ROLE OF PARTICLE SIZE, STIFFNESS, AND BLOOD FLOW VELOCITY ON MARGINATION OF NANOSCALE DRUG CARRIERS

Abstract

Targeted delivery of nanoscale drug carriers is becoming increasingly recognized as an important technology in the treatment of various diseases. The delivery efficiency depends on the ability of the particles drifting in blood flow toward the vascular endothelium and adhering to the specific sites. It is important to identify and understand the key factors that affect this margination process. In this study, the motion and margination of deformable drug carriers, e.g., liposomes in a cell-rich medium, have been investigated with an operator-splitting finite element method. Interactions between particles and fluid are implemented using an immersed boundary approach. We numerically evaluate the effect of particle and flow parameters, such as carrier size, carrier stiffness, and blood flow velocity, on the margination properties of drug carriers. Both the fluid–body interactions and cell–carrier interactions are fully considered. Overall, we observe a waterfall phenomenon which is crucial in the margination for the carriers to reach the cell-free layer (CFL) near the vascular endothelium. Simulation results show that smaller and stiffer carriers display higher tendency of margination and high flow velocity facilitates this process. This investigation provides insights of the margination mechanism, which offer valuable information in predicting the optimum parameters for the design of effective drug delivery systems.