Modeling erosion controlled drug release and transport phenomena in the arterial tissue

22/2009

Modeling erosion controlled drug release and transport phenomena in the arterial tissue

Friday 21st August 2009

Formaggia, Luca; Minisini, Sara; Zunino, Paolo

We introduce and analyze a model for simulating the release of a drug from a polymeric matrix into the arterial tissue, with the aim to describe the processes which occur after the implantation of a cardiovascular drug eluting stent (DES). The main processes occurring in the polymeric matrix are drug dissolution and diffusion. Moreover, surface erosion, which consists in mass loss due to the degradation of the polymeric network, is considered as well. The drug eluted from the matrix is released in the arterial wall, modelled as an homogeneous porous medium. By consequence, we assume that drug molecules are transported by diffusion and convection. Moreover, inside the tissue the reversible reaction of the drug with specific binding sites is taken into account and the coupled problem of mass transfer between matrix and tissue is formulated. It is shown that the mass conservation principle leads to non standard boundary coupling conditions to describe the transfer of the drug both in the solid and dissolved phases. Then, the problem at hand is solved numerically, highlighting the importance of enforcing mass conservation and focusing on the influence of the polymer erosion on the drug release profile and drug distribution in the tissue.