Optimization of Field-Free Point Position, Gradient Field and Ferromagnetic Polymer Ratio for Enhanced Navigation of Magnetically Controlled Polymer-Based Microrobots in Blood Vessel

Abstract

Microscale and nanoscale robots, frequently referred to as future cargo systems for targeted drug delivery, can effectively convert magnetic energy into locomotion. However, navigating and imaging them within a complex colloidal vascular system at a clinical scale is exigent. Hence, a more precise and enhanced hybrid control navigation and imaging system is necessary. Magnetic particle imaging (MPI) has been successfully applied to visualize the ensemble of superparamagnetic nanoparticles (MNPs) with high temporal sensitivity. MPI uses the concept of field-free point (FFP) mechanism in the principal magnetic field. The gradient magnetic field (|∇B|) of MPI scanners can generate sufficient magnetic force in MNPs; hence, it has been recently used to navigate nanosized particles and micron-sized swimmers. In this article, we present a simulation analysis of the optimized navigation of an ensemble of microsized polymer MNP-based drug carriers in blood vessels. Initially, an ideal two-dimensional FFP case is employed for the basic optimization of the FFP position to achieve efficient navigation. Thereafter, a nine-coil electromagnetic actuation simulation system is developed to generate and manipulate the FFP position and |∇B|. Under certain vessel and fluid conditions, the particle trajectories of different ferromagnetic polymer ratios and |∇B| were compared to optimize the FFP position.

Solid–Liquid State Transformable Magnetorheological Millirobot

“…Cardiovascular diseases, such as heart attack, stroke, and angioma, are the leading cause of death globally. − A magnetic soft millirobot based on elastomers can directly access difficult-to-reach vascular for minimally invasive therapeutic operations. − However, it is restricted by its predesigned shape and limited deformability, which is still challenging to be reconfigured in situ and navigated inside narrow and enclosed vasculature . Here, with good deformability and adaptive mobility in confined regions, the MRF-Robot was proposed to automatically navigate in phantom vascular structures for on-demand liquid-drug delivery, active thrombus clearance, and effective fluid-flow blockage, as shown in Figure c,d and Video S6.…”

Superparamagnetic Iron Oxide Nanoparticles (SPION): From Fundamentals to State-of-the-Art Innovative Applications for Cancer Therapy

“…The tumoral magnetic-targeting ability was shown in vivo using Cy5.5-labelled SPION-exosomes through a significant increase of the fluorescence signal at the tumoral area when an external magnetic field (1 T) was applied. Micro/nano-scale robots [ 97 ] can effectively convert magnetic energy into locomotion [ 98 ] and can be used to support drug delivery vehicles, particularly in the case of cancer [ 37 ]. Recent progress of untethered mobile micromotors highlighted huge potential for targeted drug delivery in vivo.…”

A Review of Microrobot’s System: Towards System Integration for Autonomous Actuation In Vivo

“…MPI is an imaging method based on magnetic particles that can be actuated and functionally targeted for microrobots in drug delivery and situ sensing applications [ 68 , 69 ]. Le et al [ 70 ] have designed a real-time 2D MPI for electromagnetic navigation, which monitored Resovist particles at 45 to 65 nm (5 nm core) in real-time ( Figure 7 D).…”