scholarly journals Structure–mechanics relationships of collagen fibrils in the osteogenesis imperfecta mouse model

2015 ◽  
Vol 12 (111) ◽  
pp. 20150701 ◽  
Author(s):  
O. G. Andriotis ◽  
S. W. Chang ◽  
M. Vanleene ◽  
P. H. Howarth ◽  
D. E. Davies ◽  
...  
Keyword(s):  
Mouse Model ◽  
Osteogenesis Imperfecta ◽  
Collagen Fibril ◽  
Bound Water ◽  
Collagen Fibrils ◽  
Collagen Molecule ◽  
Indentation Modulus ◽  
Microscopy Imaging ◽  
Col1a2 Gene ◽  
The Individual

The collagen molecule, which is the building block of collagen fibrils, is a triple helix of two α1(I) chains and one α2(I) chain. However, in the severe mouse model of osteogenesis imperfecta (OIM), deletion of the COL1A2 gene results in the substitution of the α2(I) chain by one α1(I) chain. As this substitution severely impairs the structure and mechanics of collagen-rich tissues at the tissue and organ level, the main aim of this study was to investigate how the structure and mechanics are altered in OIM collagen fibrils. Comparing results from atomic force microscopy imaging and cantilever-based nanoindentation on collagen fibrils from OIM and wild-type (WT) animals, we found a 33% lower indentation modulus in OIM when air-dried (bound water present) and an almost fivefold higher indentation modulus in OIM collagen fibrils when fully hydrated (bound and unbound water present) in phosphate-buffered saline solution (PBS) compared with WT collagen fibrils. These mechanical changes were accompanied by an impaired swelling upon hydration within PBS. Our experimental and atomistic simulation results show how the structure and mechanics are altered at the individual collagen fibril level as a result of collagen gene mutation in OIM. We envisage that the combination of experimental and modelling approaches could allow mechanical phenotyping at the collagen fibril level of virtually any alteration of collagen structure or chemistry.

scholarly journals Marine Polysaccharide-Collagen Coatings on Ti6Al4V Alloy Formed by Self-Assembly

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 68 ◽  
Author(s):  
Karl Norris ◽  
Oksana Mishukova ◽  
Agata Zykwinska ◽  
Sylvia Colliec-Jouault ◽  
Corinne Sinquin ◽  
...  
Keyword(s):  
Self Assembly ◽  
Collagen Fibril ◽  
Hydrothermal Vents ◽  
Sem Analysis ◽  
Collagen Fibrils ◽  
Collagen Molecule ◽  
Biological Characterization ◽  
Collagen Hydrogel ◽  
Biomaterial Surfaces ◽  
Titanium Alloy Ti6al4v

Polysaccharides of marine origin are gaining interest as biomaterial components. Bacteria derived from deep-sea hydrothermal vents can produce sulfated exopolysaccharides (EPS), which can influence cell behavior. The use of such polysaccharides as components of organic, collagen fibril-based coatings on biomaterial surfaces remains unexplored. In this study, collagen fibril coatings enriched with HE800 and GY785 EPS derivatives were deposited on titanium alloy (Ti6Al4V) scaffolds produced by rapid prototyping and subjected to physicochemical and cell biological characterization. Coatings were formed by a self-assembly process whereby polysaccharides were added to acidic collagen molecule solution, followed by neutralization to induced self-assembly of collagen fibrils. Fibril formation resulted in collagen hydrogel formation. Hydrogels formed directly on Ti6Al4V surfaces, and fibrils adsorbed onto the surface. Scanning electron microscopy (SEM) analysis of collagen fibril coatings revealed association of polysaccharides with fibrils. Cell biological characterization revealed good cell adhesion and growth on bare Ti6Al4V surfaces, as well as coatings of collagen fibrils only and collagen fibrils enhanced with HE800 and GY785 EPS derivatives. Hence, the use of both EPS derivatives as coating components is feasible. Further work should focus on cell differentiation.

scholarly journals Longitudinal Microbiome Analysis in a Dextran Sulfate Sodium-Induced Colitis Mouse Model

2021 ◽  
Vol 9 (2) ◽  
pp. 370
Author(s):  
Hyunjoon Park ◽  
Soyoung Yeo ◽  
Seokwon Kang ◽  
Chul Sung Huh
Keyword(s):  
Mouse Model ◽  
Dextran Sulfate ◽  
Dextran Sulfate Sodium ◽  
Intestinal Bleeding ◽  
Cross Sectional ◽  
Microbiome Analysis ◽  
Inflammatory Bowel ◽  
Factor Design ◽  
The Individual

The role of the gut microbiota in the pathogenesis of inflammatory bowel disease (IBD) has been in focus for decades. Although metagenomic observations in patients/animal colitis models have been attempted, the microbiome results were still indefinite and broad taxonomic presumptions were made due to the cross-sectional studies. Herein, we conducted a longitudinal microbiome analysis in a dextran sulfate sodium (DSS)-induced colitis mouse model with a two-factor design based on serial DSS dose (0, 1, 2, and 3%) and duration for 12 days, and four mice from each group were sacrificed at two-day intervals. During the colitis development, a transition of the cecal microbial diversity from the normal state to dysbiosis and dynamic changes of the populations were observed. We identified genera that significantly induced or depleted depending on DSS exposure, and confirmed the correlations of the individual taxa to the colitis severity indicated by inflammatory biomarkers (intestinal bleeding and neutrophil-derived indicators). Of note, each taxonomic population showed its own susceptibility to the changing colitis status. Our findings suggest that an understanding of the individual susceptibility to colitis conditions may contribute to identifying the role of the gut microbes in the pathogenesis of IBD.

scholarly journals Ultrastructural Imaging of Collagen Fibrils in Mouse Model of Abdominal Aortic Aneurysm

2016 ◽  
Vol 22 (S3) ◽  
pp. 1196-1197 ◽  
Author(s):  
Jeffrey R Tonniges ◽  
Ben Albert ◽  
Edward Calomeni ◽  
Chetan Hans ◽  
Gunjan Agarwal
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Mouse Model ◽  
Collagen Fibrils ◽  
Abdominal Aortic

Growth and development of collagen fibrils in immature tissues from rat and sheep

1981 ◽  
Vol 212 (1186) ◽  
pp. 85-92 ◽  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Collagen Fibril ◽  
Growth And Development ◽  
Collagen Fibrils ◽  
Diameter Distribution ◽  
Rat Tissues ◽  
Transmission Electron ◽  
The Mean ◽  
Fibril Diameter

The collagen fibril diameter distribution of four immature tissues from both rat and sheep have been determined from transverse sections observed in the transmission electron microscope. In many instances before birth, the form of the distribution for the tissues is both unimodal and sharp and the mean diameters of the distributions lie close to a multiple of 80 Å. For some tissues, the collagen fibril diameter distributions may be resolved into a number of components, each of which represents a population of fibrils with a diameter close to a multiple of 80 Å (8 nm). These data confirm and extend previous observations by the authors that small collagen fibrils all have diameters that are multiples of about 80 Å and that the fibril growth occurs by the accretion of 80 Å units. The form of the collagen fibril diameter distribution at birth is broad for the sheep tissues but narrow for the rat tissues, thus confirming that the range of fibril diameters at this stage of life reflects the differing degree of development of precocious and altricious animals.

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