Bilayer alteration from ultrasound-induced microbubble cavitation

The ability of ultrasound-induced cavitation of microbubbles to impact cells is firmly established, but the mechanism by which the acoustic phenomena affects the phospholipid bilayers are not fully understood. Here, we examine the interactions of acoustically driven microbubbles by themselves and in two other different architectures: microbubbles mixed with liposomes and microbubbles tethered to liposomes. Using a combination of ultrasound acoustic spectra and the Wrenn modified RPNNP colloidal model, we observe the effects of microbubble size distribution, radius, and shell chemistry, along with ultrasound frequency and peak negative pressure on the cavitation behavior of the microbubble. We identify the ultrasound intensities corresponding to stable and inertial cavitation and concomitant acoustic microstreaming and shockwave to reversible and irreversible pore formation, respectively, for each architecture.