen molecules determines the unique properties of each specific tissue. For example, in tendon, the parallel alignment of collagen molecules, fibrils, fibril bundles, fascicles and tendon units gives tendon good mechanical properties. Thus, in vitro engineering of collagen molecules hold great promise as a tissue regeneration material. However, there is a need for mechanically superior collagenous structures, which currently cannot be provided by isotropic gels which lack defined orientation. Increasing the anisotropy of gels would increase the strength of collagenous constructs tremendously.

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A Study on the Mechanical Properties of the Representative Volume Element in Fractal Porous Media

Geofluids ◽

10.1155/2017/7905218 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Jianjun Liu ◽

Mingyang Wu ◽

Zhengwen Zhu ◽

Zuliang Shao

Keyword(s):

Mechanical Properties ◽

Porous Media ◽

Fractal Dimension ◽

Representative Volume Element ◽

Mechanical Response ◽

Volume Element ◽

Structure Generation ◽

Matrix Mechanics ◽

Representative Volume ◽

The Matrix

Natural porous structure is extremely complex, and it is of great significance to study the macroscopic mechanical response of the representative volume element (RVE) with the microstructure of porous media. The real porous media RVE is generated by an improved quartet structure generation set (QSGS), and the connectivity of the reconstructed porous media models is analyzed. The fractal dimension of the RVE is calculated by the box-counting method, which considers the different porosity, different fractal dimension, and different mechanical properties of the matrix. Thus, the stress-strain curves of the RVE in the elastoplastic stage under different conditions are obtained. The results show that when the matrix mechanics are consistent, the mechanical properties of the porous media RVE are negatively correlated with the porosity and fractal dimension; when the difference between the porosity and fractal dimension increases, the trend is more obvious. The mechanical properties of the RVE have a positive correlation with the modulus of elasticity of the matrix, though the correlation with Poisson’s ratio of the matrix is weak. The fractal dimension of complex porous media can better predict the RVE mechanical characteristics than the porosity.

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Morphology and Mechanical Properties of Polyethylene Terephthalate/Ethylene Propylene Diene Monomer (PET/EPDM) in the Presence of Nanoclay

Materiale Plastice ◽

10.37358/mp.20.3.5397 ◽

2020 ◽

Vol 57 (3) ◽

pp. 249-259

Author(s):

Baifen Liu ◽

Mohammad Mirjalili ◽

Peiman Valipour ◽

Sajad Porzal ◽

shirin Nourbakhsh

Keyword(s):

Mechanical Properties ◽

Impact Strength ◽

Thermal Destruction ◽

Processing Temperature ◽

Tem Analysis ◽

Maximum Stiffness ◽

Cloisite 30B ◽

Nano Clay ◽

The Matrix ◽

Sample Maximum

This research deals with the mechanical properties, microstructure, and interrelations of triple nanocomposite based on PET/EPDM/Nanoclay. These properties were examined in different percentages of PET/EPDM blend with compatibilizer (Styrene-Ethylene/Butylene-Styrene)-G-(Maleic anhydrate) (SEBS-g-MAH). Results showed that the addition of 15% SEBS-g-MAH improved the toughness and impact strength of this nanocomposite. SEM micrographs indicated the most stable fuzzy microstructure in a 50/50 mixture of scattered phases of EPDM/SEBS-g-MAH. The effects of percentages of 1, 3, 5, 7 nanoclay Cloisite 30B (C30B) on the improvement of the properties were evaluated. With the addition of nano clay, the toughness and impact strength was reduced. Thermal destruction of nanoclay in processing temperature led to the decreasing dispersion of clay plates in the matrix and a reduction in the distances of nano clay plates in the composite compared to pure nano clay. XRD and TEM analysis was used to demonstrate the results. By adding 1% of nanoclay to the optimal sample, maximum stiffness, and Impact strength, among other nanocomposites, was achieved.

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Effects of the interfacial stress-induced crystallization on the matrix crystalline morphology and the mechanical properties of glass fiber-reinforced high density polyethylene composites

Journal of Adhesion Science and Technology ◽

10.1163/156856100742267 ◽

2000 ◽

Vol 14 (11) ◽

pp. 1405-1421 ◽

Cited By ~ 10

Author(s):

Yuncan Zhang ◽

Ruizhu Chen ◽

Zhongzhi Hui

Keyword(s):

Mechanical Properties ◽

Glass Fiber ◽

High Density Polyethylene ◽

High Density ◽

Interfacial Stress ◽

Crystalline Morphology ◽

Glass Fiber Reinforced ◽

The Matrix ◽

Stress Induced Crystallization ◽

Induced Crystallization

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Preparation of Long Sisal Fiber-Reinforced Polylactic Acid Biocomposites with Highly Improved Mechanical Performance

Polymers ◽

10.3390/polym13071124 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1124

Author(s):

Zhifang Liang ◽

Hongwu Wu ◽

Ruipu Liu ◽

Caiquan Wu

Keyword(s):

Mechanical Properties ◽

Polylactic Acid ◽

Mechanical Performance ◽

Tensile Elongation ◽

Sisal Fiber ◽

Fiber Reinforced ◽

Impact Performance ◽

The Matrix ◽

Blending Process ◽

Extension Direction

Green biodegradable plastics have come into focus as an alternative to restricted plastic products. In this paper, continuous long sisal fiber (SF)/polylactic acid (PLA) premixes were prepared by an extrusion-rolling blending process, and then unidirectional continuous long sisal fiber-reinforced PLA composites (LSFCs) were prepared by compression molding to explore the effect of long fiber on the mechanical properties of sisal fiber-reinforced composites. As a comparison, random short sisal fiber-reinforced PLA composites (SSFCs) were prepared by open milling and molding. The experimental results show that continuous long sisal fiber/PLA premixes could be successfully obtained from this pre-blending process. It was found that the presence of long sisal fibers could greatly improve the tensile strength of LSFC material along the fiber extension direction and slightly increase its tensile elongation. Continuous long fibers in LSFCs could greatly participate in supporting the load applied to the composite material. However, when comparing the mechanical properties of the two composite materials, the poor compatibility between the fiber and the matrix made fiber’s reinforcement effect not well reflected in SSFCs. Similarly, the flexural performance and impact performance of LSFCs had been improved considerably versus SSFCs.

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A poly(arylene ether sulfone) hybrid membrane using titanium dioxide nanoparticles as the filler

High Performance Polymers ◽

10.1177/0954008315626990 ◽

2016 ◽

Vol 29 (1) ◽

pp. 26-35 ◽

Cited By ~ 10

Author(s):

Yunwu Yu ◽

Wenhao Pan ◽

Xiaoman Guo ◽

Lili Gao ◽

Yaxin Gu ◽

...

Keyword(s):

Mechanical Properties ◽

Titanium Dioxide ◽

Gas Separation ◽

Proton Nuclear Magnetic Resonance ◽

Separation Performance ◽

Hydroxyl Groups ◽

Hybrid Membranes ◽

Permeability Coefficients ◽

Arylene Ether ◽

The Matrix

Poly(arylene ether sulfone) (PES)–titanium dioxide (TiO2) hybrid membranes were prepared via solution blending method using TiO2 nanoparticles as inorganic filler. The chemical structure and thermal stability of the matrix polymer were characterized by proton nuclear magnetic resonance, Fourier transform infrared, differential scanning calorimetry, and thermogravimetric analysis. The crystal structure, morphology, mechanical properties, and gas separation performance of hybrid membranes were characterized in detail. As shown in scanning electron microscopic images, TiO2 nanoparticles dispersed homogeneously in the matrix. Although the mechanical properties of hybrid membranes decreased certainly compared to the pure PES membranes, they are strong enough for gas separation in this study. All gas permeability coefficients of PES-TiO2 hybrid membranes were higher than pure PES membranes, attributed to the nanogap caused by TiO2 nanoparticles, for instance, oxygen and nitrogen permeability coefficients of Hybrid-3 (consists of PES with 4-amino-phenyl pendant group and hexafluoroisopropyl (Am-PES)-20 and TiO2 nanoparticles, 5 wt%) increased from 2.57 and 0.33 to 5.88 and 0.63, respectively. In addition, the separation factor increased at the same time attributed to the stimulative transfer effect caused by the interaction of hydroxyl groups on the TiO2 nanoparticle and polar carbon dioxide molecules.

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Tendon-bioinspired wavy nanofibrous scaffolds provide tunable anisotropy and promote tenogenesis for tendon tissue engineering

Materials Science and Engineering C ◽

10.1016/j.msec.2021.112181 ◽

2021 ◽

pp. 112181

Author(s):

Shaohua Wu ◽

Jiao Liu ◽

Ye Qi ◽

Jiangyu Cai ◽

Jinzhong Zhao ◽

...

Keyword(s):

Tissue Engineering ◽

Tendon Tissue ◽

Nanofibrous Scaffolds ◽

Tendon Tissue Engineering

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Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

Metals ◽

10.3390/met11040548 ◽

2021 ◽

Vol 11 (4) ◽

pp. 548 ◽

Cited By ~ 1

Author(s):

Leonid Agureev ◽

Valeriy Kostikov ◽

Zhanna Eremeeva ◽

Svetlana Savushkina ◽

Boris Ivanov ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

Strength Properties ◽

Alumina Nanoparticles ◽

Metal Powders ◽

Wide Range ◽

The Matrix ◽

Spark Plasma ◽

Average Size

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.

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