scholarly journals INFLUENCE OF DIFFERENT POLYMER CONCENTRATIONS ON THE STRUCTURE OF MICROFIBERS IN THE FIBROUS MATRIX

2021 ◽  
Vol 1 (1) ◽  
pp. 174
Author(s):  
A. V. Pantus ◽  
M. M. Rozhko ◽  
N. E. Kovalchuk ◽  
I. R. Yarmoshuk
Keyword(s):  
Fibrous Matrix

scholarly journals Artificial Cardiac Muscle with or without the Use of Scaffolds

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Yifei Li ◽  
Donghui Zhang
Keyword(s):  
Tissue Engineering ◽  
Cardiovascular Diseases ◽  
Cardiac Tissue ◽  
Contractile Function ◽  
Rapid Development ◽  
Treatment Options ◽  
Cardiac Tissue Engineering ◽  
Hydrogel Scaffold ◽  
Fibrous Matrix ◽  
Advantages And Disadvantages

During the past several decades, major advances and improvements now promote better treatment options for cardiovascular diseases. However, these diseases still remain the single leading cause of death worldwide. The rapid development of cardiac tissue engineering has provided the opportunity to potentially restore the contractile function and retain the pumping feature of injured hearts. This conception of cardiac tissue engineering can enable researchers to produce autologous and functional biomaterials which represents a promising technique to benefit patients with cardiovascular diseases. Such an approach will ultimately reshape existing heart transplantation protocols. Notable efforts are accelerating the development of cardiac tissue engineering, particularly to create larger tissue with enhanced functionality. Decellularized scaffolds, polymer synthetics fibrous matrix, and natural materials are used to build robust cardiac tissue scaffolds to imitate the morphological and physiological patterns of natural tissue. This ultimately helps cells to implant properly to obtain endogenous biological capacity. However, newer designs such as the hydrogel scaffold-free matrix can increase the applicability of artificial tissue to engineering strategies. In this review, we summarize all the methods to produce artificial cardiac tissue using scaffold and scaffold-free technology, their advantages and disadvantages, and their relevance to clinical practice.

The air permeability of composite fiber material

2021 ◽  
Vol 1 ◽  
pp. 42-48
Author(s):  
T. A. Leshchenko ◽  
◽  
N. V. Chernousova ◽  
A. V. Dedov ◽  
◽  
...  
Keyword(s):  
Composite Materials ◽  
Permeability Coefficient ◽  
Pore Space ◽  
Fiber Material ◽  
Composite Fiber ◽  
Air Permeability ◽  
Rubber Content ◽  
Limited Mobility ◽  
Fibrous Matrix ◽  
Composite Fiber Material

The air permeability of composite materials obtained by impregnating a non-woven needle-punched cloth with latex was investigated. The permeability of composite materials with different rubber content was estimated by the coefficient of air permeability at a pressure drop of 49 and 100 Pa. The dependence of the air permeability coefficient on the degree of impregnation of the fabric showed that at 15 – 20 % of the rubber content, the maximum air permeability coefficient is observed, and when the degree of impregnation increases, the air permeability coefficient decreases. The process of forming a porous structure of composite materials and its influence on air transport is considered. The increase of the coefficient of permeability is explained by the fixation of the fibers of the surface layer with limited mobility under the action of air flow, and a reduction in the coefficient of air permeability by reducing pore space and an increase in fiber matrix composite materials in the process of sushi-Ki-impregnated material. The air permeability of composite materials is determined by the ratio between the processes of increasing the volume of the fibrous matrix and reducing porosity when filling the space between the portages with rubber particles. A model is proposed for calculating the coefficient of breathability of composite materials of known density.

Diversity and Evolution of Mineralized Skeletal Tissues in Chondrichthyans

2021 ◽  
Vol 9 ◽  
Author(s):  
Fidji Berio ◽  
Morgane Broyon ◽  
Sébastien Enault ◽  
Nelly Pirot ◽  
Faviel A. López-Romero ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Phylogenetic Relationships ◽  
Current Knowledge ◽  
Neural Arch ◽  
Fossil Species ◽  
Fibrous Matrix ◽  
Cartilaginous Matrix ◽  
Mineralized Tissues ◽  
Early Vertebrates ◽  
Cartilaginous Fishes

The diversity of skeletal tissues in extant vertebrates includes mineralized and unmineralized structures made of bone, cartilage, or tissues of intermediate nature. This variability, together with the diverse nature of skeletal tissues in fossil species question the origin of skeletonization in early vertebrates. In particular, the study of skeletal tissues in cartilaginous fishes is currently mostly restrained to tessellated cartilage, a derived form of mineralized cartilage that evolved at the origin of this group. In this work, we describe the architectural and histological diversity of neural arch mineralization in cartilaginous fishes. The observed variations in the architecture include tessellated cartilage, with or without more massive sites of mineralization, and continuously mineralized neural arches devoid of tesserae. The histology of these various architectures always includes globular mineralization that takes place in the cartilaginous matrix. In many instances, the mineralized structures also include a fibrous component that seems to emerge from the perichondrium and they may display intermediate features, ranging from partly cartilaginous to mostly fibrous matrix, similar to fibrocartilage. Among these perichondrial mineralized tissues is also found, in few species, a lamellar arrangement of the mineralized extracellular matrix. The evolution of the mineralized tissues in cartilaginous fishes is discussed in light of current knowledge of their phylogenetic relationships.

scholarly journals RNA Binding Proteins Control Transdifferentiation of Hepatic Stellate Cells into Myofibroblasts

2018 ◽  
Vol 48 (3) ◽  
pp. 1215-1229 ◽  
Author(s):  
Sihyung Wang ◽  
Youngmi Jung ◽  
Jeongeun Hyun ◽  
Matthew Friedersdorf ◽  
Seh-Hoon Oh ◽  
...  
Keyword(s):  
Hepatic Stellate Cells ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Stellate Cells ◽  
Fibrous Matrix ◽  
Rna Immunoprecipitation ◽  
Physical Interactions ◽  
Β Receptor ◽  
Dependent Mechanism

Background/Aims: Myofibroblasts (MF) derived from quiescent nonfibrogenic hepatic stellate cells (HSC) are the major sources of fibrous matrix in cirrhosis. Because many factors interact to regulate expansion and regression of MF-HSC populations, efforts to prevent cirrhosis by targeting any one factor have had limited success, motivating research to identify mechanisms that integrate these diverse inputs. As key components of RNA regulons, RNA binding proteins (RBPs) may fulfill this function by orchestrating changes in the expression of multiple genes that must be coordinately regulated to affect the complex phenotypic modifications required for HSC transdifferentiation. Methods: We profiled the transcriptomes of quiescent and MF-HSC to identify RBPs that were differentially-expressed during HSC transdifferentiation, manipulated the expression of the most significantly induced RBP, insulin like growth factor 2 binding protein 3 (Igf2bp3), and evaluated transcriptomic and phenotypic effects. Results: Depleting Igf2bp3 changed the expression of thousands of HSC genes, including multiple targets of TGF-β signaling, and caused HSCs to reacquire a less proliferative, less myofibroblastic phenotype. RNA immunoprecipitation assays demonstrated that some of these effects were mediated by direct physical interactions between Igf2bp3 and mRNAs that control proliferative activity and mesenchymal traits. Inhibiting TGF-β receptor-1 signaling revealed a microRNA-dependent mechanism that induces Igf2bp3. Conclusions: The aggregate results indicate that HSC transdifferentiation is ultimately dictated by Igf2bp3-dependent RNA regulons and thus, can be controlled simply by manipulating Igf2bp3.

Equivalent Mixed “PHETS” and “MPHETS” Poroelasttc-Transport-Swelling Finite Element Models for Soft Biological Tissues

1999 ◽  
Author(s):  
B. R. Simon ◽  
S. K. Williams ◽  
J. Liu ◽  
J. W. Nichol ◽  
P. H. Rigby ◽  
...  
Keyword(s):  
Finite Element ◽  
Chemical Potential ◽  
Biological Tissues ◽  
Finite Element Models ◽  
Material Interfaces ◽  
Soft Biological Tissues ◽  
Fibrous Matrix ◽  
Charged Species ◽  
Pressure Fields ◽  
Swelling Model

Abstract A soft hydrated tissue structure can be viewed as a “PETS” (poroelastic-transport-swelling) model, i.e., as a continuum composed of an incompressible porous solid (fibrous matrix with fixed charge density, FCD) that is saturated by a mobile incompressible fluid (water) containing mobile positively (p) and negatively (m) charged species. Previously, we described two PETS models — a “semi-mixed” porohyperelastic PHETS model (Simon et al. 1998) and a “fully mixed” MPHETS model (Simon et al. 1999) using FEMs (finite element models) that included geometric and material nonlinearity and coupled electrical/chemical/mechanical transport of the fluid and charged species. Here, we demonstrate the equivalence of the PHETS and MPHETS formulations that are useful when the solid and fluid materials are incompressible and the electrical-chemical potential and mechanical-osmotic pressure fields are discontinuous at material interfaces.

A Functional Basis For The Platelet Storage Pool Deficiency In Chediak-Higashi Cattle

1981 ◽  
Author(s):  
K M Meyers ◽  
M Fukami ◽  
H Holmsen
Keyword(s):  
Freeze Fracture ◽  
Subcellular Fractionation ◽  
Dense Granule ◽  
Bivalent Cation ◽  
Fibrous Matrix ◽  
Dense Granules ◽  
Storage Pool ◽  
Common Basis ◽  
Platelet Storage ◽  
Amine Storage

Platelets from cattle with the morphologic homolog of the Chediak-Higashi (CH) syndrome are essentially devoid of secretable nucleotides and serotonin. There are reduced but still substantial amounts of secretable calcium and magnesium. The storage pool deficiency may be, in part, due to a functional granule defect. Platelets from CH cattle take up serotonin and protect it from degradation for several hours. If these platelets are treated with thrombin, serotonin and bivalent cations are released by mechanisms similar to that of secretion, suggesting a granule location for the released serotonin and cations. This suggestion is verified by subcellular fractionation studies where platelets are first incubated with 14C-serotonin then lysed using a French press. Organelles were then separated on a sucrose gradient by centrifugation. Serotonin in normal bovine platelets is associated with the dense granule or pellet while in CH platelets serotonin is primarily found in a region of the sucrose density zone that in normal platelets contain alpha granules. These findings suggested that some granules in CH platelets are able to acquire the bivalent cation and amine but not the nucleotide component of the bivalent cation-nucleotide-amine storage complex that is thought to occur in normal dense granules.Ultrastructural identification of the serotonin-containing CH granule is not known. There are 2 identifiable granule populations in CH platelets, alpha granules and fibrous matrix granules. Based on serial sectioning freeze fracture and morphometric studies, there are less than 4 of these granules/platelet. Mepacrine studies also demonstrate 2 granule populations. One population has an incidence of 2 per granule and characteristics of normal dense granules. Since the number of fibrous matrix granules and mepacrine granules is similar, a common basis for these granules which has at least some dense granule characteristics, i.e., mepacrine storage, is suggested.

Sectorial Analysis of the Fibrous Matrix of Vocal Folds in the Elderly

2020 ◽  
Author(s):  
Adriana Bueno Benito Pessin ◽  
Regina Helena Garcia Martins ◽  
Lucas Fernando Sergio Gushiken ◽  
Claudia Helena Pellizzon
Keyword(s):  
Vocal Folds ◽  
The Elderly ◽  
Fibrous Matrix ◽  
Sectorial Analysis

scholarly journals Matrix-transmitted paratensile signaling enables myofibroblast–fibroblast cross talk in fibrosis expansion

2020 ◽  
Vol 117 (20) ◽  
pp. 10832-10838 ◽  
Author(s):  
Longwei Liu ◽  
Hongsheng Yu ◽  
Hui Zhao ◽  
Zhaozhao Wu ◽  
Yi Long ◽  
...  
Keyword(s):  
Cross Talk ◽  
Growth Models ◽  
Tissue Level ◽  
Dependent Manner ◽  
Cell Level ◽  
Fibrous Matrix ◽  
Calcium Dependent ◽  
Spatiotemporal Feature ◽  
Fibroblast Foci

While the concept of intercellular mechanical communication has been revealed, the mechanistic insights have been poorly evidenced in the context of myofibroblast–fibroblast interaction during fibrosis expansion. Here we report and systematically investigate the mechanical force-mediated myofibroblast–fibroblast cross talk via the fibrous matrix, which we termed paratensile signaling. Paratensile signaling enables instantaneous and long-range mechanotransduction via collagen fibers (less than 1 s over 70 μm) to activate a single fibroblast, which is intracellularly mediated by DDR2 and integrin signaling pathways in a calcium-dependent manner through the mechanosensitive Piezo1 ion channel. By correlating in vitro fibroblast foci growth models with mathematical modeling, we demonstrate that the single-cell-level spatiotemporal feature of paratensile signaling can be applied to elucidate the tissue-level fibrosis expansion and that blocking paratensile signaling can effectively attenuate the fibroblast to myofibroblast transition at the border of fibrotic and normal tissue. Our comprehensive investigation of paratensile signaling in fibrosis expansion broadens the understanding of cellular dynamics during fibrogenesis and inspires antifibrotic intervention strategies targeting paratensile signaling.

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