Mechanism: The science behind SonoTran
SonoTran® exploits a mechanical effect known as sustained inertial cavitation to actively pump therapeutic agents into and throughout solid tumours.
Inertial cavitation refers to the rapid expansion and subsequent collapse of bubbles under the effect of an ultrasound field. Sustained inertial cavitation results in the transfer of momentum from the bubbles into the surrounding medium. This causes a net micro-streaming effect that can be used to propel therapeutic agents and other Sonosensitive Particles lying in the vicinity of the collapsing bubble.
OxSonics’ proprietary Sonosensitive Particles have been developed to carry pre-formed stabilised gas bubbles to enable sustained levels of inertial cavitation using low (quasi-diagnostic) ultrasound intensities at tumour sites. These particles are co-administered alongside unmodified (un-reformulated) solid tumour therapeutic agents. By virtue of their optimal size (400-500nm), the Sonosensitive Particles circulate in the blood stream, but can also “extravasate” (exit blood vessels) through the leaky endothelium of the vessels in solid tumours. Because the Sonosensitive Particles naturally re-stabilise gas on their surface following collapse, the process is repetitive through successive ultrasound pulses and this enables gradual active convection of the drug to distances of greater than 200 microns from blood vessels into tumours.
These features combined have the potential to overcome two of the greatest limitations of solid tumour cancer therapy. In particular, cavitation-mediated microstreaming has been shown to enable accumulation of a greater proportion of the administered dose from the blood stream into the tumour; and improved penetration of the drug beyond the perivascular space to tumour cells lying as far as 150 microns from the nearest blood vessels.