Effect of Ionic Strength and Porosity on Ion Diffusion in Agarose Gels

INTRODUCTION Understanding ion diffusion phenomena in biological tissues is important for the study of signal transduction in tissue and cells. However, knowledge on ion diffusion in biological tissues is limited in literature [1-3]. In this paper, we report a new approach to investigating ion diffusion in non-charged porous materials using an electrical conductivity method. The objective of this study is to understand the effect of ionic strength and porosity on ion diffusion in hydrogels. Ion diffusivity is related to electrical conductivity and tissue water content or porosity [4,5]. By measuring electrical conductivity of various gel concentrations in different bathing solutions, one can determine ion diffusivity as a function of gel porosity and ionic strength. Our results show that this new method can be used for determining ion diffusivity in gels and biological tissues.