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Collagen and bone viscoelasticity: a dynamic mechanical analysis.

Junro Yamashita·Xiaoe Li·Benjamin R Furman·H Ralph Rawls·Xiaodu Wang·C Mauli Agrawal
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Abstract

The purpose of this study was to explore the effects of changes in Type I collagen on the viscoelasticity of bone. Bone coupons were heated at either 100 or 200 degrees C to induce the thermal denaturation of Type I collagen. Half of these specimens were rehydrated after heat treatment; the other half were tested in a dry condition. The degree of denatured collagen (DC%) was analyzed by a selective digestion technique with the use of alpha-chymotrypsin. Isothermal (37 degrees C) and variable temperature tests (scans from 35 to 200 degrees C) were performed with the use of a dynamic mechanical analyzer to evaluate changes in bone viscoelastic properties as a function of collagen damage, specifically, changes in the loss factor (tan delta) and storage modulus (E') were assessed. Significant collagen denaturation occurred only when bone was heated at 200 degrees C irrespective of the hydration condition. Also, DC% did not show a significant effect on tan delta. However, higher values of tan delta were observed in wet samples compared to dry specimens. The temperature-scan tests revealed that the hydration condition, but not DC%, significantly affected the behavior of tan delta. However, E' was not strongly influenced either by DC% or by water content. These results suggest that at a constant frequency the denaturation of collagen triple-helical molecules may have few effects on the viscoelasticity of bone, but moisture may play a prominent role in determining this property.

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Biomechanical PhenomenaBody WaterBone and BonesChymotrypsinCollagenDesiccationElasticityHot TemperatureHumansProtein DenaturationStress, MechanicalViscosityJournal Article

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Junro Yamashita, Xiaoe Li, Benjamin R Furman, H Ralph Rawls, Xiaodu Wang, C Mauli Agrawal. 2002. Collagen and bone viscoelasticity: a dynamic mechanical analysis.. https://doi.org/10.1002/jbm.10086

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