Bone toughening through stress-induced non-collagenous protein denaturation
- 330 Downloads
Bone toughness emerges from the interaction of several multiscale toughening mechanisms. Recently, the formation of nanoscale dilatational bands and hence the accumulation of submicron diffuse damage were suggested as an important energy dissipation processes in bone. However, a detailed mechanistic understanding of the effect of this submicron toughening mechanism across multiple scales is lacking. Here, we propose a new three-dimensional ultrastructure volume element model showing the formation of nanoscale dilatational bands based on stress-induced non-collagenous protein denaturation and quantify the total energy released through this mechanism in the vicinity of a propagating crack. Under tensile deformation, large hydrostatic stress develops at the nanoscale as a result of local confinement. This tensile hydrostatic stress supports the denaturation of non-collagenous proteins at organic–inorganic interfaces, which leads to energy dissipation. Our model provides new fundamental understanding of the mechanism of dilatational bands formation and its contribution to bone toughness.
KeywordsBone Mineralized collagen fibril Finite element modeling Non-collagenous proteins Fracture toughness
This study was financially supported by the US National Science Foundation (NSF) through Grant CMMI 1363526 and the National Institute of Health (NIH) through Grant AR49635.
Compliance with ethical standard
Conflict of interest
The authors declare that they have no conflict of interest.
- Hall BK (2015) Chapter 24—Osteoblast and osteocyte diversity and osteogenesis in vitro. Bones and cartilage, 2nd edn. Academic, San Diego, pp 401–413Google Scholar
- Hodge AJ, Petruska JA (1962) Some recent results on the electron microscopy of tropocollagen structures. In: Breese SS Jr (ed) Proc. of the fifth Internat. Congr. for Electron Microscopy, vol 2. Academic, New York, p QQ-1Google Scholar
- Karunaratne A, Esapa CR, Hiller J et al (2012) Significant deterioration in nanomechanical quality occurs through incomplete extrafibrillar mineralization in rachitic bone: Evidence from in-situ synchrotron X-ray scattering and backscattered electron imaging. J Bone Miner Res 27:876–890. https://doi.org/10.1002/jbmr.1495 CrossRefGoogle Scholar
- Peroos S, Du Z, de Leeuw NH (2006) A computer modelling study of the uptake, structure and distribution of carbonate defects in hydroxy-apatite. Biomaterials 27:2150–2161. https://doi.org/10.1016/j.biomaterials.2005.09.025 CrossRefGoogle Scholar
- Poundarik AA, Gundberg CM, Vashishth D (2011) Non-collageneous proteins influence bone crystal size and morphology: a SAXS study. In: 2011 IEEE 37th annual northeast bioengineering conference (NEBEC), Troy, pp 1–2. https://doi.org/10.1109/nebc.2011.5778671
- Poundarik AA, Diab T, Sroga GE et al (2012) Dilatational band formation in bone. Proc Natl Acad Sci. https://doi.org/10.1073/pnas.1201513109/-/dcsupplemental Google Scholar
- Zimmermann EA, Gludovatz B, Schaible E et al (2014) Fracture resistance of human cortical bone across multiple length-scales at physiological strain rates. Biomaterials 35:5472–5481. https://doi.org/10.1016/j.biomaterials.2014.03.066 CrossRefGoogle Scholar