Computational model of stent-based delivery from a half-embedded two-layered coating

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Pharmacokinetics

Background:

• Drug-eluting stents (DES) are crucial for preventing restenosis after angioplasty.
• Understanding drug release kinetics and tissue retention is vital for optimizing DES efficacy.
• Interstitial flow in surrounding tissues can significantly influence drug distribution from implanted devices.

Purpose of the Study:

• To develop a computational model simulating drug elution and retention from a two-layered DES.
• To investigate the impact of interstitial flow on drug distribution within porous media.
• To analyze the role of two-layered coatings in enhancing drug efficacy and retention.

Main Methods:

• Developed a computational model incorporating unsteady diffusion for free drug within coatings.
• Modeled drug transport in tissue as unsteady convection-diffusion-reaction.
• Applied the immersed boundary method (IBM) in a marker-and-cell (MAC) formulation to solve governing equations.
• Simulated bound drug transport governed by unsteady reaction kinetics.

Main Results:

• The model successfully predicts drug distribution and retention patterns.
• Demonstrated the benefits of a two-layered coating strategy for improved drug delivery.
• Identified key kinetic parameters influencing drug efficacy and retention.
• Results show good agreement with existing stent-based delivery data.

Conclusions:

• Computational modeling provides valuable insights into drug elution from multi-layered DES.
• Two-layered coatings offer a promising approach to enhance drug retention and therapeutic efficacy.
• Interstitial flow plays a significant role in modulating drug distribution and needs to be considered in DES design.