Measurement of Ion Diffusivity in Intervertebral Disc Using a Two-Point Electrical Conductivity Approach
ABSTRACT The intervertebral disc (IVD) is an avascular structure, relying on diffusion for cellular nutrition. Therefore, understanding
transport in IVD tissue is important for elucidating mechanisms and pathways of nutritional supply to the disc. Here, a new
two-point electrical conductivity approach to measuring the diffusivity of ions in IVD tissues was developed. In order to
test the reliability of this method, the Cl− ion diffusivity in bovine annulus fibrosus (AF) and nucleus pulposus (NP) tissues was determined. For AF, the Cl− ion diffusivity was measured as 7.56 ± 2.12 x 10− 10 m2/sec (n=15), while that in NP was 1.03 ± 0.16 x 10− 9 m2/sec (n=15). Results found here are in agreement with those in the literature for ion diffusion in IVD tissues, indicating
this new method can reliably measure ion diffusivity in IVD tissues.