Introduction: The composite nature of bone as a material governs its structure and mechanical behavior. How the collagenous matrix mineralizes, in terms of both mineral deposition and structure of the mineral crystals, is highly interesting when trying to elucidate the complex structural changes that occur during bone growth and maturation. We have previously looked at mineral deposition and structural evolution of the collagenous matrix, linking both to changes in mechanics. The purpose of this study was to provide specific information on changes in crystal size and organization as a function of growth and maturation.
Materials and Methods: Using micro-computed tomography (µCT) and micro-focused scanning small-angle X-ray scattering (SAXS) we investigated cortical bone in two orthogonal directions relative to the long axis of the humeri of New Zealand White rabbits spanning from new-born to 6-months of age. We also investigated the changes with tissue age by looking at radial profiles of osteonal structures in the 6-months old rabbits. The findings were compared to our previous compositional, structural and mechanical data on the same sample cohort.
Results: µCT showed a continuous mineral deposition up until 3-months of age, whilst the SAXS data showed an increase in both crystal thickness and degree of orientation up until 6-months of age. The osteonal profiles showed no statistically significant changes in crystal thickness.
Conclusions: Comparison to previously collected mechanical data suggests that changes are not only explained by amount of mineral in the tissue but also by the crystal dimensions.
|1994||Crofts RD, Boyce TM, Bloebaum RD. Aging changes in osteon mineralization in the human femoral neck. Bone. March–April 1994;15(2):147-152.|
|1987||Legros R, Balmain N, Bonel G. Age-related changes in mineral of rat and bovine cortical bone. Calcif Tiss Int. September 1987;41(3):137-144.|
|1952||Amprino R, Engström A. Studies on x-ray absorption and diffraction of bone tissue. Acta Anat. 1952;15(1-2):1-22.|
|2008||Fuchs RK, Allen MR, Ruppel ME, Diab T, Phipps RJ, Miller LM, Burr DB. In situ examination of the time-course for secondary mineralization of Haversian bone using synchrotron Fourier transform infrared microspectroscopy. Matrix Biol. January 2008;27(1):34-41.|
|2016||Turunen MJ, Kaspersen JD, Olsson U, Guizar-Sicairos M, Bech M, Schaff F, Tägil M, Jurvelin JS, Isaksson H. Bone mineral crystal size and organization vary across mature rat bone cortex. J Struct Biol. September 2016;195(3):337-344.|
|2010||Donnelly E, Boskey AL, Baker SP, van der Meulen MCH. Effects of tissue age on bone tissue material compositionand nanomechanical properties in the rat cortex. J Biomed Mater Res. March 1, 2010;A92(3):1048-1056.|
|1991||Fratzl P, Fratzl-Zelman N, Klaushofer K, Vogl G, Koller K. Nucleation and growth of mineral crystals in bone studied by small-angle X-ray scattering. Calcif Tiss Int. June 1991;48(6):407-413.|
|2015||Stock SR. The mineral–collagen interface in bone. Calcif Tiss Int. September 2015;97(3):262-280.|
|2010||Isaksson H, Malkiewicz M, Nowak R, Helminen HJ, Jurvelin JS. Rabbit cortical bone tissue increases its elastic stiffness but becomes less viscoelastic with age. Bone. December 2010;47(6):1030-1038.|
|1996||Paschalis EP, DiCarlo E, Betts F, Sherman P, Mendelsohn R, Boskey AL. FTIR microspectroscopic analysis of human osteonal bone. Calcif Tiss Int. December 1996;59(6):480-487.|
|1996||Fratzl P, Schreiber S, Klaushofer K. Bone mineralization as studied by small-angle x-ray scattering. Connect Tissue Res. 1996;34(4):247-254.|
|2014||Reznikov N, Shahar R, Weiner S. Bone hierarchical structure in three dimensions. Acta Biomater. September 2014;10(8):3815-3826.|
|2011||Burket J, Gourion-Arsiquaud S, Havill LM, Baker SP, Boskey AL, van der Meulen MCH. Microstructure and nanomechanical properties in osteons relate to tissue and animal age. J Biomech. January 11, 2011;44(2):277-284.|
|2018||Reznikov N, Bilton M, Lari L, Stevens MM, Kröger R. Fractal-like hierarchical organization of bone begins at the nanoscale. Science. May 4, 2018;360(6388):eaao2189.|
|2020||Fraulob M, Le Cann S, Voumard B, Yasui H, Yano K, Vayron R, Matsukawa M, Zysset P, Haïat G. Multimodal evaluation of the spatiotemporal variations of periprosthetic bone properties. J Biomech Eng. December 2020;142(12):121014.|
|2021||Törnquist E. Bone Structure Characterisation Using Neutron Scattering Techniques [PhD thesis]. Lund, Sweden: Lund University; 2021.|