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Multiscale alterations in bone matrix quality increased fragility in steroid induced osteoporosis.

Karunaratne A, Xi L, Bentley L, Sykes D, Boyde A, Esapa CT, Terrill NJ, Brown SD, Cox RD, Thakker RV, Gupta HS - Bone (2015)

Bottom Line: We measure the deformation of the mineralized collagen fibrils, and the nano-mechanical parameters including effective fibril modulus and fibril to tissue strain ratio.A significant reduction (51%) of fibril modulus was found in Crh(-120/+) mice.We also find a much larger fibril strain/tissue strain ratio in Crh(-120/+) mice (~1.5) compared to the wild-type mice (~0.5), indicative of a lowered mechanical competence at the nanoscale.

View Article: PubMed Central - PubMed

Affiliation: Queen Mary University of London, School of Engineering and Material Science, Mile End Road, London E1 4NS, UK. Electronic address: a.karunaratne@imperial.ac.uk.

No MeSH data available.


Related in: MedlinePlus

Macro mechanical testing results. (A) Stress vs. measured tissue strain % for WT (n = 4/filled symbols) and Crh− 120/+ (n = 6/open symbols) mice for each sample. Solid lines are average regression lines for wild-type (black) and Crh− 120/+ (grey). Average tissue modulus σ/εT showing in inset. (B) Maximum stress and (C) maximum tissue strain plotted for WT (black) and Crh− 120/+ (grey) mice. Error bars are standard deviations. Student's t tests were used to compare elastic moduli, maximum stress and maximum strain between wild-type and Crh− 120/+ mice. Pairwise brackets denote statistical significance (*p < 0.05, ns = not significant).
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f0025: Macro mechanical testing results. (A) Stress vs. measured tissue strain % for WT (n = 4/filled symbols) and Crh− 120/+ (n = 6/open symbols) mice for each sample. Solid lines are average regression lines for wild-type (black) and Crh− 120/+ (grey). Average tissue modulus σ/εT showing in inset. (B) Maximum stress and (C) maximum tissue strain plotted for WT (black) and Crh− 120/+ (grey) mice. Error bars are standard deviations. Student's t tests were used to compare elastic moduli, maximum stress and maximum strain between wild-type and Crh− 120/+ mice. Pairwise brackets denote statistical significance (*p < 0.05, ns = not significant).

Mentions: Tissue level and fibrillar and mechanics of cortical bone from femoral mid-diaphyses of 26 week old WT (n = 4) and Crh− 120/+ (n = 6) mice were measured using in situ micro mechanical tensile testing combined with microfocus SAXD. Porosity-corrected stress versus tissue strain was plotted (Fig. 5A) as a function of genotype. Tissue level elastic moduli are significantly (p < 0.05) lower in Crh− 120/+ mice compared to WT mice (Fig. 5A inset). Average yield stress (Fig. 5B) of the WT mice (28.2 MPa ± 7.1 S.D.) is significantly larger compared to Crh− 120/+ mice (16.2 MPa ± 7.3 S.D.). Tissue yield strain of Crh− 120/+ mice was not significantly different (p > 0.05) from WT mice (Fig. 5C).


Multiscale alterations in bone matrix quality increased fragility in steroid induced osteoporosis.

Karunaratne A, Xi L, Bentley L, Sykes D, Boyde A, Esapa CT, Terrill NJ, Brown SD, Cox RD, Thakker RV, Gupta HS - Bone (2015)

Macro mechanical testing results. (A) Stress vs. measured tissue strain % for WT (n = 4/filled symbols) and Crh− 120/+ (n = 6/open symbols) mice for each sample. Solid lines are average regression lines for wild-type (black) and Crh− 120/+ (grey). Average tissue modulus σ/εT showing in inset. (B) Maximum stress and (C) maximum tissue strain plotted for WT (black) and Crh− 120/+ (grey) mice. Error bars are standard deviations. Student's t tests were used to compare elastic moduli, maximum stress and maximum strain between wild-type and Crh− 120/+ mice. Pairwise brackets denote statistical significance (*p < 0.05, ns = not significant).
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4764652&req=5

f0025: Macro mechanical testing results. (A) Stress vs. measured tissue strain % for WT (n = 4/filled symbols) and Crh− 120/+ (n = 6/open symbols) mice for each sample. Solid lines are average regression lines for wild-type (black) and Crh− 120/+ (grey). Average tissue modulus σ/εT showing in inset. (B) Maximum stress and (C) maximum tissue strain plotted for WT (black) and Crh− 120/+ (grey) mice. Error bars are standard deviations. Student's t tests were used to compare elastic moduli, maximum stress and maximum strain between wild-type and Crh− 120/+ mice. Pairwise brackets denote statistical significance (*p < 0.05, ns = not significant).
Mentions: Tissue level and fibrillar and mechanics of cortical bone from femoral mid-diaphyses of 26 week old WT (n = 4) and Crh− 120/+ (n = 6) mice were measured using in situ micro mechanical tensile testing combined with microfocus SAXD. Porosity-corrected stress versus tissue strain was plotted (Fig. 5A) as a function of genotype. Tissue level elastic moduli are significantly (p < 0.05) lower in Crh− 120/+ mice compared to WT mice (Fig. 5A inset). Average yield stress (Fig. 5B) of the WT mice (28.2 MPa ± 7.1 S.D.) is significantly larger compared to Crh− 120/+ mice (16.2 MPa ± 7.3 S.D.). Tissue yield strain of Crh− 120/+ mice was not significantly different (p > 0.05) from WT mice (Fig. 5C).

Bottom Line: We measure the deformation of the mineralized collagen fibrils, and the nano-mechanical parameters including effective fibril modulus and fibril to tissue strain ratio.A significant reduction (51%) of fibril modulus was found in Crh(-120/+) mice.We also find a much larger fibril strain/tissue strain ratio in Crh(-120/+) mice (~1.5) compared to the wild-type mice (~0.5), indicative of a lowered mechanical competence at the nanoscale.

View Article: PubMed Central - PubMed

Affiliation: Queen Mary University of London, School of Engineering and Material Science, Mile End Road, London E1 4NS, UK. Electronic address: a.karunaratne@imperial.ac.uk.

No MeSH data available.


Related in: MedlinePlus