Optimization of Deformable Magnetic-Sensitive Hydrogel-Based Targeting System in Suspension Fluid for Site-Specific Drug Delivery.

For optimization of the targeting performance of the magnetic hydrogel subject to the magneto-chemo-hydro-mechanical coupled stimuli, a multiphysics model for a suspension fluid flow in a blood vessel is developed, in which a deformable magnetic-sensitive hydrogel-based drug targeting system moves with fluid. In this model, the fluid-structure interaction of the movable and deformable magnetic hydrogel with surrounding fluid flow is characterized through the fully coupled arbitrary Lagrangian-Eulerian algorithm. Moreover, the four physicochemical responsive mechanisms are considered, including hydrogel magnetization, solvent diffusion, fluid flow, and nonlinear large deformation. After the present model is examined by the experimental data in open literature, the transient behaviors of the motion and deformation of the magnetic hydrogel are investigated in suspension flow. It is found that the higher flow velocity and/or the larger hydrogel size accelerate the movement of the hydrogel, while the smaller hydrogel size contributes to the larger swelling ratio. Furthermore, the performance of the magnetic targeting system is optimized for delivering the drug-loaded hydrogel to the desired site by tuning the maximum magnetic field strength, the maximum inlet flow velocity, and the magnet position. Therefore, it is confirmed that the present optimizable magnetic hydrogel-based drug targeting system via the multiphysics model may provide a promising efficient platform for site-specific drug delivery.