Coupled macromolecular transport and gel mechanics: Poroviscoelastic approach

Designing drug delivery devices or drug delivery protocols poses problems because they are considered to operate in a mechanically static environment. It should consider, however, transport processes in these cases occur in a mechanically dynamic environment since mechanical stimuli may strongly influence transport within soft hydrated materials. A general framework combines fluid and macromolecular transport with the mechanics of hydrated polymer gels or tissue. As an example, the model equations have been created for a spherical geometry to describe the distribution of macromolecules within the gel resulting from a constant pressure or a constant flow infusion source. The model describes the overall average profiles of the interstitial fluid pressure, velocity and solid matrix dilatation, displacement, and stress, as well as macromolecular distribution. The basic theory provides new insight into understanding the transport of macromolecules within mechanically stimulated polymeric gets and tissues and, therefore, represents a valuable tool for designing and engineering novel drug delivery systems, as well as optimization of drug delivery protocols to be used in detection and treatments.