Targeted delivery of therapeutic agents in a healthy and stenosed patient-specific carotid artery using an external magnetic field

Abstract

In Magnetic Drug Targeting (MDT), an alternative and highly efficient technique to traditional drug delivery methods, therapeutic agents labeled with magnetic particles are transported to a target region using an external magnetic field. A high concentration of agents in the target tissue and their non-dispersion in the body increases treatment efficiency. In this study, targeted delivery of endothelial cells containing magnetic particles in a healthy and stenosed patient-specific carotid artery was studied. The Eulerian-Lagrangian approach was adapted to track the motion of particles and solve fluid equations. The effect of many internal parameters such as plaque morphology (occlusion percentage and the chord length of stenosis) and external parameters such as the strength and the position of the magnetic source, injection time, and the mass of magnetic particles inside each cell on the capture efficiency (CE) of cells was investigated. Results reveal that increasing the mass of magnetic particles in each cell and magnetic field strength enhances the capture efficiency of cells in the target region. Also, shifting the magnetic source location from position 1 (before the carotid sinus) to position 3 (after the carotid sinus) can increase and decrease the number of absorbed cells in the target region and CCA, respectively, both of which are desirable. Investigation of the injection time shows that the CE of cells when injecting in the systole and diastole is approximately the same as their CE when injected in a whole cardiac cycle. For a stenosed carotid artery, the percentage of occlusion is directly related to the CE of cells in the target region. Also, the chord length of stenosis has a direct and inverse relationship with the number of absorbed cells on the plaque surface and in the target region, respectively. Therefore, magnetic particles with higher magnetism or stronger magnetic fields are recommended for the stenosed carotid artery with a more severe occlusion percentage or a longer chord length.