High resolution q-space imaging studies of water in elastin.

We report on the direct measurement of the molecular diffusion coefficients of water confined to purified bovine nuchal ligament elastin by high resolution q-space NMR imaging. The experimental data indicate that water trapped within an elastin fiber has two distinguishable molecular diffusion coefficients. The component with the slowest mobility has a diffusion coefficient on the order of 10(-6) cm(2)/s that varies inversely with the diffusion time and is seen to reduce near 37 degrees C. The component with higher mobility has a diffusion coefficient reminiscent of free water but is observed to also behave similarly at 37 degrees C. From our experimental data we extract the surface-to-volume ratio of pores within elastin and associated changes as a function of temperature.