Nanoparticle Drug Eluting Stents for Treatment of Coronary Re-stenosis in unsteady non- Newtonian magneto-hemodynamics: Computational fluid dynamic simulation

Abstract

Abstract Stent implantation has been a significant breakthrough in the treatment of atherosclerosis. Permanent stent embedding affects the hemodynamics of diseased arteries and can lead to re-stenosis. The deployment of drug eluting stents (DES) has proven to be a very beneficial clinical strategy and has been shown to reduce significantly the possibility of subsequent re-stenosis. The dispensation of drugs designed with biodegradable polymer nanoparticles as carriers has also emerged as a very robust development capitalizing on biocompatibility and increasing capacity to expedite prolonged drug release times. Motivated by this progress, the present study investigates theoretically and numerically the two-dimensional laminar magneto-hemodynamic flow through a DES implanted diseased artery subject to an extra-corporeal (external) magnetic field. The arterial section also features an overlapped stenosis closer to the inlet. Coated hybrid magnetic hybrid nanoparticles are considered by combining titania and alumina. The Carreau model is utilized to simulate non-Newtonian characteristics of blood. To solve the emerging highly non-linear non-dimensional conservation equations with associated boundary conditions, the forward time centred space (FTCS) finite difference technique has been deployed. Comprehensive solutions are displayed for all key flow characteristics in DES implanted arterial transport to aid in understanding the effects of nanoscale, magnetic and biorheological parameters. Comparison between the cases where a stent is present or absent, shows that higher magnitudes of blood flow velocity are achieved by embedding drug eluting stent through diseased artery i. e. greater flow acceleration is achieved. An elevation in hybrid nanoparticle volume fractions (ϕ1, ϕ2) also achieves substantial flow acceleration. The hybrid nanoparticles inclusion in blood is therefore demonstrated to be beneficial for combatting impeded hemodynamics in diseased artery blood circulation. The computations also confirm that via implanting the drug eluting stent, the chances of later re-stenosis are considerably reduced. Detailed graphical plots and tables for a range of emerging parameters are also presented.