An analysis of coupled multicomponent diffusion in interstitial tissue

A one-dimensional multicomponent kinetic model was developed to simulate the interstitial diffusion of macromolecules in a three component system, consisting of water, the macromolecule and the interstitial matrix. Movement of the individual components was modeled as occurring in finite jumps between discrete low energy wells along paths defined in terms of species occupation. The flow rate was expressed as a function of the local species concentration, the jump distance, and a kinetic frequency parameter. The model, implemented in pseudo-bond graph form, was examined by fitting it to data obtained for the transport of fluorescein tagged dextran to determine the kinetic constants for that specific system.