A Effect of Focused Ultrasound on the Destruction of Polysterene Particles

Scheinowitz M.
Department of Biomedical Engineering Faculty of Engineering
In our laboratory we have investigated the feasibility of ultrasonic shock wave to selectively destruct ferromagnetic microparticles (Fe3O3, 2.3Ám). We have shown that focused US can effectively destroy this particles in vitro. We run 2 types of analyses in order to understand the effect of the US on the particles: 1) subjective evaluation of the damaged particles using scanning electron microscopy (SEM) analysis; 2) objective analysis which included element detection within the SEM fields. Using the subjective analysis we found a high number of destructed particles within each field (we sum 9 fields of each experiment). However, using the element method, we found a 59% decrease in Fe expression of US destructed particles, though not statistically significant. Thus, in order to draw more definite conclusion we need to increase the number of observations using the same in vitro model before proceeding to in vivo experiments.

Fig. 1. An example of scanning electron microscopy (SEM) of a single field of particles treated with focused US used for subjective analysis of particle destruction.

Fig. 2. An example of elements expression of non-treated (left) and treated (right) particles. The Fe signal in the treated particles is abolished.