Light activated microbubbles for imaging and microsurgery

Imaging and microsurgery procedures based on the photoacoustic effect have recently attracted much attention for cancer treatment. Light absorption in the nanosecond regime triggers thermoelastic processes that induce ultrasound emission and even cavitation. The ultrasound waves may be detected to reconstruct images, while cavitation may be exploited to kill malignant cells. The potential of gold nanorods as contrast agents for photoacoustic imaging has been extensively investigated, but still little is known about their use to trigger cavitation. Here, we investigated the influence of environment thermal properties on the ability of gold nanorods to trigger cavitation by probing the photoacoustic emission as a function of the excitation fluence. We are confident that these results will provide useful directions to the development of new strategies for therapies based on the photoacoustic effect.