Effect of age on rat bone solubility and crystallinity

Area of Science:

• Biomineralization
• Bone Physiology
• Materials Science

Background:

• Biominerals like bone and enamel exist in a metastable equilibrium solubility (MES) state.
• These minerals comprise domains with individual MES, influenced by crystallinity.
• Solubility decreases as crystallinity increases.

Purpose of the Study:

• To investigate the impact of aging on the metastable equilibrium solubility (MES) and crystallinity of rat bone mineral.
• To compare MES distributions and crystallinity in bone from rats of varying ages (1-25 months).

Main Methods:

• Bone mineral samples were prepared via protein extraction using hydrazine and alcohol solutions.
• MES distributions were determined by exposing samples to acetate buffers with varying calcium and phosphate concentrations.
• Crystallinity was assessed using X-ray powder diffraction, measuring the full width at half maximum (FWHM) of the 002 reflection.

Main Results:

• Older bone mineral exhibited lower solubility and higher crystallinity compared to younger bone mineral.
• The distribution of solubility shifted from narrow to broader with increasing age.
• An inverse-linear correlation between crystallinity and mean MES was observed across all age groups.

Conclusions:

• Age significantly influences bone mineral's metastable equilibrium solubility and crystallinity.
• Increased bone crystallinity with age correlates with decreased solubility, consistent with established biomineral properties.
• Age-related changes in bone mineral structure affect its solubility characteristics.