The Effects of Biaxial Preconditioning on Failure of Acelluluar Collagen Gels

2010 ◽  
Author(s):  
Ryan M. Dean ◽  
Edward A. Sander ◽  
Victor H. Barocas
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Processing Technique ◽  
Scaffold Material ◽  
Structural Protein ◽  
Collagen Gels ◽  
Tissue Engineering Scaffolds ◽  
Structural Support ◽  
Damage And Failure ◽  
Tissue Material

Due to collagen’s importance as an extracellular matrix (ECM) structural protein, it has often been used as a scaffold material for engineered or model tissue [1]. In order to correctly generate new tissues, the scaffolding must mimic the native ECM. The mechanical properties are crucial not only as a structural support but also to allow for cell differentiation [1]. Preconditioning is a processing technique where a sample of soft tissue material is subjected to cyclical strain. As a result, the fibers align in accordance with the direction of preconditioning [2]. Such realignment alters the mechanical properties of the tissue. In order to design more effective tissue engineering scaffolds, it is important to characterize the effects of preconditioning on the damage and failure of collagen constructs. This study attempts to understand how preconditioning alters the stresses, strains, and failure of a sample when it is subjected to a load in different orientations.

scholarly journals Multiscale Mechanical Simulations of Cell Compacted Collagen Gels

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Maziar Aghvami ◽  
V. H. Barocas ◽  
E. A. Sander
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Mechanical Stimulation ◽  
Collagen Gel ◽  
Theoretical Models ◽  
Isometric Tension ◽  
Collagen Gels ◽  
Ecm Remodeling ◽  
Engineered Tissues ◽  
Mechanical Models

Engineered tissues are commonly stretched or compressed (i.e., conditioned) during culture to stimulate extracellular matrix (ECM) production and to improve the mechanical properties of the growing construct. The relationships between mechanical stimulation and ECM remodeling, however, are complex, interdependent, and dynamic. Thus, theoretical models are required for understanding the underlying phenomena so that the conditioning process can be optimized to produce functional engineered tissues. Here, we continue our development of multiscale mechanical models by simulating the effect of cell tractions on developing isometric tension and redistributing forces in the surrounding fibers of a collagen gel embedded with explants. The model predicted patterns of fiber reorganization that were similar to those observed experimentally. Furthermore, the inclusion of cell compaction also changed the distribution of fiber strains in the gel compared to the acellular case, particularly in the regions around the cells where the highest strains were found.

scholarly journals Special Issue: Application of Extracellular Matrix in Regenerative Medicine

2021 ◽  
Vol 11 (7) ◽  
pp. 3262
Author(s):  
Neill J. Turner
Keyword(s):  
Extracellular Matrix ◽  
Regenerative Medicine ◽  
Wound Repair ◽  
Three Dimensional ◽  
Dynamic Structure ◽  
Scaffold Material ◽  
Special Issue ◽  
Organ Regeneration ◽  
Scaffold Materials ◽  
The Many

The present Special Issue comprises a collection of articles addressing the many ways in which extracellular matrix (ECM), or its components parts, can be used in regenerative medicine applications. ECM is a dynamic structure, composed of a three-dimensional architecture of fibrous proteins, proteoglycans, and glycosaminoglycans, synthesized by the resident cells. Consequently, ECM can be considered as nature’s ideal biologic scaffold material. The articles in this Special Issue cover a range of topics from the use of ECM components to manufacture scaffold materials, understanding how changes in ECM composition can lead to the development of disease, and how decellularization techniques can be used to develop tissue-derived ECM scaffolds for whole organ regeneration and wound repair. This editorial briefly summarizes the most interesting aspects of these articles.

scholarly journals Age related extracellular matrix and interstitial cell phenotype in pulmonary valves

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaohua Wu ◽  
Vikas Kumar ◽  
Peng Xiao ◽  
Mitchell Kuss ◽  
Jung Yul Lim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Heart Valve ◽  
Cell Phenotype ◽  
Primary Concern ◽  
Ross Operation ◽  
Age Related ◽  
Cardiovascular Morbidity And Mortality ◽  
Extracellular Matrix Components ◽  
Matrix Components

AbstractHeart valve disease is a common manifestation of cardiovascular disease and is a significant cause of cardiovascular morbidity and mortality worldwide. The pulmonary valve (PV) is of primary concern because of its involvement in common congenital heart defects, and the PV is usually the site for prosthetic replacement following a Ross operation. Although effects of age on valve matrix components and mechanical properties for aortic and mitral valves have been studied, very little is known about the age-related alterations that occur in the PV. In this study, we isolated PV leaflets from porcine hearts in different age groups (~ 4–6 months, denoted as young versus ~ 2 years, denoted as adult) and studied the effects of age on PV leaflet thickness, extracellular matrix components, and mechanical properties. We also conducted proteomics and RNA sequencing to investigate the global changes of PV leaflets and passage zero PV interstitial cells in their protein and gene levels. We found that the size, thickness, elastic modulus, and ultimate stress in both the radial and circumferential directions and the collagen of PV leaflets increased from young to adult age, while the ultimate strain and amount of glycosaminoglycans decreased when age increased. Young and adult PV had both similar and distinct protein and gene expression patterns that are related to their inherent physiological properties. These findings are important for us to better understand the physiological microenvironments of PV leaflet and valve cells for correctively engineering age-specific heart valve tissues.

Enhancement of the Mechanical Properties of PEBAX Graphene Nanocomposite Using Supercritical Fluid Assisted Extrusion Polymer Processing Technique

2017 ◽  
Vol 883 ◽  
pp. 75-84 ◽  
Author(s):  
Nireeksha Karode ◽  
Laurence Fitzhenry ◽  
Siobhán Matthews ◽  
Philip Walsh ◽  
Austin Coffey
Keyword(s):  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Mechanical Performance ◽  
Mechanical Analysis ◽  
Polymer Processing ◽  
Processing Technique ◽  
Graphene Nanocomposites ◽  
Mechanical Tensile ◽  
Supercritical Carbon

Medical tubing used in minimally invasive devices presents a number of design considerations depending on the material used, design requirements (such as sufficient stiffness, flexibility and biocompatibility) and processing conditions. Currently, manufacturing industries adopt co-extrusion systems to meet design specifications, by using multilayer configuration leading to higher cost per device and increased complexity. This paper investigates the mechanical performance of nanocomposites using supercritical carbon dioxide assisted polymer processing technique. The use of innovative medical compounds such as PEBAX graphene nanocomposites have resulted in measurable improvements in mechanical properties. This study also presents the effect of supercritical carbon dioxide on the mechanical and physical properties of the polymer matrix. The mechanical properties have been investigated using dynamic mechanical analysis (DMA) and mechanical tensile test, where sufficient reinforcement was observed depending on the composition of graphene within PEBAX matrix. ATR-FTIR was used to further analyze the effect of supercritical carbon dioxide and interactions within the polymer composite matrix.

Guided differentiation of bone marrow stromal cells on co-cultured cartilage and bone scaffolds

Soft Matter ◽  
2015 ◽  
Vol 11 (38) ◽  
pp. 7648-7655 ◽  
Author(s):  
Paul Lee ◽  
Katelyn Tran ◽  
Gan Zhou ◽  
Asheesh Bedi ◽  
Namdev B. Shelke ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Extracellular Matrix ◽  
Stromal Cells ◽  
Bone Marrow Stromal Cells ◽  
Marrow Stromal Cells ◽  
Bone Scaffolds ◽  
Extracellular Matrix Components ◽  
Matrix Components ◽  
Osteochondral Tissue ◽  
Tissue Material

A biphasic micro and nanostructured scaffold with hydroxyapatite and extracellular matrix components was created for the regeneration of osteochondral tissue. Material cues of the biphasic scaffold supported differentiation of bone marrow stromal cells in both osteogenic and chondrogenic lineages.

scholarly journals Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongfang Qian ◽  
Zhen Zhang ◽  
Laijiu Zheng ◽  
Ruoyuan Song ◽  
Yuping Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weight Ratio ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Tissue Engineering Scaffolds ◽  
Elongation At Break ◽  
Nanofibrous Scaffolds ◽  
Two Peaks

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.

Mechanical properties of decellularized extracellular matrix coated with TiCaPCON film

2017 ◽  
Vol 12 (3) ◽  
pp. 035014 ◽  
Author(s):  
I V Sukhorukova ◽  
A N Sheveyko ◽  
K L Firestein ◽  
Ph V Kiryukhantsev-Korneev ◽  
D Golberg ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Decellularized Extracellular Matrix

Reconstituted Extracellular Matrix Improve Osteoblastic Differentiation onto Titanium Surfaces

2012 ◽  
Vol 706-709 ◽  
pp. 584-588
Author(s):  
Lia Rimondini ◽  
Federica Demarosi ◽  
Ismaela Foltran ◽  
Nadia Quirici
Keyword(s):  
Extracellular Matrix ◽  
Electrostatic Force ◽  
Biological Tissues ◽  
Osteoblastic Differentiation ◽  
Cell Phenotype ◽  
Tissue Engineering Scaffolds ◽  
Electrospinning Technique ◽  
Differentiation Potential ◽  
Oral Implants

Electrospinning technique is an efficient processing method to manufacture micro-and nanosized fibrous structures by electrostatic force for different applications. In biomaterial field, electrospinning technique has been successfully utilized to prepare new drug delivery materials and tissue engineering scaffolds. Fiber mats of biodegradable polymers having a diameter in the nanoto submicro-scale can be considered to mimic the nanofibrous structure of native extracellular matrix (ECM). Native extracellular matrix, constituted of proteins and polysaccharides improving cells growth in its nanofibrous porous structure, controls not only the cell phenotype, but the whole structure of the biological tissues. In the present study we investigated the effect of electrospun reconstituted collagen fibers onto metals for oral implants devices manufacturing as far as the osteoblastic differentiation potential of stem cells and cytofunctionality of osteoblasts in-vitro. The cells cultured onto titanium samples coated with ECM constituents showed faster osteoblastic differentiation and more efficient deposition of mineralized matrix in comparison with those onto uncoated substrates.

Effect of the extracellular matrix on plasminogen activator isozyme activities of human mammary epithelial cells in culture

1983 ◽  
Vol 3 (6) ◽  
pp. 982-990
Author(s):  
N S Yang ◽  
C Park ◽  
C Longley ◽  
P Furmanski
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Plasminogen Activator ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Collagen Gels ◽  
Human Mammary Epithelial Cells ◽  
Human Mammary Epithelial ◽  
Normal Human ◽  
Mcf 7

Multiple molecular forms of plasminogen activator were detected in normal human mammary epithelial cells in culture. Cells derived from (normal) breast mammoplasty specimens and grown on the surface of collagen gels exhibited three major classes of plasminogen activator isozymes (Mr = 100,000 [100K], 75,000 [75K], and 55,000 [55K]). The activity of the 100K and 75K isozymes was greatly reduced when the cells were grown on conventional tissue-culture-grade plastic surfaces. MCF-7, a human mammary carcinoma cell line, exhibited predominantly or exclusively the 55K isozyme, irrespective of the cell growth substratum. The activity of the 55K isozyme was more than twofold higher for MCF-7 cells grown on collagen gels than for cells grown on plastic. Progesterone, diethylstilbestrol, and estrogen stimulated the activity of the 55K isozyme of MCF-7 cells, but only when the cells were grown on a plastic surface. The plasminogen activator activities of the normal human mammary epithelial cells were not stimulated by these hormones, irrespective of the growth substratum. These results show that the expression of plasminogen activator isozymes by human mammary epithelial cells is subject to modulation by the extracellular matrix. Normal and malignant cells may differ in their responsiveness to these effects.

Regulation of human lung fibroblast phenotype and function by vitronectin and vitronectin integrins

2001 ◽  
Vol 114 (19) ◽  
pp. 3507-3516 ◽  
Author(s):  
Amelia K. Scaffidi ◽  
Yuben P. Moodley ◽  
Markus Weichselbaum ◽  
Philip J. Thompson ◽  
Darryl A. Knight
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Monoclonal Antibodies ◽  
Human Lung ◽  
Stress Fibers ◽  
Collagen Gels ◽  
Human Lung Fibroblast ◽  
Myofibroblast Phenotype ◽  
And Function ◽  
Blocking Antibodies

Myofibroblasts, characterised by high expression of α-smooth muscle actin (α-SMA), are important and transient cells in normal wound healing but are found in increased number in various pathological conditions of the lung including asthma and pulmonary fibrosis. The mechanisms that regulate the myofibroblast phenotype are unknown but are likely to involve signals from the extracellular matrix transmitted via specific integrins. Vitronectin is a glycoprotein released during inflammation and has been shown to regulate the phenotype of vascular smooth muscle cells via αv and β1 integrins. In the current study we have examined whether vitronectin influences the phenotype and function of normal human lung fibroblasts (HFL-1). Incubation of HFL-1 cells with vitronectin induced a concentration-dependent reduction in α-SMA expression. By contrast, function-blocking monoclonal antibodies to the vitronectin integrins αv, β1, αvβ3 and αvβ5 induced the expression of α-SMA and its organization into stress fibers. Expression of α-SMA induced by all function-blocking monoclonal antibodies was abrogated by inhibition of protein kinase C and phosphatidylinositol-3 kinase, but the effects of inhibition of other signalling pathways was integrin dependent. Exposure to other extracellular matrix proteins such as fibronectin, collagen or their integrins did not influence expression of α-SMA. The expression and organization of α-SMA induced by exposure to function-blocking antibodies was translated into an augmented capacity of HFL-1 cells to contract fibroblast populated collagen gels. By contrast, contraction of collagen gels following incubation with vitronectin was not significantly different to control. This study has shown that vitronectin influences the phenotype and behaviour of HFL-1 cells by downregulating the expression of α-SMA and reducing their contractile ability. By contrast, occupancy of specific integrins by function-blocking antibodies upregulated the expression of α-SMA and induced the formation of functional stress fibers capable of contracting collagen gels. These results suggest that vitronectin modulates the fibroblast-myofibroblast phenotype, implying an important role in the remodelling process during lung development or response to injury.

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