Numerical study on drug delivery vehicle motion characteristics in tumor-defective blood vessels using arbitrary Lagrangian-Eulerian Algorithm

This study presented numerical study on the motion of drug delivery vehicle (DDV) in blood vessel based the enhanced permeability and retention (EPR) effect due to the tumor-defective blood vessel. Instead of traditional particle tracing, the arbitrary Lagrangian-Eulerian Algorithm (ALE) was employed in this study to account for the force coupling between the moving DDV and blood flow. The ALE and Navier-Stokes modules facilitated by COMSOL software were employed to carry out the numerical simulations. The computational domain was treated as two-dimensional containing three trans-cellular holes caused by the tumor tissue growth. Motions of both spherical and rod-like DDV were considered in this study. The DDV was considered to enter the tumor tissues when it traveled through the defective opening gaps. The simulated results indicated that the initial locations and size played importation roles on governing the motion of DDV. The DDV had greater chance to travel through the opening gaps when its initial location was close to the vessel wall and its diameter ranged between 20 and 100 nm. The numerical simulations also demonstrated that there was significant difference on the DDV trajectories between ALE and particle tracing computations. The motion characteristics of the rod-like DDV was similar to that of its spherical counterpart except the inclusion of rotational motion. The rod-like DDV had less chance of entering the tumor tissue as compared with the spherical DDV because of its rotational motion.