TY - JOUR
T1 - Deproteinized young bone reveals a continuous mineral phase and its contribution to mechanical properties with age
AU - Pang, Siyuan
AU - Su, Frances Y.
AU - McKittrick, Joanna
AU - Jasiuk, Iwona
N1 - Funding Information:
This research was done at the Materials Research Laboratory and the Beckman Institute at the University of Illinois. We acknowledge funding from the National Science Foundation, Biomaterials program, grants DMR-1507978 and DMR-1507169, and Mechanics of Materials and Structures program grant MOMS-1926353. We would also like to thank Dr. Shaochen Chen, Henry Hwang, and Claire Yu for donating the 16-week porcine bones for this study (NIH R01EB021857). We would also like to thank Dr. Henry Schwarcz for his valuable comments and ideas, which made this work stronger.
Funding Information:
This research was done at the Materials Research Laboratory and the Beckman Institute at the University of Illinois. We acknowledge funding from the National Science Foundation , Biomaterials program, grants DMR-1507978 and DMR-1507169, and Mechanics of Materials and Structures program grant MOMS-1926353. We would also like to thank Dr. Shaochen Chen, Henry Hwang, and Claire Yu for donating the 16-week porcine bones for this study (NIH R01EB021857). We would also like to thank Dr. Henry Schwarcz for his valuable comments and ideas, which made this work stronger.
Publisher Copyright:
© 2020
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Bone is composed of mineral (apatite crystals) phase, organic (proteins, mainly collagen, and other organics) phase, and water at the nanoscale. Mineral contributes to elastic modulus and strength while organics and water give bone its toughness. Changes in the mineral composition and arrangement with age during development, and the resulting mechanical properties, are of high scientific and clinical interests. The mineral phase can be studied by removing the organic phase from bone using sodium hypochlorite (NaClO). This process is called deproteinization (DP). In this paper, four age groups (3-week, 4-week, 16-week, and 24-week) were compared in both untreated and DP bone states. We find that the deproteinized bone samples from all these age groups are self-standing. Thus, the mineral phase forms a continuous structure, even in the 3-week bone. Micro-computed tomography imaging displays a significant porosity decrease with the increase in age. Raman spectroscopy reveals increases in both the carbonate-to-phosphate ratio and the mineral crystallinity with age. Compression test results show that the elastic modulus and strength of the mineral phase alone are positively related to age. The elastic modulus of DP bone is less affected by age than that of the untreated bone. Overall, the mechanical properties of the mineral phase increase with age due to a decrease in porosity and an increase in the mineral content.
AB - Bone is composed of mineral (apatite crystals) phase, organic (proteins, mainly collagen, and other organics) phase, and water at the nanoscale. Mineral contributes to elastic modulus and strength while organics and water give bone its toughness. Changes in the mineral composition and arrangement with age during development, and the resulting mechanical properties, are of high scientific and clinical interests. The mineral phase can be studied by removing the organic phase from bone using sodium hypochlorite (NaClO). This process is called deproteinization (DP). In this paper, four age groups (3-week, 4-week, 16-week, and 24-week) were compared in both untreated and DP bone states. We find that the deproteinized bone samples from all these age groups are self-standing. Thus, the mineral phase forms a continuous structure, even in the 3-week bone. Micro-computed tomography imaging displays a significant porosity decrease with the increase in age. Raman spectroscopy reveals increases in both the carbonate-to-phosphate ratio and the mineral crystallinity with age. Compression test results show that the elastic modulus and strength of the mineral phase alone are positively related to age. The elastic modulus of DP bone is less affected by age than that of the untreated bone. Overall, the mechanical properties of the mineral phase increase with age due to a decrease in porosity and an increase in the mineral content.
KW - Age effect
KW - Composition
KW - Continuous mineral phase
KW - Deproteinization
KW - Mechanical properties
KW - Young bone
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U2 - 10.1016/j.jmrt.2020.11.001
DO - 10.1016/j.jmrt.2020.11.001
M3 - Article
AN - SCOPUS:85101846451
SN - 2238-7854
VL - 9
SP - 15421
EP - 15432
JO - Journal of Materials Research and Technology
JF - Journal of Materials Research and Technology
IS - 6
ER -