Bone hydration: How we can evaluate it, what can it tell us, and is it an effective therapeutic target?

Abstract

Water constitutes roughly a quarter of the cortical bone by volume yet can greatly influence mechanical properties and tissue quality. There is a growing appreciation for how water can dynamically change due to age, disease, and treatment. A key emerging area related to bone mechanical and tissue properties lies in differentiating the role of water in its four different compartments, including free/pore water, water loosely bound at the collagen/mineral interfaces, water tightly bound within collagen triple helices, and structural water within the mineral. This review summarizes our current knowledge of bone water across the four functional compartments and discusses how alterations in each compartment relate to mechanical changes. It provides an overview on the advent of- and improvements to- imaging and spectroscopic techniques able to probe nano-and molecular scales of bone water. These technical advances have led to an emerging understanding of how bone water changes in various conditions, of which aging, chronic kidney disease, diabetes, osteoporosis, and osteogenesis imperfecta are reviewed. Finally, it summarizes work focused on therapeutically targeting water to improve mechanical properties.

Bioresorbable Chitosan-Based Bone Regeneration Scaffold Using Various Bioceramics and the Alteration of Photoinitiator Concentration in an Extended UV Photocrosslinking Reaction

“…Meanwhile, the EWC for the scaffolds with different BP contents were 63.61 ± 0.43 (CS/HAp/5 µL BP), 64.60 ± 0.5 (CS/HAp/10 µL BP) and 64.47 ± 0.08 (CS/HAp/20 µL BP), indicating that their swelling ability was around a similar level despite the varied photoinitiator amount. While the EWC of human bone is about 15–25%, this shows the importance of water in bones since it is the main factor affecting the mechanical behaviour of the bones [ 55 , 56 ]. As such, a lower EWC would be desirable.…”

Terahertz refractive phenotype of living cells

“…To this end, two states of mesenchymal stem cells (MSCs) during osteogenic differentiation were choose for the investigation. The osteogenic differentiation of MSCs led to successively form mineralization of bone matrix ( Khezri et al, 2021 ), showing an intense alizarin red staining ( Figure 3A inset; Supplementary Figure S5 ), in which hydration plays a vital structuring role across the bone hierarchy ( Surowiec et al, 2022 ). As shown in Figure 3 , the refractive index of osteogenic differentiated MSCs is smaller than that of undifferentiated ones at the measured terahertz frequency (from .4–1.8 THz).…”

1H‐13C cross‐polarization kinetics to probe hydration‐dependent organic components of bone extracellular matrix

“…[14] Hydration of bone is reported to vary drastically in disease conditions and aging. [42] The CP experiment is very useful in ssNMR when studying rigid systems such as peptides, proteins, and biological macromolecules. In complex heterogeneous systems such as bone, the CP experiment produces a greater signal-tonoise ratio than a direct detection experiment and results in faster acquisition times.…”