ABSTRACT

In this chapter we describe an analytical approach that can be used to study solute  diffusivity as a function of the tissue composition surrounding a device implanted  in normal, aged, damaged, or diseased brain. The method is capable of resolving  changes in solute diffusivity and cellular composition at the scale of a few microns.  In this chapter we describe the key features of the method including a quantitative  imaging and modeling approach that can be used to assess extracellular diffusion  surrounding a model  implant, and we illustrate how the approach can be used to  study the influence of living cells on tissue remodeling and solute transport. Available evidence suggests that the approach may be useful in sorting out the intricacy  of  the  foreign body  response,  as well  as  examining how soluble  factors  released  from various types of transplanted cells affect brain tissue remodeling and regional  regeneration in the central nervous system.