Collagen-based biocomposites inspired by bone hierarchical structures advanced bone regeneration: Ongoing research and perspectives

2021 ◽  
Author(s):  
Di Qin ◽  
Na Wang ◽  
Xin-Guo You ◽  
Andi Zhang ◽  
Xiguang Chen ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Bone Regeneration ◽  
Hierarchical Structure ◽  
Type I Collagen ◽  
Hierarchical Structures ◽  
Collagen Fibers ◽  
Type I ◽  
Ongoing Research ◽  
The Matrix

Bone is a hard-connective tissue composed of matrix, cells and bioactive factors with hierarchical structure, where the matrix is mainly composed of type I collagen and hydroxyapatite. Collagen fibers assembled...

scholarly journals MT1-MMP directs force-producing proteolytic contacts that drive tumor cell invasion

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Robin Ferrari ◽  
Gaëlle Martin ◽  
Oya Tagit ◽  
Alan Guichard ◽  
Alessandra Cambi ◽  
...  
Keyword(s):  
Actin Polymerization ◽  
Type I Collagen ◽  
Collagen Matrix ◽  
Collagen Fibers ◽  
Ultrastructural Organization ◽  
Type I ◽  
The Matrix ◽  
Cancer Spread ◽  
Electron Microscopy Analysis ◽  
And Function

Abstract Unraveling the mechanisms that govern the formation and function of invadopodia is essential towards the prevention of cancer spread. Here, we characterize the ultrastructural organization, dynamics and mechanical properties of collagenotytic invadopodia forming at the interface between breast cancer cells and a physiologic fibrillary type I collagen matrix. Our study highlights an uncovered role for MT1-MMP in directing invadopodia assembly independent of its proteolytic activity. Electron microscopy analysis reveals a polymerized Arp2/3 actin network at the concave side of the curved invadopodia in association with the collagen fibers. Actin polymerization is shown to produce pushing forces that repel the confining matrix fibers, and requires MT1-MMP matrix-degradative activity to widen the matrix pores and generate the invasive pathway. A theoretical model is proposed whereby pushing forces result from actin assembly and frictional forces in the actin meshwork due to the curved geometry of the matrix fibers that counterbalance resisting forces by the collagen fibers.

Assembly of Type I Collagen on PVA Film Induced by Glutaraldehyde Vapor

2011 ◽  
Vol 284-286 ◽  
pp. 1794-1799 ◽  
Author(s):  
Yu Lu Wang ◽  
Xue Pin Liao ◽  
Bi Shi
Keyword(s):  
Network Structure ◽  
Type I Collagen ◽  
Collagen Fibers ◽  
Type I ◽  
Collagen Concentration ◽  
Collagen Molecules ◽  
Induced Reaction ◽  
Calf Skin

Type I collagen was isolated from calf skin and its assembly on PVA film induced by glutaraldehyde vapor was investigated. It was found that the collagen molecules were firstly orientationally assembled into collagen fibers under the inducement of glutaraldehyde vapor. Then the collagen fibers could be further aggregated into novel network structure in proper conditions of the induced reaction. The morphology of the assembled collagen fibers was depended on induced time and concentration of collagen. The network arrangement could be obtained after being induced for 72h when collagen concentration was 2.5mg/ml. At higher concentration of collagen (5 mg/ml), the collagen fibers with larger dimension were obtained, but the growth of fibers was almost in one direction.

scholarly journals Existence and Features of the Myodural Bridge in Gentoo Penguins: a morphological study

2020 ◽  
Author(s):  
Cheng Chen ◽  
Sheng-bo Yu ◽  
Yan-yan Chi ◽  
Guang-yuan Tan ◽  
Bao-cheng Yan ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Dura Mater ◽  
Type I Collagen ◽  
Morphological Characteristics ◽  
Gentoo Penguin ◽  
Type I ◽  
Marine Birds ◽  
Dense Connective Tissue ◽  
Myodural Bridge ◽  
Histological Staining

AbstractRecent studies have evidenced that the anatomical structure now known as the myodural bridge (MDB) connects the suboccipital musculature to the cervical spinal dura mater (SDM). In humans, the MDB passes through both the posterior atlanto-occipital and the posterior atlanto-axial interspaces. The present authors suggest that the MDB has important physiological functions in humans. The existence of the MDB in various mammals, including flying birds (Rock pigeons and Gallus domesticus) has been previously validated. Gentoo penguins are marine birds, able to make 450 dives per day, reaching depths of up to 660 feet. Gentoo penguins are also the world’s fastest diving birds. The present study was therefore carried out to investigate the existence and characteristics of the MDB in Gentoo penguin (Pygoscelis papua), a non-flying, marine bird that can dive. While foraging, this penguin is able to reach speeds of up to 22 miles per hour. For this study, six Gentoo penguin specimens were dissected to observe the existence and composition of their MDB. Histological staining was also performed to analyze the anatomic relationships and characteristic of the MDB in the Gentoo penguin. In this study, it was found that the suboccipital musculature in the Gentoo penguin consists of the rectus capitis dorsalis minor (RCDmi) muscle and rectus capitis dorsalis major (RCDma) muscle. Dense connective tissue fibers were observed connecting these two suboccipital muscles to the spinal dura mater (SDM). This dense connective tissue bridge consists of primarily type I collagen fibers. Thus, this penguin’s MDB appears to be analogous to the MDB previously observed in humans. The present study evidences that the MDB not only exists in penguins but it also has unique features that distinguishes it from that of flying birds. Thus, this study advances the understanding of the morphological characteristics of the MDB in flightless, marine birds.

Cytoskeleton and thyroglobulin expression change during transformation of thyroid epithelium to mesenchyme-like cells

Development ◽  
1988 ◽  
Vol 102 (3) ◽  
pp. 605-622 ◽  
Author(s):  
G. Greenburg ◽  
E.D. Hay
Keyword(s):  
Type I Collagen ◽  
Collagen Gel ◽  
Type I ◽  
Basal Cells ◽  
Collagen Gels ◽  
Expression Change ◽  
Cell Functions ◽  
The Matrix ◽  
3D Matrix ◽  
Mesenchymal Transformation

In considering the mechanism of transformation of epithelium to mesenchyme in the embryo, it is generally assumed that the ability to give rise to fibroblast-like cells is lost as epithelia mature. We reported previously that a definitive embryonic epithelium, that of the anterior lens, gives rise to freely migrating mesenchyme-like cells when suspended in type I collagen matrices. Here, we show that a highly differentiated epithelium that expresses cytokeratin changes to a vimentin cytoskeleton and loses thyroglobulin during epithelial-mesenchymal transformation induced by suspension in collagen gel. Using dispase and collagenase, we isolated adult thyroid follicles devoid of basal lamina and mesenchyme, and we suspended the follicles in 3D collagen gels. Cells bordering the follicle lumen retain epithelial polarity and thyroid phenotype, but basal cell surface organization is soon modified as a result of tissue multilayering and elongation of basal cells into the collagenous matrix. Cytodifferentiation, determined by thyroglobulin immunoreactivity, is lost as the basal epithelial cells move into the matrix after 3–4 days in collagen. By TEM, it can be seen that the elongating cells acquire pseudopodia, filopodia and mesenchyme-like nuclei and RER. Immunofluorescence examination of intermediate filaments showed that freshly isolated follicles and follicles cultured on planar substrata react only with anticytokeratin. However, all of the mesenchyme-like cells express vimentin and they gradually lose cytokeratin. These results suggest that vimentin may be necessary for cell functions associated with migration within a 3D matrix. The mesenchymal cells do not revert to epithelium when grown on planar substrata and the transformation of epithelium to mesenchyme-like cells does not occur within basement membrane gels. The results are relevant to our understanding of the initiation of epithelial-mesenchymal transformation in the embryo and the genetic mechanisms controlling cell shape, polarity and cytoskeletal phenotype.

scholarly journals Inhibition of Collagen-Induced Platelet Aggregation by Antibodies to Distinct Types of Collagen

1977 ◽  
Author(s):  
L. Balleisen ◽  
R. Timpl ◽  
S. Gay
Keyword(s):  
Platelet Aggregation ◽  
Serum Albumin ◽  
Type I Collagen ◽  
Collagen Fibers ◽  
Type Iii Collagen ◽  
Type I ◽  
Fibrillar Collagen ◽  
Type Ii ◽  
Molecular Parameters ◽  
Inhibition Reaction

The reaction of platelets with fibrillar collagen was measured by recording aggregation according to Borns method and by retraction of Ancrod-fibrin clots. These reactions could be completely inhibited by coating the fibrils with stoichiometric amounts of purified antibodies to type I, II or III collagens. The inhibition was specific, i. e. antibodies to type I collagen prevented aggregation by type I collagen but not by type II or III collagen. Comparable amounts ofantibodies to fibrinogen or to serum albumin had no effect on the reaction. The data indicate that platelet aggregation by type I or II collagen fibrils is not due to contamination with type III collagen. The inhibition reaction may be useful for further studies on molecular parameters of the interaction between platelets and collagen fibers.

Hydrogen peroxide-induced degradation of type I collagen fibers of tilapia skin

2014 ◽  
Vol 2 (1-2) ◽  
pp. 41-48 ◽  
Author(s):  
Xiaoling Liu ◽  
Yuanxin Jiang ◽  
Hong He ◽  
Wei Ping
Keyword(s):  
Hydrogen Peroxide ◽  
Type I Collagen ◽  
Collagen Fibers ◽  
Type I

scholarly journals Molecular Mechanism for Connective Tissue Destruction by Dipeptidyl Aminopeptidase IV Produced by the Periodontal Pathogen Porphyromonas gingivalis

2005 ◽  
Vol 73 (5) ◽  
pp. 2655-2664 ◽  
Author(s):  
Yumi Kumagai ◽  
Hisao Yagishita ◽  
Ayako Yajima ◽  
Tatsuya Okamoto ◽  
Kiyoshi Konishi
Keyword(s):  
Connective Tissue ◽  
Molecular Mechanism ◽  
Porphyromonas Gingivalis ◽  
Type I Collagen ◽  
Plasmid Vector ◽  
Periodontal Pathogen ◽  
Matrix Metalloproteinase 2 ◽  
Type I ◽  
Tissue Destruction ◽  
Dipeptidyl Aminopeptidase

ABSTRACT Porphyromonas gingivalis is a pathogen associated with adult periodontitis. It produces dipeptidyl aminopeptidase IV (DPPIV), which may act as a virulence factor by contributing to the degradation of connective tissue. We investigated the molecular mechanism by which DPPIV contributes to the destruction of connective tissue. DPPIV itself did not show gelatinase or collagenase activity toward human type I collagen, but it promoted the activity of the host-derived matrix metalloproteinase 2 (MMP-2) (gelatinase) and MMP-1 (collagenase). DPPIV bound to fibronectin and mediated the adhesion of P. gingivalis to fibronectin. Mutant DPPIV with catalytic Ser mutagenized to Ala (DPPSA) did not accelerate the degradation of collagen and gelatin by MMPs but retained fibronectin-binding activity. The adhesion of human gingival fibroblasts and NIH 3T3 cells to fibronectin was inhibited by DPPIV. Strain 4351ADPPSA exhibited an intermediate level of virulence in mice, between that of the strain expressing wild-type DPPIV (4351ADPP) and that of the strain harboring only the plasmid vector (4351AVEC). It is suggested that both activity promoting the degradation of collagen and gelatin and binding to fibronectin are required for full virulence. These results reveal novel biological functions of DPPIV and suggest a pathological role in the progression of periodontitis.

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