Ultrasound contrast agents pushing drug delivery: high speed optical observations

Ultrasound‐activated‐microbubbles can cause transient non‐lethal sonoporation of cells. Studies of influx of cell‐membrane impermeable‐dye, genetic materials, and nanoparticles have confirmed that the action of ultrasound‐microbubbles on the cell‐membrane is to alter both the cell‐permeability. The sonoporation action of ultrasound‐contrast‐agent on cells lies in the fact that microbubbles oscillate while irradiated with ultrasound resulting in a mechanical‐deformation of the cells. Oscillation microbubbles nearby cells have been optically recorded using a microscope and a high‐speed camera. This camera is able to record the MHz oscillation microbubbles and therefore the interaction between oscillation microbubbles and cells. Micro‐mechanical forces generated by the oscillating microbubble may also be used to locally 'push' the drugs into the cells. Ultrasound‐activated‐microbubbles are able to transiently increase the vascular‐endothelial‐layer permeability. These features may be used for future ultrasou...