Abstract
The rate-limiting step in the delivery of nutrients to osteocytes and the removal of cellular waste products is likely diffusion. The transport of osteoid water across the mineralized matrix of bone was studied by proton nuclear magnetic resonance spectroscopy and imaging by measuring the diffusion fluxes of tissue water in cortical bone specimens from the midshaft of rabbit tibiae immersed in deuterium oxide. From the diffusion coefficient (D(a) = (7.8 +/- 1.5) x 10(-7) cm(2)/s) measured at 40 degrees C (close to physiological temperature), it can be inferred that diffusive transport of small molecules from the bone vascular system to the osteocytes occurs within minutes. The activation energy for water diffusion, calculated from D(a) measured at four different temperatures, suggests that the interactions between water molecules and matrix pores present significant energy barriers to diffusion. The spatially resolved profile of D(a) perpendicular to the cortical surface of the tibia, obtained using a finite difference model, indicates that diffusion rates are higher close to the endosteal and periosteal surfaces, decreasing toward the center of the cortex. Finally, the data reveal a water component (approximately 30%) diffusing four orders of magnitude more slowly, which is ascribed to water tightly bound to the organic matrix and mineral phase.
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- Ayasaka N., Kondo T., Goto T., Kido M. A., Nagata E., Tanaka T. Differences in the transport systems between cementocytes and osteocytes in rats using microperoxidase as a tracer. Arch Oral Biol. 1992;37(5):363–369. doi: 10.1016/0003-9969(92)90019-5. [DOI] [PubMed] [Google Scholar]
- Burke E. J., Moreno E. C. Diffusion fluxes of tritiated water across human enamel membranes. Arch Oral Biol. 1975 May-Jun;20(5-6):327–332. doi: 10.1016/0003-9969(75)90022-9. [DOI] [PubMed] [Google Scholar]
- Cooper R. R., Milgram J. W., Robinson R. A. Morphology of the osteon. An electron microscopic study. J Bone Joint Surg Am. 1966 Oct;48(7):1239–1271. [PubMed] [Google Scholar]
- Dillaman R. M., Roer R. D., Gay D. M. Fluid movement in bone: theoretical and empirical. J Biomech. 1991;24 (Suppl 1):163–177. doi: 10.1016/0021-9290(91)90386-2. [DOI] [PubMed] [Google Scholar]
- EDELMAN I. S., JAMES A. H., BADEN H., MOORE F. D. Electrolyte composition of bone and the penetration of radiosodium and deuterium oxide into dog and human bone. J Clin Invest. 1954 Feb;33(2):122–131. doi: 10.1172/JCI102878. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ELLIOTT S. R., ROBINSON R. A. The water content of bone. I. The mass of water, inorganic crystals, organic matrix, and CO2 space components in a unit volume of the dog bone. J Bone Joint Surg Am. 1957 Jan;39-A(1):167–188. [PubMed] [Google Scholar]
- HOLMES J. M., DAVIES D. H., MEATH W. J., BEEBE R. A. GAS ADSORPTION AND SURFACE STRUCTURE OF BONE MINERAL. Biochemistry. 1964 Dec;3:2019–2024. doi: 10.1021/bi00900a042. [DOI] [PubMed] [Google Scholar]
- Knothe Tate M. L., Knothe U. An ex vivo model to study transport processes and fluid flow in loaded bone. J Biomech. 2000 Feb;33(2):247–254. doi: 10.1016/s0021-9290(99)00143-8. [DOI] [PubMed] [Google Scholar]
- Knothe Tate M. L., Niederer P., Knothe U. In vivo tracer transport through the lacunocanalicular system of rat bone in an environment devoid of mechanical loading. Bone. 1998 Feb;22(2):107–117. doi: 10.1016/s8756-3282(97)00234-2. [DOI] [PubMed] [Google Scholar]
- Marino A. A., Becker R. O., Bachman C. H. Dielectric determination of bound water of bone. Phys Med Biol. 1967 Jul;12(3):367–378. doi: 10.1088/0031-9155/12/3/309. [DOI] [PubMed] [Google Scholar]
- Maroudas A. Distribution and diffusion of solutes in articular cartilage. Biophys J. 1970 May;10(5):365–379. doi: 10.1016/S0006-3495(70)86307-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mueller K. H., Trias A., Ray R. D. Bone density and compostiton. Age-related and pathological changes in water and mineral content. J Bone Joint Surg Am. 1966 Jan;48(1):140–148. [PubMed] [Google Scholar]
- Neuman W. F., Neuman M. W. Studies of diffusion in calvaria. Calcif Tissue Int. 1981;33(4):441–444. doi: 10.1007/BF02409468. [DOI] [PubMed] [Google Scholar]
- SMITH J. W., WALMSLEY R. Factors affecting the elasticity of bone. J Anat. 1959 Oct;93:503–523. [PMC free article] [PubMed] [Google Scholar]
- Sasaki T., Yamaguchi A., Higashi S., Yoshiki S. Uptake of horseradish peroxidase by bone cells during endochondral bone development. Cell Tissue Res. 1985;239(3):547–553. doi: 10.1007/BF00219233. [DOI] [PubMed] [Google Scholar]
- Timmins P. A., Wall J. C. Bone water. Calcif Tissue Res. 1977 May 31;23(1):1–5. doi: 10.1007/BF02012759. [DOI] [PubMed] [Google Scholar]
- van der Graaf E. R., ten Bosch J. J. Temperature dependence of water transport into the mineralized matrix of freeze-dried human dentine. Arch Oral Biol. 1991;36(3):177–182. doi: 10.1016/0003-9969(91)90083-7. [DOI] [PubMed] [Google Scholar]
- van der Graaf E. R., ten Bosch J. J. The uptake of water by freeze-dried human dentine sections. Arch Oral Biol. 1990;35(9):731–739. doi: 10.1016/0003-9969(90)90096-s. [DOI] [PubMed] [Google Scholar]