Sonoporation: From the lab to human clinical trials

Therapeutic ultrasound has been in use for over 70 years but has primarily been a thermal modality. Sonoporation, the use of ultrasound and stable gas microbubbles in the size range of 2-10 μm to form transient pores in cell membranes, has been of great interest in the past 15 years. This technique could be used to improve the delivery of current drugs in very localised regions. There are several phenomena behind sonoporation that all occur non-exclusively: push, pull, jetting, inertial cavitation, shear and, translation. Pre-clinical work has shown that sonoporation can be used to reduce primary tumour burden and inhibit metastatic development. Our clinical trial showed that ultrasound in combination with microbubbles and chemotherapy can effectively double the number of chemotherapy cycles patients can undergo, meaning that the patients were healthier for a longer period of time. Nevertheless, sonoporation is still in its infancy and there is vast room for improvement in both the areas of microbubbles and ultrasound.