Meeting Abstract

P2-106   -   Micro-scale Fluid Flow in Human Cortical Bone Examined through Reynolds-Matched Flow Testing of 3D Printed Synchrotron μCT Scans Davis, RA*; Gamel, KM; Andronowski, JM; Astley, HC; The University of Akron, Akron, OH; The University of Akron, Akron, OH; Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada; The University of Akron, Akron, OH rad115@uakron.edu https://reeddavis9492.wixsite.com/vitae/

Bone is a dynamic living tissue containing living cells in chemical communication via Haversian canals. Bone continuously undergoes turnover throughout life. During normal locomotion, mechanical deformation of the bone induces fluid movement, aiding diffusion of chemical signals. Microdamage is introduced through such habitual activities. As we age, our bodies become less capable of repairing damaged bone, leading to an accumulation of resorptive areas. This phenomenon is more prevalent in post-menopausal females. We hypothesize that increased cortical porosity in bones of older individuals limits the movement of solutes in the interstitial fluid thus limiting intercellular communication and effective bone repair. To test this, we simulated oscillating fluid flow of a low Reynolds fluid, such as that found in bone, using motor oil moving through magnified 3D printed models of Haversian systems gathered from synchrotron μCT scans of the anterior femur of modern males and females aged between 20 and 95. By infusing a UV fluorescent dye into one end of the system, we were able to quantify the number of oscillations required until the dye was uniformly concentrated throughout the system. Preliminary results indicate that uniform concentration was achieved more rapidly in males than in females and took three times longer in older individuals. This study offers a novel method of examining solute transport through microporosity in bone and may serve as a basis for examining the effects of age-associated bone loss in older individuals, though future models should also incorporate the smaller canaliculi.