Abstract: Controlling the cavitation phenomenon in water-microparticles suspension is a key requirement for the
improvement of the existing ultrasonic therapies and the emergence of new therapeutic application, such as drug de-
livery and cell labcling.ln this paper, the effects of two groups of microparticles wrere suspended in Milli-Q water on
the degree of inertial cavitation due to focus ultrasound were investigated.The first group is three different diameters
of iron oxide nanoparticles were prepared by means of classical co-precipitation in dextran T40 solution. Sonication of
samples was pertormca using continuous wave generatca by a 1.37 MHz-focused transaucer. The inertial cavmanon
threshold was measured before and after seeding with almost spherical solid balls of diameters from 68 nm up to 25
µm in the presence and absence of nanoparticles. Result show that the cavitation dose increasing when the presence
of particles within a liquid and cavitation dose are strongly related to the particle properties such as size, the fines
scale surface structures at 0. 5 mg/mL concentration.