Study of Nano-Mechanics of Collagen I Triple-helices by Computerized Processing of AFM Images

2012 ◽  
Vol 1422 ◽  
Author(s):  
Arkady Bitler ◽  
Emanuel Perugia ◽  
Sidney R. Cohen
Keyword(s):  
Mechanical Properties ◽  
Persistence Length ◽  
Collagen Type I ◽  
Segment Length ◽  
Type I ◽  
Ambient Conditions ◽  
Atomic Force ◽  
Collagen Molecules ◽  
High Resolution Images ◽  
Triple Helices

ABSTRACTWe used atomic force microscope (AFM) to acquire high-resolution images of collagen type I triple-helices under ambient conditions in tapping mode. Angles between consecutive fixed-length segments were measured and analyzed to yield persistence length and elastic constant. Changing the segment length allowed exploring the mechanics at various scales. Understanding the mechanical properties of collagen molecules could serve to elucidate mechanisms of complex mechanical properties of interest in nanomedicine and nanotechnology.

scholarly journals A Reconsideration of the Effect of Procyanidin on the Assembly of Collagen Type I

2018 ◽  
Author(s):  
Y. Wang ◽  
L. Jin
Keyword(s):  
Collagen Type I ◽  
Type I ◽  
Cd Spectra ◽  
Effect Mechanism ◽  
Atomic Force ◽  
Before And After ◽  
Collagen Molecules ◽  
Exact Effect ◽  
Positive Effect ◽  
Thermal Stability Of

ABSTRACTIn order to elucidating the exact effect mechanism of polyphenols on the assembly of collagen, the assembled architectures of collagen treated with different amounts of procyanidin (PA) were investigated in details. The assembled morphologies of collagen were greatly influenced by the content of PA according to atomic force microcopy (AFM) images. When the content of PA was more than 20% (w/w), the fibrillar morphologies were substituted by globular aggregates, which were driven by the intense hydrogen bonding action originating from PA. While the formation of the non-fibrous aggregates was due to the coiling and entangling of flexible collagen molecules rather than their gelatinization based on the appearance of typical adsorption peaks at 222nm and 197nm on circular dichroism (CD) spectra. After being crosslinked by glutaraldehyde (GA), not only the diameters but also the lengths of fibrils increased. Unfortunately, the fibrillogenesis was still inhibited when the collagen suffered from 20% PA firstly and then 4% GA. Conversely, the fibrous morphologies of the fibrils stabilized by 4% GA and then underwent 20% PA maintained well, in spite of accompanying with grievous intertwining. This difference was derived from the change of flexibilities of collagen before and after being crosslinked by GA. Additionally, the differential scanning calorimeter (DSC) analysis confirmed the PA had no positive effect on the improvement of thermal stability of hydrous collagen, whereas the denaturation temperature of hydrated collagen stabilized by 4% GA increased from 40 °C to 80 °C.

scholarly journals Influence of fibrillin-1 genotype on aortic stiffness in men: a note of caution

2006 ◽  
Vol 100 (4) ◽  
pp. 1431-1432
Author(s):  
Yasmin ◽  
Ian B. Wilkinson ◽  
Kevin M. O’Shaughnessy
Keyword(s):  
Mechanical Properties ◽  
Pulse Pressure ◽  
Aortic Stiffness ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Increased Risk ◽  
Fibrillin 1 ◽  
Echo Tracking

Aortic stiffness is a predictor of cardiovascular mortality. The mechanical properties of the arterial wall depend on the connective tissue framework, with variation in fibrillin-1 and collagen I genes being associated with aortic stiffness and/or pulse pressure elevation. The aim of this study was to investigate whether variation in fibrillin-1 genotype was associated with aortic stiffness in men. The mechanical properties of the abdominal aorta of 79 healthy men (range 28–81 yr) were investigated by ultrasonographic phase-locked echo tracking. Fibrillin-1 genotype, characterized by the variable tandem repeat in intron 28, and collagen type I alpha 1 genotype characterized by the 2,064 G\?\T polymorphism, were determined by using DNA from peripheral blood cells. Three common fibrillin-1 genotypes, 2-2, 2-3, and 2-4, were observed in 50 (64%), 10 (13%), and 11 (14%) of the men, respectively. Those of 2-3 genotype had higher pressure strain elastic modulus and aortic stiffness compared with men of 2-2 or 2-4 genotype ( P = 0.005). Pulse pressure also was increased in the 2-3 genotype ( P = 0.04). There was no significant association between type 1 collagen genotype and aortic stiffness in this cohort. In conclusion, the fibrillin-1 2-3 genotype in men was associated with increased aortic stiffness and pulse pressure, indicative of an increased risk for cardiovascular disease.

Enhancement by Heparin of Affinity between Cold-Insoluble Globulin and Native Collagen Type III

1979 ◽  
Author(s):  
H. Hörmann ◽  
F. Jilek
Keyword(s):  
Collagen Type ◽  
Weight Ratio ◽  
Collagen Type I ◽  
Type I ◽  
Collagen Type Iii ◽  
Type Iii ◽  
Soluble Collagen ◽  
Native Collagen ◽  
Collagen Molecules ◽  
Cold Insoluble Globulin

Affinity between collagen and cold-insoluble globulin was measured by complexing soluble 125-J labelled collagen preparations with the globulin. Precipitates containing considerable activity were formed at 4°C and 22°C by denatured soluble collagen, type I and type III, but only little by native soluble collagen. The precipitation of native collagen, type III, by cold-insoluble globulin was enhanced by heparin. Under optimal conditions at a weight ratio or heparin and cold-insoluble globulin of about 1:1 up to 60% of the collagen applied was insolubilized. Native collagen, type I, was complexed far less effectively even in presence of heparin. Electronmicroscopic and precipitation experiments using 125-J labelled cold-insoluble globulin indicated that heparin might induce a partial conversion of cold-insoluble globulin to a fibrillar derivative which exhibited improved binding properties for the rod-like native collagen molecules. – Supported by Deutsche Forschungsgemeinschaft, Project Ho 740/1.

scholarly journals Atomic Force Microscopy for Collagen-Based Nanobiomaterials

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Andreas Stylianou
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Collagen Type I ◽  
Quantitative Information ◽  
Fibrillar Structure ◽  
Type I ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range

Novel nanobiomaterials are increasingly gaining ground in bioengineering research. Among the numerous biomaterials, collagen-nanobiomaterials, such as collagen thin films, are of great interest since they present a wide range of applications in the fields of biomaterials, tissue engineering, and biomedicine. Collagen type I is the most abundant protein within extracellular matrix and, due to its unique characteristics, is widely used as biomaterial. A thorough characterization of the structure and properties of nanomaterials can be achieved by Atomic Force Microscopy (AFM). AFM is a very powerful tool which can be used to obtain qualitative or quantitative information without destroying the collagen fibrillar structure. This mini review covers issues related to the use of AFM for studying the structure and mechanical properties of collagen-based nanobiomaterials, collagen-substrate interactions during the formation of collagen thin films, collagen-cells interactions, and the collagen-optical radiation interactions.

Mechanical properties of single electrospun collagen type I fibers

Biomaterials ◽  
2008 ◽  
Vol 29 (8) ◽  
pp. 955-962 ◽  
Author(s):  
Lanti Yang ◽  
Carel F.C. Fitié ◽  
Kees O. van der Werf ◽  
Martin L. Bennink ◽  
Pieter J. Dijkstra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Type I Fibers

scholarly journals The role of collagen in extralobar pulmonary artery stiffening in response to hypoxia-induced pulmonary hypertension

2010 ◽  
Vol 299 (6) ◽  
pp. H1823-H1831 ◽  
Author(s):  
Chen Yen Ooi ◽  
Zhijie Wang ◽  
Diana M. Tabima ◽  
Jens C. Eickhoff ◽  
Naomi C. Chesler
Keyword(s):  
Mechanical Properties ◽  
Pulmonary Hypertension ◽  
Elastic Modulus ◽  
Pulmonary Artery ◽  
Chronic Hypoxia ◽  
Collagen Type ◽  
High Strain ◽  
Collagen Type I ◽  
Mouse Strains ◽  
Type I

Hypoxic pulmonary hypertension (HPH) causes extralobar pulmonary artery (PA) stiffening, which potentially impairs right ventricular systolic function. Changes in the extracellular matrix proteins collagen and elastin have been suggested to contribute to this arterial stiffening. We hypothesized that vascular collagen accumulation is a major cause of extralobar PA stiffening in HPH and tested our hypothesis with transgenic mice that synthesize collagen type I resistant to collagenase degradation (Col1a1R/R). These mice and littermate controls that have normal collagen degradation (Col1a1+/+) were exposed to hypoxia for 10 days; some were allowed to recover for 32 days. In vivo PA pressure and isolated PA mechanical properties and collagen and elastin content were measured for all groups. Vasoactive studies were also performed with U-46619, Y-27632, or calcium- and magnesium-free medium. Pulmonary hypertension occurred in both mouse strains due to chronic hypoxia and resolved with recovery. HPH caused significant PA mechanical changes in both mouse strains: circumferential stretch decreased, and mid-to-high-strain circumferential elastic modulus increased ( P < 0.05 for both). Impaired collagen type I degradation prevented a return to baseline mechanical properties with recovery and, in fact, led to an increase in the low and mid-to-high-strain moduli compared with hypoxia ( P < 0.05 for both). Significant changes in collagen content were found, which tended to follow changes in mid-to-high-strain elastic modulus. No significant changes in elastin content or vasoactivity were observed. Our results demonstrate that collagen content is important to extralobar PA stiffening caused by chronic hypoxia.

Influence of fibrillin-1 genotype on the aortic stiffness in men

2005 ◽  
Vol 99 (3) ◽  
pp. 1036-1040 ◽  
Author(s):  
J. T. Powell ◽  
R. J. Turner ◽  
M. Sian ◽  
R. Debasso ◽  
T. Länne
Keyword(s):  
Mechanical Properties ◽  
Pulse Pressure ◽  
Aortic Stiffness ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Increased Risk ◽  
Fibrillin 1 ◽  
Echo Tracking

Aortic stiffness is a predictor of cardiovascular mortality. The mechanical properties of the arterial wall depend on the connective tissue framework, with variation in fibrillin-1 and collagen I genes being associated with aortic stiffness and/or pulse pressure elevation. The aim of this study was to investigate whether variation in fibrillin-1 genotype was associated with aortic stiffness in men. The mechanical properties of the abdominal aorta of 79 healthy men (range 28–81 yr) were investigated by ultrasonographic phase-locked echo tracking. Fibrillin-1 genotype, characterized by the variable tandem repeat in intron 28, and collagen type I alpha 1 genotype characterized by the 2,064 G>T polymorphism, were determined by using DNA from peripheral blood cells. Three common fibrillin-1 genotypes, 2-2, 2-3, and 2-4, were observed in 50 (64%), 10 (13%), and 11 (14%) of the men, respectively. Those of 2-3 genotype had higher pressure strain elastic modulus and aortic stiffness compared with men of 2-2 or 2-4 genotype ( P = 0.005). Pulse pressure also was increased in the 2-3 genotype ( P = 0.04). There was no significant association between type 1 collagen genotype and aortic stiffness in this cohort. In conclusion, the fibrillin-1 2-3 genotype in men was associated with increased aortic stiffness and pulse pressure, indicative of an increased risk for cardiovascular disease.

Effect of YOYO-1 on the mechanical properties of DNA

Soft Matter ◽  
2014 ◽  
Vol 10 (48) ◽  
pp. 9721-9728 ◽  
Author(s):  
Binu Kundukad ◽  
Jie Yan ◽  
Patrick S. Doyle
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Persistence Length ◽  
Contour Length ◽  
Force Microscopy ◽  
Atomic Force

Atomic force microscopy studies show that binding of YOYO-1 to DNA increases the contour length of DNA without affecting the persistence length due to the underwinding of DNA.

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