Remote Positioning of Spherical Alginate Ferrogels in a Fluid Flow by a Magnetic Field: Experimental and Computer Simulation

This work belongs to the development of mechanical force-responsive drug delivery systems based on remote stimulation by an external magnetic field at the first stage, assisting the positioning of a ferrogel-based targeted delivery platform in a fluid flow. Magnetically active biopolymer beads were considered a prototype implant for the needs of replacement therapy and regenerative medicine. Spherical calcium alginate ferrogels (FGs)similar to 2.4 mm in diameter, filled with a 12.6% weight fraction of magnetite particles of 200-300 nm in diameter, were synthesized. A detailed characterization of the physicochemical and magnetic properties of FGs was carried out, as were direct measurements of the field dependence of the attractive force for FG-beads. The hydrodynamic effects of the positioning of FG-beads in a fluid flow by a magnetic field were studied experimentally in a model vessel with a fluid stream. Experimental results were compared with the results of mathematical and computer modeling, showing reasonable agreement. The contributions of the hydrodynamic and magnetic forces acting on the FG-bead in a fluid flow were discussed. Obtained forces for a single ferrogel implant were as high as 0 to 10(-4) N for the external field range of 0 to 35 kA/m, perfectly in the range of mechanical force stimuli in biological systems.

Automated summary

This study presents the development of a mechanical force-responsive drug delivery system that utilizes an external magnetic field for remote stimulation, facilitating the positioning of a targeted delivery platform in fluid flow. Through experimental and modeling studies, the hydrodynamic and magnetic forces acting on the delivery platform in fluid flow were investigated, revealing their effectiveness within the range of mechanical force stimuli in biological systems.