Magnetic Microcapsules for in Vitro Testing as Carrier for Intravascular Administration of Anticancer Drugs : Preparation and Physicochemical Properties

The preparation of anticancer agent-loaded microcapsules magnetically responsive to applied magnetic fields is described, together with some biophysical and biochemical data. The ethylcellulose-walled microcapsules containing magnetite (Fe3O4, as a ferrofluid) and anticancer agents had a diameter of 0.2-0.6μm (mean diameter, 0.308μm). The retention of these microcapsules by magnetic fields was measured in an in vitro model of the human circulation system. The apparatus provided steady flow at various rates through various types of horizontally mounted glass capillary tubes. The retention of magnetically responsive microcapsules was also evaluated in terms of the Reynolds number. The microcapsules prepared in this experiment were caught and held with high efficiency at specific sites within a large artery model by using external permanent or electric magnets, and further, the captured microcapsules did not aggregate irreversibly when the electric field was removed.