Coated microbubble oscillation using a coupling model at varied ultrasonic parameters and bubble properties for biomedical application

Ultrasound-mediated techniques are very promising tools, and efforts are needed to investigate ultrasound-responsive microbubbles (MBs) for medical applications. Serving a crucial role in optimizing the therapeutic effect, the dynamics of MBs have been a particular focus in present studies. Because MBs often exist in the form of bubble clusters in the ultrasonic field, a precise understanding of the interaction between ultrasound propagation and oscillations of MBs should be paid attention to. In this paper, a model coupling multi-bubble dynamics with nonlinear acoustic wave equations is proposed, and the oscillation of coated MBs is analyzed under different circumstances. In general agreement with experimental results, numerical studies indicate that the MB oscillations vary due to the bubble's initial radius, bubble property, and MB concentration. The promotion or suppression of the concentration on the MB oscillations varies alternately on larger MBs due to changes in the resonance frequency. The stable cavitation dose (SCD) increases with increasing peak negative pressure and pulse length. Moreover, the SCD initially increased with increasing MB concentration and then decreased rapidly as the concentration further increased. This study presents an opportunity for the interplay between MB cavitation, ultrasound parameters and the biological effects for future research from laboratory bench to patient bedside.