The Influence of a Low-Frequency Magnetic Field on Polyelectrolyte Capsules with Magnetite Nanoparticles

Polyelectrolyte microcapsules have been prepared by successively adsorbing oppositely charged sodium polystyrenesulfonate and polyallylamine hydrochloride molecules on the surface of calcium carbonate colloid particles. Capsule shells have been functionalized using Fe3O4 magnetic nanoparticles to control the localization of microcapsules and penetrability of their shells. The penetrability control of microcapsules by means of a low-frequency nonheating magnetic field is based on magnetomechanical action, which is preferable to magnetic hyperthermia for in vivo applications because of its higher penetrability, locality, and safety. The influence of a pulsed low-frequency (50 Hz) sine-wave magnetic field on the microcapsule shell penetrability for fluorescently labeled dextran molecules has been analyzed. It has been found that the shell penetrability grows with decreasing time between magnetic field pulses, thereby increasing the dextran concentration in the shell.