In vitro experimental investigation on the key parameters for the embolism therapy using the magnetic nanoparticles

In vitro experiments had been conducted to simulate the embolism therapy using the magnetic nanoparticles. In the experiments the main variables are the mass concentration of the particles suspension (0.1%, 0.3%, 0.5%, 0.7% and 1.0%), the flow velocity (40-220 mm/s), the external magnetic induction intensity (0.3, 0.4 and 0.5 T), the nanoparticles diameter (20, 40 and 60 nm). The influences of the above key parameters on the embolism formation are investigated. Meanwhile the pressure oscillations are recorded as well to characterize the human pulse wave during embolism therapy. It is found that the mass concentration determines the embolism formation time, and the concentration of 1.0% is necessary to produce a complete embolism in 200 seconds with the blood velocity of 95 mm/s for 20 nm particles. With a certain external magnetic filed, there is a corresponding maximum critical flow velocity to generate a complete embolism. The critical flow velocity increases with the magnetic induction intensity and the diameter of nanoparticles. The pressure oscillations can characterize the embolism generation and human pulse wave variation. Generally these results are very instructive to specify the operation parameters in the in-vivo animal experiments and clinic embolism treatment.